CARB TUNING AND MANOMETER RESULTS.
Hello all, I'm back! I've been enjoying just riding my bike for a while. The bike runs pretty great, once it gets warmed up, but when you first start it up it runs like crap. It blubbers and misses and pops. But after it warms up it idles perfectly. I know the bike suffers from a lean condition, I have progressively upped my main jets until I am now two sizes up from stock. Doing that has dramatically improved the performance of my bike while making my idle settle down. My air mix screws had been opened up pretty far past spec in order for it to idle properly.
So.....today I dropped my carburetor bowls and installed new pilot jets , 27.5's up from stock 25's.
Immediately after getting the carburetors back together I set the idle mixture screws back to spec and did a dead cylinder run to set the mixture screws again. Here are the results.
Left cylinder went from 2 3/4 turns out to 2 1/4 turns out.
Right cylinder went from 2 turns out to 1 3/4 turns out.
The left cylinder is still set too rich to compensate for a lean condition caused by internal carb body wear that I have documented previously. I will replace the carb body probably this fall.
The right cylinder is getting pretty close to acceptable settings now.
Now on to my manometer. This was a bit of a surprise to me. I took great pains to bench sync the carbs as accurately as possible. When I hooked up my manometer and started the bike this was the result. On my yardstick manometer the left cylinder was pulling much harder, up around the 10 inch mark, and the right cylinder was pulling way down at the 30 inch mark.
After adjusting the sync screw MAYBE 1/8 of a turn , here it is now , nice and level.
Then , just to be sure, I checked the individual carbs one more time using the dead cylinder method. No changes were necessary.
The engine feels smoother after setting the sync. By this time it was 105 degrees out and too hot for a test ride. I'll have it out tomorrow early and see if it feels any better. I'll post a little follow up.
On an unrelated note I picked up a set of offset box end wrenches from good old Harbor Freight. They aren't the prettiest wrenches but the will do the job and 5Twins was right, they're just perfect for certain jobs!
I'll check back in tomorrow, after taking the bike for a run. See ya then
Bob