CBR F4i not starting (video & info inside). | GTAMotorcycle.com

CBR F4i not starting (video & info inside).

Deimos

Deimos

Well-known member
Hi folks, I'm hoping to get some experienced input on my problem, perhaps even some recommendation on remedying the issue at home before sending the cbr to a mechanic.

Because of the mild winter last year, I tried to stretch the riding season as far as I could and lo and behold my cbr got caught in frozen rain with the cover on it (didn't have a garage at the time). It wouldn't start the next day and hasn't since.

You might ask why it took almost 8 months to address the problem? I've tried to diagnose the problem while in school but didn't have real time until I graduated this past Spring to really start wrenching on her.

Here's the video:

http://www.youtube.com/watch?v=SqdVaV-gdIk


I've so far checked and done the following:

Battery fully charged
Headlight is connected (on the ground in the video)
Gas in tank
Fuel pump primes
Replaced the spark plugs to laser iridiums.
Checked for codes and got nothing back.
Air filter seems fine
Bank angle sensor seems fine (not sure how it would suddenly affect the bike if it was never tipped over)

I recently tried to push start in 2nd gear and the engine struggled to stay turning. Tried twice in 1st gear and it went for a couple of seconds, but again struggled and died. Maybe the starter is the issue?

At this point, I'm about ready to send it to a mechanic.
 
That doesn't sound quite right. Hard to tell from video..but it sounds like there's no compression or the starter isn't engaging? Can you tell if that's the case? Are you sure the plugs are seated properly? The starter sounds like it's not under load.
 
invictus43 said:
That doesn't sound quite right. Hard to tell from video..but it sounds like there's no compression or the starter isn't engaging? Can you tell if that's the case? Are you sure the plugs are seated properly? The starter sounds like it's not under load.
Click to expand...

+1. Nothing more to add them this.
 
invictus43 said:
That doesn't sound quite right. Hard to tell from video..but it sounds like there's no compression or the starter isn't engaging? Can you tell if that's the case? Are you sure the plugs are seated properly? The starter sounds like it's not under load.
Click to expand...

I wouldn't know where to begin since I don't have the tools or know-how to perform a compression test or examine the starter.

Just a friendly fyi, the bike didn't start with the old plugs either. I think I did the new plug installation properly albeit I didn't have a torque wrench, just went by hand until I met resistance then used a wrench to tighten it a quarter turn.

djltoronto said:
Sounds like someone took out all the spark plugs.
Click to expand...

I did put new plugs in but can assure you the bike had the same symptoms before the replacement plugs were installed.
 
Yep I have to agree, cranking way to fast and dosnt sound like anything holding back.
If plugs are tight I'm gonna say timing chain let go or valves bent if the tensioner let go.
There is defiantly a lack of compression there.
I'm gonna say your into something mechanically wrong.
Your gonna defiantly have to run a wet and dry compression test. If there is anyway to see if the cams/valves are moving while cranking this will give you a quick diag if the chain is still intact.
 
Last edited:
***UPDATE***

The bike is fixed. I sent it into cycle werx on bloor/keele.

They picked up the bike.
They did a compression test and found all cylinders to be below PSI: 60 60 80 80
Leak down test found that the valves and combustion chamber were dirty from carbon build up. They flushed out everything along with the old gas.
Cleaned up the air filter too. Also suggested not to use 87 octane, instead 89/91 to avoid carbon build up.

All in all, I paid $429.

Tom and the gang did good work.

Cheers!
 
DSoup said:
Is there a way Deimos could have done this himself at home?
Click to expand...

Was wondering that myself. Is this a case where Seafoam that so many rant & rave about might have done the trick? Not being a wise-guy - I've never had
occasion to try it, but there sure seems to be lots of people who swear by the stuff,
 
Seafoam won't clear that amount of carbon buildup. If it has built up enough that it's preventing the valves from closing then the only way is to manually clean the valves. This can be done at home if you are mechanically inclined, but does require some specialized equipment. I wouldn't recommend it for the average Joe.

Seafoam could have been used as a preventative measure, run some every few tanks of gas and it will help slow down the buildup.
 
DSoup said:
Is there a way Deimos could have done this himself at home?
Click to expand...

Preventative maintenance would've gone a long way I suppose. But without the tools or knowledge to diagnose the problem...well, mechanic is the last option.

Ed In Mississauga said:
Seafoam won't clear that amount of carbon buildup. If it has built up enough that it's preventing the valves from closing then the only way is to manually clean the valves. This can be done at home if you are mechanically inclined, but does require some specialized equipment. I wouldn't recommend it for the average Joe.

Seafoam could have been used as a preventative measure, run some every few tanks of gas and it will help slow down the buildup.
Click to expand...

+1
 
Ed In Mississauga said:
Seafoam won't clear that amount of carbon buildup. If it has built up enough that it's preventing the valves from closing then the only way is to manually clean the valves. This can be done at home if you are mechanically inclined, but does require some specialized equipment. I wouldn't recommend it for the average Joe.

Seafoam could have been used as a preventative measure, run some every few tanks of gas and it will help slow down the buildup.
Click to expand...

Unless I read it wrong, the shop did not remove the head to manually clean the valves, they just flushed out the old gas and fired it up.
 
Deimos said:
Also suggested not to use 87 octane, instead 89/91 to avoid carbon build up.
Click to expand...

I don't mean to advise against their advice, but why would you ever use any fuel other than what is recommended?

I don't know if you have any motor work done that requires the use of higher octane fuel, I just don't know why someone would recommend higher octane!

higher octane does not "clean out carbon" - just like it doesn't "clean out injectors or carburetors"
 
djltoronto said:
Unless I read it wrong, the shop did not remove the head to manually clean the valves, they just flushed out the old gas and fired it up.
Click to expand...

$400+ :( ouch....
 
Flushing out old gas won't help clean out carbon... plus they likely wouldn't have known it was carbon buildup until they removed the head. If the compression was that low on all 4 cylinders the only way to clean it up would have been to remove the head. A good mechanic could have easily removed the head and cleaned the valves in 3 hours or so... that along with 2 hours of diagnostic time would generally line up with that pricing at $80/hour.

djltoronto said:
Unless I read it wrong, the shop did not remove the head to manually clean the valves, they just flushed out the old gas and fired it up.
Click to expand...
 
Ed In Mississauga said:
Flushing out old gas won't help clean out carbon... plus they likely wouldn't have known it was carbon buildup until they removed the head. If the compression was that low on all 4 cylinders the only way to clean it up would have been to remove the head. A good mechanic could have easily removed the head and cleaned the valves in 3 hours or so... that along with 2 hours of diagnostic time would generally line up with that pricing at $80/hour.
Click to expand...

Maybe that's what was done, I don't know. Didn't sound like it from the OP's post.
 
djltoronto said:
Maybe that's what was done, I don't know. Didn't sound like it from the OP's post.
Click to expand...

Yep, receipt was billed at 4 hours for diag+valve/combustion chamber cleaning+air filter and towing.
 
djltoronto said:
I don't mean to advise against their advice, but why would you ever use any fuel other than what is recommended?

I don't know if you have any motor work done that requires the use of higher octane fuel, I just don't know why someone would recommend higher octane!

higher octane does not "clean out carbon" - just like it doesn't "clean out injectors or carburetors"
Click to expand...

You forgot to add that higher octane doesn't give you any more power or fuel efficiency either, assuming the engine is designed for 87. A lot of myths floating around out there, many times spread by people that should know better.

I would also be inclined to say the shop did not pull the head. I imagine if they did, they would replace the head gasket at the same time. That makes me wonder how they unseized the valves.
 
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