My header pipes have allways been a nice golden colol for 1,000's of miles. Imediately after the last valve adjustment my right side header started turning blue. Just a little at first after a 200 mile fairly hard ride but more & more until a good 30 mile stint with some friends at around 90 MPH & now it is WAY blue & the Left is still gold. I assumed It was a goof with the last adjustment but I rechecked & rechecked & it's not out of spec. I'm running a Boyer E.I. With a single Mikuni so can anyone tell me what to check? Thanks.
Unlogical excessive heat on right side??
- Thread starter gtsun
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Tiny airleak on that side of the manifold.?
Weak spark, (coil or plug) would mean poor burning, so more likely
to be cooler on that side.
Are you sure the Carb was rich enough at 3/4 throttle before this ride.
I.E. have you ridden it like that before ?,.. Sustained 3/4 throttle.
You might have a weak spark on the other side, that has shown up as one hot pipe.
AC.
Weak spark, (coil or plug) would mean poor burning, so more likely
to be cooler on that side.
Are you sure the Carb was rich enough at 3/4 throttle before this ride.
I.E. have you ridden it like that before ?,.. Sustained 3/4 throttle.
You might have a weak spark on the other side, that has shown up as one hot pipe.
AC.
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Some possibilities intake balance tube fell of the right intake manifold, loose float bowl on right carb, stuck float on right carb, needle clip fell off the jet needle right carb, air leak between carb and manifold, o-ring on right carb broken or missing, cracked heat insulator. 
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Single Mik, illf8.
Good thinking AussieC My brain due to working double night shifts w / 3 hrs sleep a day didn't even think about a air leak. That is a good thought. Just re- checked the valve adjustments so will now look for air leaks. Sorry, guess I should try to get some sleep before bothering you guys with this stuff.
Probably the carb, singular, though.
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gtsun said:
First clue - started after valve adjustment.
Suggest you have a look and see if the exhuast valve still has proper lash. Could be it is not seating and is allowing blow by.
Ya I think it was valve adjustment too because it turned blue right after I adjusted them withing 50 miles. I rechecked & it was a bit loose but Im going to check my timing chain anyway, Im overdue for that. Hope the bushing is ok I just don't have time or $ to deal with that right now & I want to ride.
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I would have expected "too tight" to be the problem, not "a little loose".
How far out was the valve adjustment when you first made the adjustments? If there were no radical changes then I would be looking elsewhere. Has there been any other noticeable performance changes after the valve adjustments that can give you a clue. A cracked, broken or displaced manifold balance tube is usually very apparent and usually impacts both cylinders. Cam chain tension is a good one to check.
How far out was the valve adjustment when you first made the adjustments? If there were no radical changes then I would be looking elsewhere. Has there been any other noticeable performance changes after the valve adjustments that can give you a clue. A cracked, broken or displaced manifold balance tube is usually very apparent and usually impacts both cylinders. Cam chain tension is a good one to check.
I never got back with what I think was the true reason this happened. I was confused because it happened so fast just after a valve check that showed if anything they were loose not tight. Then I noticed after putting the tank back on that the new Targon fuel line on the main side was KINcked just before entering the single Mikuni. I think it was cutting off the fuel supply and the Right cylinder was running lean. Changed the line & all seems (Seems) well.
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Smacking head on magical physics solution that slow fuel flow in a single carb only affected one side to notice. Very interesting attention getter to me for snooping into the manifold casting finish or something to bias the mixture flow splitting un- equally. If something caused a swirl that might cause deflection into one side.
I'm not suggesting only the Right side was lean,, just that it was worse. I rode a good 100 miles today after no changes but rechecking the Valves & the pipe is not turning blue. ( I did clean it first blue off etc) haven't checked cam chain cuz Im still waiting for the tool.
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gtsun said:
When you accidently pushed the CARB SIDEWAYSISH ?
:mrgreen: Those nasty Triumph UNIT 650s with a single carb , had available ' Tapered ' ( across ) intake / carb insulators , to angle the carb to
get ' appropriate ' mixture to ea. cylinder . BIAS in fact . Despite being a symetrical 360 Deg. Twin . We turned the spacer opposite in the Southern Hemisphere .
Id try plug readings . If you seperate mixture & ignition readings . Also check it IS exactly the same degrees fireing on Ea side , just in case , maybe , perhaps .
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