Some carbon around the exhaust Yamaha MT-03 | GTAMotorcycle.com

Some carbon around the exhaust Yamaha MT-03

MacDoc

MacDoc

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The previous owner of my new to me 2017 Yamaha MT-03 was a noob when he bought it and I got the impression he never rode the bike even close to its potential....I think short shifting was the order of the day.
The twin is much fun from 7k up to 12k and seems to like 5th gear over 6th.
In the good old days I'd say the bike was running rich as there is an unevenness running in 6th..not the very even engine feel of 5th.
My RD400 used to feel like that when the plugs were getting fouled.
Almost as if there is a slight miss....wondering at 20k km if plugs could be slightly fouled as bike does not start as easily as I think it should either.
Is carbon build up even a thing with Fi motors? :unsure:
Will take a photo of the exhaust....it's certainly not extreme ...but definitely some carbon around the exit.
Is there an additive maybe could clean any carbon build up?
I've been having fun winding it out where I can purely for diagnostic reasons :rolleyes:
TIA
 
Yup - seller despite buying new - never received a manual or a toolkit. :rolleyes:
Was going to download it tonight. Thanks for the tip.
Any suggestion on brand/type of plugs.
any truth in this
Platinum spark plugs boast longevity and resistance to fouling. Since platinum is harder, it holds its sharp edge much longer than a conventional spark plug, up to 100,000 miles. Platinum spark plugs
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MacDoc said:
Yup - seller despite buying new - never received a manual or a toolkit. :rolleyes:
Was going to download it tonight. Thanks for the tip.
Any suggestion on brand/type of plugs.
any truth in this
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Back to the manual again. It is hard to go wrong with OEM plugs (exact brand and model) and gap. On the other hand, some engines really hate other brands/models of plug. It sucks to do the work and your bike ends up worse.
 
Platinum tipped plugs DO last longer... don't know about 100,000k ... but they DO last longer than non platinum plugs
Don't buy plugs off amazon or aliexpress
Go for ride this weekend when it's warmer to see if it is better... I don't have a lot of faith in the MAP sensors these bikes use
 
Thanks ...this is a minor complaint...the bike is new to me but the combination of a bit of carbon around the exhaust exit, former owner not likely to have pushed the twin at all, and now the manual calls for plug change.
Seems best practice put in OEM plugs and see if any improvement.
Is there any additive for carbon build up??
Appears there might be
I rely on my long term service guy to get the correct OEM part.

Once that is done...interested in this mapping idea.
How is that accomplished. TIA
 
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Platinum or iridium plugs do last longer, which is a significant advantage on bikes where the plugs are difficult to access (think Kawasaki ZX636).
For the street, in most instances they are waste of money IMO.
 
Thanks...I may not live long enough to get advantage of pricey plugs.

Also not sure I mentioned it but starting is not as clean and crisp as I would expect. Now that could be a weakening battery ....this climate is brutal on batteries.
 
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MacDoc said:
Thanks...I may not live long enough to get advantage of pricey plugs.

Also not sure I mentioned it but starting is not as clean and crisp as I would expect. Now that could be a weakening battery ....this climate is brutal on batteries.
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I wouldnt be concerned with a little carbon on the tip (although that us slightly strange in a vehicle with a cat). If you want to dump in a fuel additive to clean out injectors, this video is good. You can watch and learn or just skip to the slide that says "the good" and buy one of those products. It's about 3/4's of the way through iirc.


If you're worried about carbon in the combustion chambers or on the backs of valves, I haven't found a magic liquid that worked. Manual cleaning or walnut blasting works for those circumstamces but it's a pain.
 
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It is really a combination of factors - I suppose I can run an additive first and see if anything changes while I get an appointment for the plugs which are due anyways. 🍿
This is available and looks good.
oilandenergy.com.au

Red Line SI-1 Complete Fuel System Cleaner - 12 Oz.

Red Line SI-1 COMPLETE FUEL SYSTEM CLEANER. World's best fuel cleaner? Many say so. We say try for yourself and see.
oilandenergy.com.au oilandenergy.com.au
 
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Sounds like you are more concerned with the looks of the sooty exhaust tip than the way it runs. It's better to run too rich than too lean. Most fuel additives are a waste of money imho. Just ride it. Here's a pic of the Ural's exhaust tip. Perfectly normal.
20241017_111214.jpg
 
Tells me nothing and it's NOT just the exhaust. :rolleyes: To reiterate...it is a combination of factors including the service suggestion on the plug change at 20km. the starting, the way it is running and the history of the owner.

I don't really care about your opinion on additives or misconceptions of what I'm concerned about .:coffee:
 
MacDoc said:
Tells me nothing and it's NOT just the exhaust. :rolleyes: To reiterate...it is a combination of factors including the service suggestion on the plug change at 20km. the starting, the way it is running and the history of the owner.

I don't really care about your opinion on additives or misconceptions of what I'm concerned about .:coffee:
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Wow. Cranky pants.
 
At the risk of having my opinion shat on ;) I would recommend buying the plugs from your local dealer. If they have good and better options, choose the weapon that makes you happier.
 
My race bike is the mechanically-identical cousin of that bike (R3). Mine is not stock, it has full exhaust with no catalyst, and has been tuned, and it's only below 7000 rpm when trickling through the paddock or waiting on the grid. The muffler is black inside, but there's no visible build-up and nothing comes off with a finger wiped inside it. I am using fuel containing ethanol E10 as that's pretty much all you can get here if you're not buying fuel from a race fuel supplier. I don't know what's common in Australia.

Spark plugs - go ahead and use NGK CR9EIX-9 or CR9EIA-9 iridium plugs if you wish, the bike runs well with them. No real advantage over stock that I can tell, but you won't have to mess with them again. Dealer should have CR9EIA-9 in stock - they've been the standard plugs in a lot of litre bikes, including the R1, over the years.

At 20k, check the air filter - or just replace it. Remove plastic trim panel under rider's seat on left side (3 screws), remove airbox side cover (3 screws), pulls straight out the side.

They can take a second or two of cranking before starting cold - it's normal. If spark plugs need replacement, obviously go ahead and do that, and if cranking speed isn't what it should be and the battery is suspect, go ahead and change that. But even at the best of times, they can take a second or two of cranking before they fire up. The fuel injection calibration for cold starting is very, very lean, just barely enough, for emissions reasons. If anything is the slightest out of kilter, it will take longer cranking. I sorted mine out by having the PowerCommander give it 2% more fuel for the first 5 seconds of crank rotation.

On top of that, hot starting is sometimes an issue. There are certain aspects of the fuel injection calibration on these bikes where I really wonder what Yamaha's calibration folks were thinking. If it takes a second or two of cranking before it starts when hot, holding the throttle slightly open while cranking should clear the rich condition and it should start right up.
 
MacDoc said:
Tells me nothing and it's NOT just the exhaust. :rolleyes: To reiterate...it is a combination of factors including the service suggestion on the plug change at 20km. the starting, the way it is running and the history of the owner.

I don't really care about your opinion on additives or misconceptions of what I'm concerned about .:coffee:
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I'm not sure who this is directed at. How about using the quote button?
 
I'm with @Wingboy. Just ride it.

PXL-20241017-191327763.jpg
 
As I mentioned my service guy will source the correct plugs. Will stick with stock OEM plugs
Brian thanks...useful information especially the starting aspect.
I did have to crack the throttle on a hot start the other day and hearing about the slight delay on cold starts also reassuring.
Will get dealer to change air filter.

Nice day for a 60th anniversary of riding on my 77th bday, 🎂
I get to celebrate twice thanks to dateline.
Screen Shot 2024-10-18 at Oct, 18 2024 8.15.16 AM.jpg
Been a long run ...."some"....more riding to come. 🏍️
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