Blue Chrome

[Lucky_Lou]

Well the service finished not much work on so a blast out, did about 120 miles first 50 motorway steady 70/80 then some roads over the moors home.I noticed my left down pipe was alot "bluer" than the right having polished them up before i went, would this indicate its running hotter on that side ?? your collective thoughts welcome
Lou

[Barry]

I noticed my left down pipe was alot "bluer" than the right having polished them up before i went, would this indicate its running hotter on that side ?? your collective thoughts welcome

Bluer means hotter question is why was it hotter.

Grossley retarded ignition timing on the hot cylinder would do it - not really a possibility though with a bean can which should only have 1 or 2 Deg difference side to side.

More likely a weak mixture on the hot side. Leaner means hotter exhaust gas temperature within the normal range of mixtures strengths although it's not linear as the temperature eventually goes down again at extreme weakness.

Extreme richness if unburnt fuel gets to burn in the exhaust could also be a cause but this would only be likely at idle otherwise the engine wouldn't be running right.

Had a look at the plugs Lou ?

[Justin B.]

Could also indicate an intake air-leak between carb and head which would effectively lean out the mixture a bit...

[nhmaf]

+1 to both / all of the above.. (or is that +2)??

[Lucky_Lou]

The carbs seem alright tick over is steady but i will be balancing them next week before i go down to Wootton Bassett, the plugs are a nice "biscuit" colour i do have a new set to fit though.
It may be time to change the rubbers to the head as far as i can tell they are the original ones, but i had no problem setting them up at mid range revs  last time i balanced them,  i think i will check the needle position just in case i cocked up refitting them at different levels
Lou

[Dizerens5]

Some multimeters have a temperature probe. Not expensive - see Vehicle Wiring Products cat. And Frost sell stick-on tapes which record max temp reached. Also not expensive. I've sometimes been surprised at the difference in temp between left and right cylinder heads!

[Rob Valdez 79 R65]

It may be time to change the rubbers to the head as far as i can tell they are the original ones, but i had no problem setting them up at mid range revs  last time i balanced them
Lou

Just spray something with ether in it (starter fluid) on them while the bike is running.
If the revs increase, they are leaking.

[montmil]

If I recall, your R65 has points as the ignition trigger rather than the Hall sensor. Ain't that right, Lou?

I have read that there can be wear on the point system cam that will show up as a "stutter" or double image when the strobe hits the timing marks. In other words, your jugs could be firing at two different timing settings thereby creating an uneven exhaust temperature leading to the hotter exhaust one one side.

The Airheads will tolerate a relatively wide variance in timing without undue harm. Just quit standing in front of Gertie and looking at both jugs and her tassles at the same time.

Monte