Rick mcadams
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Why would 1 cylinder be running way hotter than the rest 3 r running about 240 an 1 is 275 any help is appreciated
1200 running hot
- Thread starter Rick mcadams
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I second that. I assume you are hitting this with an IR gun while the bike is idling? If so fatten the mix up a little on the hot cylinder, it should cool slightly.
LenP
Member
I have the same symptom but worse. Cylinder 1 header is 375. Did you get this figured out?
Maybe a coolant system flush? And check the radiator for partial obstructions.
The problem with toys such as an IR gun is that they allow you to look into places you don't normally visit and see thing that are probably 'normal' but don't seem right.
Could this be one of those situations?
I'd assume that you are checking this at idle but IMO that is not particularly relevant as it's what happening when the bike is under power that should be considered.
Assuming that the jetting is the same for all cylinders and the idle mixture screws are correct then that is probably something they do.
Put the IR gun away and go back to the beginning. What problems are you getting when riding the bike?
If the bike is performing normally then I suspect you have stumbled on a 'feature' of the engine and it is nothing to worry about.
If you are experiencing a problem (not the temperature differential) please describe what it is.
Many years ago I had to meet a customer who had been giving his car a bit of a thrashing, stopped and immediately opened the bonnet.
He was concerned that the exhaust manifold was glowing red and felt there must be a fault. It took a lot of convincing that this was normal. As we don't normally do what he did by the time we open the bonnet the manifold cools sufficiently to loose the glow.
In the absence of any other symptoms I suspect yours is a similar situation. i.e. we don't normally measure the exterior temperature of the cylinder.
It could jus be that the wall of that part of the water jacket is thicker....
Could this be one of those situations?
I'd assume that you are checking this at idle but IMO that is not particularly relevant as it's what happening when the bike is under power that should be considered.
Assuming that the jetting is the same for all cylinders and the idle mixture screws are correct then that is probably something they do.
Put the IR gun away and go back to the beginning. What problems are you getting when riding the bike?
If the bike is performing normally then I suspect you have stumbled on a 'feature' of the engine and it is nothing to worry about.
If you are experiencing a problem (not the temperature differential) please describe what it is.
Many years ago I had to meet a customer who had been giving his car a bit of a thrashing, stopped and immediately opened the bonnet.
He was concerned that the exhaust manifold was glowing red and felt there must be a fault. It took a lot of convincing that this was normal. As we don't normally do what he did by the time we open the bonnet the manifold cools sufficiently to loose the glow.
In the absence of any other symptoms I suspect yours is a similar situation. i.e. we don't normally measure the exterior temperature of the cylinder.
It could jus be that the wall of that part of the water jacket is thicker....
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LenP
Member
I agree with what you are saying. The bike seems to ride fine. Plenty of power and averaging 32 mpg between fill ups. The only reason I started testing things is because I noticed the right side exhaust is considerably stronger than the left side at idle. Just didn’t seem right to me.
Have you balanced the carbs?
If you still want to measure the temperature then the temperature of the headers at the same place would be more meaningful than measuring at the cylinder heads - as MM said the casting thickness may be different or the coolant flow path different or other reasons.
Again dont expect them to be the same - I'm not sure what temperature difference should be a concern, 10% for sure is fine, more than 30%, hmm not so good.
If you still want to measure the temperature then the temperature of the headers at the same place would be more meaningful than measuring at the cylinder heads - as MM said the casting thickness may be different or the coolant flow path different or other reasons.
Again dont expect them to be the same - I'm not sure what temperature difference should be a concern, 10% for sure is fine, more than 30%, hmm not so good.
LenP
Member
I’m checking the temp on the headers three inches from the head. I installed new plugs and bought a carb tune and synced the carbs, even tried to richen cyl 1 carb, no difference. Gonna check the spark on cyl 1 and do a compression test on all cylinders. I don’t think it’s a major issue but I like my engines to run perfect.
Just gone back to your original post.
That about 10% difference a idle.
The important numbers are when under load. Are there any issues when riding?
If not, then I'd say put the thermometer away and forget about it.
If you start changing the mixture, you are in the realm of "messing with thing I don't understand" so can make things worse or even cause damage. The fact it made no difference kinda confirms this.
That about 10% difference a idle.
The important numbers are when under load. Are there any issues when riding?
If not, then I'd say put the thermometer away and forget about it.
If you start changing the mixture, you are in the realm of "messing with thing I don't understand" so can make things worse or even cause damage. The fact it made no difference kinda confirms this.
