hydrocarbons excessive fail

[Aidan]

yes instant effect, a small air leak is significant on the intake system, it's all about that perfect fuel/air ratio
distance has nothing to do with it
you should change the oil and filters regularly imho, you should use it more too

[xpress]

thanks for that bit of experience there. yes I should use it more!

sometimes on two stroke bikes if plugs are midway through their cycle you have to adjust the mix down, or if it's cooler or at altitude mix needs to be changed. would it be advisable to adjust the carb fuel mixture as the spark service items wear?

[kevtherev]

No
The adjustable mixture is idle speed
After that your on main jets..which you cannot tat with
Plug colour is only worth noting after a high speed run of over ten mins
Killing the engine and taking the plug out
This will tell you if the jets are worn.
Mixture should be set by a gas analyser.. Not guess work with plugs

[xpress]

strange. what you say makes sense but in the haynes book of lies it says that the mix screw is for the whole rev range. no pun intended. if I have been running with the air leak on the carb for a little while I suspect the plugs are leaned out went too hot and shot and need changing anyway. what do you think rev?

ok so masterplan is... change plugs and et cetera. try and find another mann filter and some mineral oil. then ride the mixture screw while the mot man smiles, rubs his hands together and counts down to another 40 quid! Don't forget they're supposed to give you another pop with raised rev speed to half rev range.

I agree on gas analyser as opposed to plugs check. I so need a gunson. will get a gastester.

[kevtherev]

strange. what you say makes sense but in the haynes book of lies it says that the mix screw is for the whole rev range. no pun intended. if I have been running with the air leak on the carb for a little while I suspect the plugs are leaned out went too hot and shot and need changing anyway. what do you think rev?

ok so masterplan is... change plugs and et cetera. try and find another mann filter and some mineral oil. then ride the mixture screw while the mot man smiles, rubs his hands together and counts down to another 40 quid! Don't forget they're supposed to give you another pop with raised rev speed to half rev range.

I agree on gas analyser as opposed to plugs check. I so need a gunson. will get a gastester.

Your last mot should have the gas test results.
It should be handed to you
The mixture screw is an air bleed..not fuel..that's set in a jet.

[xpress]

guess what. he didn't give me the gas test results. I love the guy.

[paul66beetle]

how easy is it to tune without a gas analyser?

I think Gerald Dale motorsport struggled tuning mine because of the airleaks. Since then I have replaced most if not all of the possible leaking pipes and hoses. Last MOT said it was still running lean but it passed. I would like to see if I can improve it a little.

[kevtherev]

I would say impossible to be accurate
But any MOT or good garage will have one.
All you need is for them to set it up.
Engine up to temp
Then you can twiddle your air bleed screw and idle speed crew yourself
I doubt it'll cost much
But you were right to remove any leaks first.

[xpress]

i am so glad my favourite band is:

gunson roses.

[paul66beetle]

i am so glad my favourite band is:

gunson roses.

I have an old Gunson colourtune in the garage somewhere, not sure how it would compare to modern equipment?

[paul66beetle]

This is what I have kicking about...never used it

http://www.ebay.co.uk/itm/GUNSONS-DIGIT ... 4610a44466" onclick="window.open(this.href);return false;

[xpress]

computer says no.

[paul66beetle]

computer says no.

That sounds not good?

[xpress]

will change service items and once I receive my certificate in twiddling then I am sure I will get my certificate of vanology?!

[paul66beetle]

Have you tried leak detection spray, to see if you have a leak?