Advice/Help on Engine Rebuild of an '03 GSX750F Katana | GTAMotorcycle.com

Advice/Help on Engine Rebuild of an '03 GSX750F Katana

WestBrantKid

WestBrantKid

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I've been talking about rebuilding the engine on my Katana 750 for a couple of years now because I can hear what I'm sure is my timing chain rattling on take-off. After building a shed this summer, I'm finally freeing up space in the garage to give myself room to work, and I want to start on this rebuild.

The engine has 63,000 kms and runs great except for the rattle, so it likely only needs a chain. However, I'd like to make the bike like new again and get another 20 years out of it. I'm unsure if I'll need any specialty tools or if I should order OEM parts versus performance parts. Should I consider oversized rings to make up for wear?

My mechanical experience is somewhat limited. I used to be pretty handy with four-wheeled vehicles and a wrench. I’ve chained engines and transmissions in several pre-90's vehicles, diagnosed and fixed engine issues, and done my own brakes and oil changes all my life. However, I’ve never rebuilt an engine, and my motorcycle-related mechanical work only began about four years ago. Since then, I’ve:

• Wired in a Denali power system
• Installed heated grips
• Done the brakes
• Replaced the chain and sprockets
• Replaced fork seals
• Changed and balanced tires
• Completed a few other simple tasks

I also have an IQ of 132 (or did 20 years ago 😅), but that's paired with a memory like a goldfish, laziness, and poor organizational skills. I can usually figure things out, then forget how to put things back together. Because I struggle with keeping notes, I plan to attempt this rebuild with a camera to refer back to when my memory or note-taking fails me. (Is this memory thing just me, or is it common?)

As you can see, I have limited experience for this task and absolutely no formal training. I have no friends or family with experience I can lean on. I know I can count on the members of this forum for advice, but that can sometimes be slow and unreliable.

I'm wondering if there is anyone with profound knowledge in rebuilding motorcycle engines that I could lean on when I need help. I’d appreciate the ability to contact someone directly, through email or text, for advice when I get stuck. If you live near Brantford and can drop in, that would be a bonus!

I'm not too scared of messing up the rebuild, but I really want to succeed. I’m treating this as a learning experience. I have a parts bike with a complete and running 750 with 55,000 kms, so that’s my plan B. If I succeed with this rebuild, I plan on rebuilding that one too, so I'll have a spare sitting on the shelf.

I likely won't be starting this project for a couple months, and it'll be an evening and weekend project.

Thanks to ChatGTP for re-writing this post for me so it's legible! 🤣
 
Lots of people here with a ton of experience. Tons of pics is a great idea. A system to organize removed bolts is a great idea (egg cartons, plastic boxes, labeled ziploc bags, etc). Check calibration on your torque wrenches at multiple points (eg 20% of scale, 50% of scale, 80% of scale) prior to starting the rebuild.

How much budget is available for this project? What do you have for measurement tools? Oversized rings seems like a terrible idea to me but others with more experience will chime in. If you want to do the best learning/outcome you can get for minimal money, I would pull it apart and measure bores/pistons (top/bottom/ovality/etc), clean the hell out of everything (no abrasives or you will kill it), weigh everything and see if the balance is close. I wouldn't be mixing and matching used parts as they've worn together at this point. Check flatness of head/block. If bores or decks are worn badly, realistically you are into a machine shop to fix it.

If you want to reduce the effort required, deal with the timing tensioner and inspect what you can without coming completely apart. Pull the head so you can inspect/clean everything. That will be far faster than going all the way with valves and pistons sitting on the bench.
 
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The only profound knowledge I can impart is to ask this question on a Suzuki Katana forum that should be filled with 750 owners, some of which have probably done it before. They'll be able to give you insight on how easy/difficult various aspects would be so you can decide how deep to go, as every motor is different. At least you are starting off with the right attitude that you know you don't know enough. I cringe when I see others who think "an engine is an engine".
 
Relax said:
The only profound knowledge I can impart is to ask this question on a Suzuki Katana forum that should be filled with 750 owners, some of which have probably done it before. They'll be able to give you insight on how easy/difficult various aspects would be so you can decide how deep to go, as every motor is different. At least you are starting off with the right attitude that you know you don't know enough. I cringe when I see others who think "an engine is an engine".
Click to expand...
On that note, I don't know what I don't know but could he start with an old gsxr 750 motor? Were they similar packaging? Cost to rebuild should be similar, outcome should be a much bigger smile.
 
Others here will have a LOT more experience than me on the specifics of your rebuild, but I can share some lessons I learned taking a beat up street RC51 and converting it to a track bike. I never got as far as splitting cases or removing heads, but I did get pretty deep, including swapping swingarms, adjusting valves, installing a slipper clutch, new suspension front and rear, swapping brake master cylinders for Brembo, rebuilding calipers, replacing much of the cooling system, and installing race bodywork (the last was probably the most frustrating part, as it needed modification to fit) among many others.

For me, the the lessons learned were:

- Get a lift. I bought mine on sale from Princess Auto, and it made doing the work sooooooo much easier. You can make do with a home-built plywood table, but being able to quickly and easily adjust the height so you can go from trying to work down from up top to up from the bottom was incredibly helpful. The money I spent on that lift was the best I spent on the project.
- Get a paper factory service manual and follow it to the letter. The original service manuals for the RC51 go for stupid money online, so I found a PDF copy and had it printed and bound at Staples. Being able to make notes in the margins was helpful, and so much easier with greasy hands to manage than looking at a PDF on a tablet.
- Buy three good torque wrenches, a baby one, a normal one, and a big boy. Just because they say they go from 2-300 lb-ft doesn't mean they're accurate at the extremes. Be religious about using them, as wrist torque may work most of the time, but you don't want to discover that bolt that is impossible to reach once buttoned up is rattling loose later, or breaks under vibration due to stretching. You'll use the baby one a lot more than you think, the normal one a lot, and the big one rarely but for really important stuff like swingarm bolts and axles.
- I bought a benchtop bin organiser and sorted components by bin. Right front brake caliper and bits in one, tank bolts in another, etc. For really fussy stuff, I used the old poke the bolts in cardboard method, but that came up less often than I expected.
- I also bought a heavy workbench that was very helpful. Having a solid and clean/clear space where you can disassemble bits makes it way easier, especially if you need to leave a section and come back to it multiple times. I bolted a vice to mine and tucked a bench grinder in the corner, the former I used a LOT, the latter only for some basic fabrication work later.
- Stock up on basic stuff, different kinds of grease, etc. that gets called out in the service manual.
- Finding some parts can be a challenge on older bikes, especially consumables. Try to find a Facebook owners group if you can. The RC51 group was a lifesaver for both advice and access to parts that Honda no longer stocks. And odds are, if you run into a headache, someone else has already been there and can give some advice on what worked for them.
- Keep a clean and uncluttered workspace as best you can. There's a reason race garages look like surgery theatres. Cleanliness means you can see what you're doing, means parts mate without issue, and is just generally a nicer space to be in and promotes clear thinking. In my case, my garage is tiny and stuffed, but I always made sure the work bench and lift only had the things I needed for the task at hand on it. Unneeded tools got put away, unneeded parts went in the right bin. Always.
- Above all, go slow. Rushing and saying, "good enough", is the enemy. Give yourself lots of time, if you get tired or frustrated then stop and come back, and measure, check, double check, triple check, and check again. You have to be willing to take the time to re-disassemble if something isn't right. In my case, it showed up in getting a rear gear-driven cam alignment wrong by a tooth when reassembling the heads after checking the valves (the arrows lined up, but from the wrong perspective). I was in a hurry to get it done, and I was lucky that the symptom was a bike that wouldn't start, not a bent valve.

Oh, and have fun. I spent a fall, winter and spring doing up mine, and I really loved it. Very satisfying and zen. Lots of moments along the way that were frustrating, but that made it all the more satisfying when it was sorted.
 
GreyGhost said:
On that note, I don't know what I don't know but could he start with an old gsxr 750 motor? Were they similar packaging? Cost to rebuild should be similar, outcome should be a much bigger smile.
Click to expand...

If we're talking about motor upgrades, then I'd be asking those Katana forums if a 7-11 could be done!
 
Priller said:
Others here will have a LOT more experience than me on the specifics of your rebuild, but I can share some lessons I learned taking a beat up street RC51 and converting it to a track bike. I never got as far as splitting cases or removing heads, but I did get pretty deep, including swapping swingarms, adjusting valves, installing a slipper clutch, new suspension front and rear, swapping brake master cylinders for Brembo, rebuilding calipers, replacing much of the cooling system, and installing race bodywork (the last was probably the most frustrating part, as it needed modification to fit) among many others.

For me, the the lessons learned were:

- Get a lift. I bought mine on sale from Princess Auto, and it made doing the work sooooooo much easier. You can make do with a home-built plywood table, but being able to quickly and easily adjust the height so you can go from trying to work down from up top to up from the bottom was incredibly helpful. The money I spent on that lift was the best I spent on the project.
- Get a paper factory service manual and follow it to the letter. The original service manuals for the RC51 go for stupid money online, so I found a PDF copy and had it printed and bound at Staples. Being able to make notes in the margins was helpful, and so much easier with greasy hands to manage than looking at a PDF on a tablet.
- Buy three good torque wrenches, a baby one, a normal one, and a big boy. Just because they say they go from 2-300 lb-ft doesn't mean they're accurate at the extremes. Be religious about using them, as wrist torque may work most of the time, but you don't want to discover that bolt that is impossible to reach once buttoned up is rattling loose later, or breaks under vibration due to stretching. You'll use the baby one a lot more than you think, the normal one a lot, and the big one rarely but for really important stuff like swingarm bolts and axles.
- I bought a benchtop bin organiser and sorted components by bin. Right front brake caliper and bits in one, tank bolts in another, etc. For really fussy stuff, I used the old poke the bolts in cardboard method, but that came up less often than I expected.
- I also bought a heavy workbench that was very helpful. Having a solid and clean/clear space where you can disassemble bits makes it way easier, especially if you need to leave a section and come back to it multiple times. I bolted a vice to mine and tucked a bench grinder in the corner, the former I used a LOT, the latter only for some basic fabrication work later.
- Stock up on basic stuff, different kinds of grease, etc. that gets called out in the service manual.
- Finding some parts can be a challenge on older bikes, especially consumables. Try to find a Facebook owners group if you can. The RC51 group was a lifesaver for both advice and access to parts that Honda no longer stocks. And odds are, if you run into a headache, someone else has already been there and can give some advice on what worked for them.
- Keep a clean and uncluttered workspace as best you can. There's a reason race garages look like surgery theatres. Cleanliness means you can see what you're doing, means parts mate without issue, and is just generally a nicer space to be in and promotes clear thinking. In my case, my garage is tiny and stuffed, but I always made sure the work bench and lift only had the things I needed for the task at hand on it. Unneeded tools got put away, unneeded parts went in the right bin. Always.
- Above all, go slow. Rushing and saying, "good enough", is the enemy. Give yourself lots of time, if you get tired or frustrated then stop and come back, and measure, check, double check, triple check, and check again. You have to be willing to take the time to re-disassemble if something isn't right. In my case, it showed up in getting a rear gear-driven cam alignment wrong by a tooth when reassembling the heads after checking the valves (the arrows lined up, but from the wrong perspective). I was in a hurry to get it done, and I was lucky that the symptom was a bike that wouldn't start, not a bent valve.

Oh, and have fun. I spent a fall, winter and spring doing up mine, and I really loved it. Very satisfying and zen. Lots of moments along the way that were frustrating, but that made it all the more satisfying when it was sorted.
Click to expand...
Good post. You mostly rebuilt the bike around the engine. He's rebuilding the engine but not the bike (yet). That helps him some as he could skip the lift as the engine will be out and he can put it on the bench.

On the service manual front, I try to come up with whatever I can. A factory manual, a haynes, a clymer and compare for important things like torque. Even factory manuals have some errors (and bike specific forums are great for shining light on them).
 
GreyGhost said:
Lots of people here with a ton of experience. Tons of pics is a great idea. A system to organize removed bolts is a great idea (egg cartons, plastic boxes, labeled ziploc bags, etc). Check calibration on your torque wrenches at multiple points (eg 20% of scale, 50% of scale, 80% of scale) prior to starting the rebuild.

How much budget is available for this project? What do you have for measurement tools?
Click to expand...
I only have a torque ratchet for lug nuts. I'll buy one for this project. How do you calibrate them, or check them for accuracy?

Budget: What ever it takes? lol Like I said, I'm bad at organization and planning. I have a line of credit for related costs that I will charge to, and pay-off, as I go. I expect I'll hold a balance by the time this is done, but I'd like to avoid unnecessary costs. The less it costs the better, but I'll be disappointed if it exceeds around $2000. So, I'm sure I'm looking at about $4000+.

I'll set aside some egg cartons and pickup some of those ziploc bags with printable labels. I like that idea. Might be good to have a few jars on hand, too.
 
I wouldn't be rebuilding a motor cuz the cam chain makes noise. First thing I would do is get a factory manual and there is a measurement/spec for the cam chain. If the chain is in spec, fix the tensioner (have you tried resetting the tensioner? They do go out of adjustment and should be reset regularly). If the chain is out of spec, you'll have to remove the crank to replace it. You CAN buy a cam chain with a joiner link, but I don't trust them
What are your compression numbers? 63k kms is enough to need rings. If your compression is less than 140psi consider looking into the issue. Measure the bore (add a thou for hone) and compare that to the specs in the manual. If it's in spec a hone and new rings. too big? bore, hone and oversized pistons and rings.
If you split the cases to do the cam chain: measure and inspect the big ends and mains. You measure using "plastigage"

Yes. that motor is a oil boiler from a '80s GSXR, that's been de-tuned... so any GSx 750/1000/1100, GS1000 or early GSXR 750/1100 bolts in. The early aircooled GS750/850 won't (the one with a kick starter)
i don't think there are any "special" tools required. It's easier if you have an engine stand. To remove the motor from the frame, remove all the bolts, lay the bike on it's side and remove the frame from the motor
I am currently building a GS750 (air cooled) motor, if I can help: just ask
Cometic head gaskets work best and Total Seal sells rings for that bike.... OH YEAH; if you remove the head, you MUST lap the sealing surfaces WITHOUT FAIL... and if I took the head off I would replace the head bolts/studs with oversized tool steel (HSS) studs (Winner's Circle has 'em... CHEAP)
 
GreyGhost said:
Good post. You mostly rebuilt the bike around the engine. He's rebuilding the engine but not the bike (yet). That helps him some as he could skip the lift as the engine will be out and he can put it on the bench.

On the service manual front, I try to come up with whatever I can. A factory manual, a haynes, a clymer and compare for important things like torque. Even factory manuals have some errors (and bike specific forums are great for shining light on them).
Click to expand...
You're right in that the deepest I got was down to a bare frame and engine, everything else except the triple tree was stripped. But even dropping a motor requires tearing a lot of the bike off, I would still want the lift for all that and especially for reassembly. Not to mention, if you're going to have the motor out, you might as well at least check a bunch of other stuff. The one I got is now $900 normally (they have another one for $700), but goes on sale for half off pretty regularly. I'm pretty sure I paid less than $400 for mine, new and on sale. For that money, the headaches it'll save you are worth every penny. Not to mention having it for future work. Every bit of maintenance I do is made easier with the lift, whether it's changing oil, lubing a chain, replacing brake fluid, you name it. Plus, the work you do is better because you can see what you're doing and can get better angles for access.

Mine is probably the best 'tool' I've ever purchased.
 
Relax said:
The only profound knowledge I can impart is to ask this question on a Suzuki Katana forum that should be filled with 750 owners, some of which have probably done it before. They'll be able to give you insight on how easy/difficult various aspects would be so you can decide how deep to go, as every motor is different. At least you are starting off with the right attitude that you know you don't know enough. I cringe when I see others who think "an engine is an engine".
Click to expand...
Before I found this forum, I was in a Suzuki forum, and a Katana forum. The Katana forum had almost no traffic and recently shut down. The Suzuki forum is nearly the same. It's being kept alive by one admin that replies to all new member's posts, and no one else.
The people that keep this forum going are amazing, because this site has great traffic, and lots of friendly, helpful contributors. You should all pat yourselves on the back.
Katana's are basically dead. There's no support, and very limited parts available. That's one of the reasons I'd like to revive this bike now, while I might still get the parts needed for it.
The re-release of the Katana a few years ago made it even harder to find anything on the older models since most search results go to those bikes.
 
FYI, it looks like I'm having a busy day at work today, so I apologist if I don't reply for a while after creating this post.
 
WestBrantKid said:
Before I found this forum, I was in a Suzuki forum, and a Katana forum. The Katana forum had almost no traffic and recently shut down. The Suzuki forum is nearly the same. It's being kept alive by one admin that replies to all new member's posts, and no one else.
The people that keep this forum going are amazing, because this site has great traffic, and lots of friendly, helpful contributors. You should all pat yourselves on the back.
Katana's are basically dead. There's no support, and very limited parts available. That's one of the reasons I'd like to revive this bike now, while I might still get the parts needed for it.
The re-release of the Katana a few years ago made it even harder to find anything on the older models since most search results go to those bikes.
Click to expand...

Have a look on Facebook. I deleted my Facebook profile ages ago, but ended up making a fake name one both for access to the RC51 owners groups and classifieds. I found most smaller model-specific forums have migrated there, sadly.

Edit: looks like there's three Facebook groups, two private. One seems relatively active, says average of 8 posts per day.
 
WestBrantKid said:
I only have a torque ratchet for lug nuts. I'll buy one for this project. How do you calibrate them, or check them for accuracy?

Budget: What ever it takes? lol Like I said, I'm bad at organization and planning. I have a line of credit for related costs that I will charge to, and pay-off, as I go. I expect I'll hold a balance by the time this is done, but I'd like to avoid unnecessary costs. The less it costs the better, but I'll be disappointed if it exceeds around $2000. So, I'm sure I'm looking at about $4000+.

I'll set aside some egg cartons and pickup some of those ziploc bags with printable labels. I like that idea. Might be good to have a few jars on hand, too.
Click to expand...
You can check calibration yourself. There are many ways. You can look on line for detailed methods. In short, I clamp a socket horizontally into the edge of a vise (balls tight). I attach a known weight to a rope/strap and figure out a good distance to use (distance from centre of head to around middle of handle so maybe 24" for my big one). Now I have a known weight (say 40 lbs) at a known distance (2'). Set to 80lbft and connect to socket with handle horizontal. Hang weight gently from measurement point and it should just click. If you have to lift up or push down much to get click/reset, calibration is off. Check with different weights to check throughout the useful range (~20-80% of scale).

Alternatively you can buy an electronic torque measuring adaptor that allows you to use arm strength instead of weights (faster and easier assuming you trust the electronic thing).

EDIT:
Even check new torque wrenches. Take them back if they are off. If you have one outside of warranty that is off, you can adjust calibration (normally hiding under the end cap). Before you adjust, do a sanity check and make sure you are not screwing up. My way is great confirmation of acceptability but you need to think long and hard before recalibrating measurement devices and make sure that there is no error in your procedure or logic.
 
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Priller said:
Oh, and have fun. I spent a fall, winter and spring doing up mine, and I really loved it. Very satisfying and zen. Lots of moments along the way that were frustrating, but that made it all the more satisfying when it was sorted.
Click to expand...
Thanks, Priller. This is some great insight, and I expect will be very useful. Reading this actually got me excited to star, but I still have a ways to go to prep. I hope to have that surgical atmosphere you mentioned.
I have a storage shelf left to build in the shed, then some clearing out to do in the garage. I have multiple standing tool boxes and want to re-organize them to have one the holds all tools related to this project, and to buy tools I can expect to need that I don't already have.
I have a solid 3.5" x 3' x 8' workbench I made by glueing/screwing 2x4s together and sanding it down smooth with a belt sander. It's butted up against a solid, but not nearly as solid, 3' x 5' bench. I also have a bench vise mounted, but I'll need to relocate it. I had the foresight to mount it in front of two 3x4 windows for better lighting during the day.
I'll take you advice on getting the three torque ratchets.
I also downloaded a PDF manual. I think I'll take you advise on printing it. I can print and bind it myself at work. I might even add a custom cover for fun. lol
I'll look into the lift, but I thought about making a rolling stand so I can roll the bike around the garage and get it out of the way easily once the engine is out.
I likely have all the supplies I need (grease, oils, etc.) because, like tools, I like to keep them on my wishlist on the Canadian Tire app so I can buy them when they go on sale for 50-70% off. CT has great sales, and if I buy it when on sale rather then when I need to, I save a lot of money. Although I also end up with lots of things I never use. lol
The organizer sounds like a good investment, too. I'm picturing one with 30 tip-out bins that I could label for screws, rings, washers, small parts, etc.. That's a good idea!
 
bitzz said:
I wouldn't be rebuilding a motor cuz the cam chain makes noise. First thing I would do is get a factory manual and there is a measurement/spec for the cam chain. If the chain is in spec, fix the tensioner (have you tried resetting the tensioner? They do go out of adjustment and should be reset regularly). If the chain is out of spec, you'll have to remove the crank to replace it. You CAN buy a cam chain with a joiner link, but I don't trust them
What are your compression numbers? 63k kms is enough to need rings. If your compression is less than 140psi consider looking into the issue. Measure the bore (add a thou for hone) and compare that to the specs in the manual. If it's in spec a hone and new rings. too big? bore, hone and oversized pistons and rings.
If you split the cases to do the cam chain: measure and inspect the big ends and mains. You measure using "plastigage"

Yes. that motor is a oil boiler from a '80s GSXR, that's been de-tuned... so any GSx 750/1000/1100, GS1000 or early GSXR 750/1100 bolts in. The early aircooled GS750/850 won't (the one with a kick starter)
i don't think there are any "special" tools required. It's easier if you have an engine stand. To remove the motor from the frame, remove all the bolts, lay the bike on it's side and remove the frame from the motor
I am currently building a GS750 (air cooled) motor, if I can help: just ask
Cometic head gaskets work best and Total Seal sells rings for that bike.... OH YEAH; if you remove the head, you MUST lap the sealing surfaces WITHOUT FAIL... and if I took the head off I would replace the head bolts/studs with oversized tool steel (HSS) studs (Winner's Circle has 'em... CHEAP)
Click to expand...
Great info, Thanks!
What do you mean by 'lap the sealing"?
Do the GSXR 750 "oil boiler" engine parts also fit the GSXF 750? That would make parts-finding much easier. Maybe upgrading, too.

I'll have to get a compression tester, I don't currently have one.
I'm unfamiliar with the tensioner. Is this adjustable without cracking the engine?
I'll look into a plastigage. I've never heard of it, but it sounds like I could use one.
 
WestBrantKid said:
Great info, Thanks!
What do you mean by 'lap the sealing"?
Do the GSXR 750 "oil boiler" engine parts also fit the GSXF 750? That would make parts-finding much easier. Maybe upgrading, too.

I'll have to get a compression tester, I don't currently have one.
I'm unfamiliar with the tensioner. Is this adjustable without cracking the engine?
I'll look into a plastigage. I've never heard of it, but it sounds like I could use one.
Click to expand...
Lap=make flat. Probably cheaper to pay a shop to do it than to figure it out for yourself on a one-off. You need a flat surface and something abrasive to transfer the flatness to your parts. Only takes a few minutes if you have the flat surface but we are talking engineered flat here not just a poured concrete floor. If the flat surface isn't flat, you just make a mess. In a pinch you could probably use a sheet of glass but it's normally got a curve to it so I don't love that idea.

For tensioner, look at service manual. Normally it is far more accessible than engine internals. It can be some work to get to but far far less than a rebuild.

Plastigauge is similar to playdough string but engineered. Lets you measure bearing clearances by squishing the string and then measuring the squished string to find clearance.
 
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