Hi everyone
i have a Yamaha TR1 1984 981cc which i have completely rebuilt.
i am having trouble trying to get the fuel mix correct does any one know what the presets are for the carbs? or can give me settings from their own bikes to give me a starting point,
if it is not possible to get the presets can someone confirm if turning the mixture screw in makes it rich or makes it lean?i have tried using gunsons colortune but im still running rich on number 1 cylinder and lean on number 2.the manual doesnt give any of this info and dont want to damage the engine not after all my hard work
thank you for looking at my post blackman4816

Hi Blackmann,
turning the screws out makes a lean mixture, under normal circumstances 3 turns out on both carbs should work.
The "richness" of no.1 (back) can be caused -besides the fact that carb No. 1 has bigger jets-by some oil coming from the ventilation-hose, or whatever it is called. Another try : close the little vacuum pipes from the intake manifolds and set the petcocks on pri,

Regards Ali

Äh, if i'm not completely crazy, turning the screws OUT makes the mixture RICHER.

I removed the hose that goes from the right side of the front cylinder into the intake hose of the left/rear carburetor.

Colortunes did not work on my TR1, so i bought a gunson gastester.

Bye,
Georg

How did you route the breather hose, Schorsch?*

I was wondering yesterday, if there were enough room to route it to the connector on the frame (behind the rear cylinder on the right, when viewed from atop)

Cheers
Greg

* And would you care to share a picture?

hi
why would you change the hose lines?i tried to reset the mix screws out 3 turns but i just keep getting miss fires,ive set them back to what the were originally,any more help available?
would it be possible for someone who has a tr1 to count their mix settings and i would give that a go.....the gunsons co2 tool is a bit expensive just to use once...
thanks blackman

hi,
I set the mix screws 1 3/4 turns out and the engine runs fine and starts immediately.
Good luck,

Hartmut

Somewhere between 1 and 3 turns out will be the right setting. What exactly is the right setting for your carbs can only be found out with a CO tester. Misfire can also be caused by poor synchronisation of the carbs, so in addition to the expensive CO-tester you will also need a pair of underpressure gauges...

I removed that breather hose because the blow by gas from the engine influences the CO measurement.

Bye,
Georg