Anyone have any thoughts on the following please ? My 1982 PE 250 twinshock was running like a dog when I bought it last year. I've stripped the carby, and the jetting and all other bits and pieces were standard according to spec for a PE 250 X but in bad shape. I've Replaced the needle which was bent, checked out the nedle jet ( OK ), and reset the float level.
It rides Much better now, but sounds and feels as though the timing is late. Pulled the rotor off and according to X series specs the timing is actually a few degrees early. The system is iffy ( rotate the backing plate until the hold down bolts are centred in the slots and nail it at that. )
Are X specs OK for these very late twinshock PE's ? On my bike the timing has been set with a score mark on the backing plate lining up with a mark on a ' spare ' support lug ( with no hold down bolt ) in the crankcase. This setting is more advanced than if set by centering up the slots under the bolt heads.
Are there specs available anywhere which would give a figure for static timing, or maybe timing at a specified idle speed, which could be checked with a timing light ?
Is there any advantage in running a small variation from standard timing ? Bike is used for what might be termed Private Enduro.
The mixture is a fraction rich right thro the range, but is very close. Fuel is Shell premium unleaded ( not a good idea according to recent Forum comments ), and Shell Advance 2S oil at 25 : 1, ( recommended is 20 : 1 ) and ( just lately ) with 0.8% of Nulon octane enhancer.
I reckon I can fine tune the mixture setting by running it closer to the recommended 20:1, but what % of extra oil ( less fuel ) is roughly equiv to a drop from 280 to 270 Main jet, and does Octane enhancer also have an effect on carby settings for correct mixture ?
Cheers,
T250.