header temperature?

[spyderrocs]

My headers were way different temps to the touch, so i measured them with a infred temp gun. Numbers one and two were about 100+/- number 3 was 250 and number 4 was 150. This is in farenheight after idling for 2 minutes or so. Obviously this shouldnt be right, so what could it be jetting? Plugs?

[Thomas Kenny]

You should ride it up to full operating temperature, two minutes idling from cold will probably not be enough to get a good read. Just my .02 worth

Gizmo

[GS850_Coug]

Solve the problems in your other posts, then they will likely be the same temps.

[spyderrocs]

i fixed them all, bike starts good now and everything else is all set.

[spyderrocs]

ok took it out for 15 minutes or so. Header temps evened out a little bit, number 1, 2, 4 were around 180 all within about 20 degrees of each other. Number 3 was still extremely high at around 250. should i be concerned? Time for a sync?

[DimitriT]

If you haven't done so, then sync the carbs. Have you adjusted the valve clearance yet? If not, do that before you sync the carbs.

[spyderrocs]

alright valve ajustment and carb sync ill do it this week.

[GS850_Coug]

With one cylinder that hot, the cylinder is running too lean. Could be a leaky intake on that cylinder, a low float, plugged jet, plugged fuel inlet screen, etc. Could also be as simple as adjusting the pilot screw.

[spyderrocs]

i think the cap for the pilot screw on that one cylinder was moved so ill give it a look. 1/4 turn richer right?

[focus frenzy]

yes, and factory pipes are dual wall and it is possible to get eronious readings due to production variables.

[spyderrocs]

the valves have been ajusted all within spec. The pilot was turned out 1/4 a turn. All the spark plugs looked decent that one looked like a brand new plug so i think its running correct. Its just the 100 degree jump thats worrying me. When i put my hand at the tail pipe the exhaust comming out is hotter on the right than the left tail pipe?

[GS850_Coug]

Do the temps even out after riding at higher RPMs? If so, then keep adjusting the pilot screw out little by little. Keep checking the plug for fouling to ensure you don't go too far. You may also have a plugged passage in the pilot circuit of that carb. Another "not so pleasant" possibility is oil passages for that cylinder. More likely is a lean issue, though.

If the temps DON'T even out at higher RPMs, then I'd suspect intake leak or oil passages. Again, intake leak is much more likely!

[spyderrocs]

The hole in the pilot screw cover on that one carb was larger than the rest. I richened it by 1/4 turn and went riding. The temps went down by 50 degrees so i think if i give it another 1/4 turn i might be alset. I'll just give the plugs a look after.

[flyingace]

ok took it out for 15 minutes or so. Header temps evened out a little bit, number 1, 2, 4 were around 180 all within about 20 degrees of each other. Number 3 was still extremely high at around 250. should i be concerned? Time for a sync?

I've never heard of taking header pipe temps as a diagnostic tool. Is it even valid? Your center cylinders will always run hotter than the outsides. Maybe 250 is correct and you have one inside pipe that's too cold. Maybe one header pipe is thinner than the others. Are there factory header pipe temp values? If there are, let us know.

I would check the synch, look at the plugs and listen to the engine. And if it ain't broke, don't fix it.

[Road_Clam]

My headers were way different temps to the touch, so i measured them with a infred temp gun. Numbers one and two were about 100+/- number 3 was 250 and number 4 was 150. This is in farenheight after idling for 2 minutes or so. Obviously this shouldnt be right, so what could it be jetting? Plugs?

If you are taking your reading after some extended engine idle time, your carbs need to be cleaned, sounds like your pilot jets are clogged. My exhaust header temps would measure about 160F with only about a 5 degree variance.