Forum

[Reg]

Just changed pilot jet for 27.5 as per Scottys suggestion. Brilliant! Even started without enrichment lever. Tickover when warm is now also much more even. Not sure about raising needle, one thing at a time and all that. Thanks lads, what a wealth of knowledge at our fingertips.

[Reg]

Went for a spin today after fitting the bigger pilot jet. What I didn't mention last time I wrote, was that I discovered a split in the carb/tea caddy rubber connector. As a temporary fix I cut a sleeve from an old inner tube and fitted it over the torn connector. The bike started as usual today, but what surprised me was that I was able to knock off the enrichment lever almost immediately. She seemed to warm up much more quickly than before increasing the jet size, and the improvement in slow speed traffic was incredible. Now, I'm wondering if this was ALL due to the richer pilot jet, or had that rubber been split for a very long time without me noticing. If this is the case it just goes to show how important the little details are. I look forward to your valued comments.

[ric]

With a freeflow exhaust fitted and noting the difference a larger pilot jet has made I'd be very tempted to put a 120 main jet and raise the needle by dropping its clip down one notch. If the engine develops a rapid misfire at 1/5 slide open - that's 1/5 between sitting right on the bottom with the idle screw out of the way and the lowest part of the slide level with the top of the carb body - not 1/5 of throttle rotation - and to find this position you'll need to be looking into the carb body before marking the corresponding amount of travel against the throttle grip, then you'll also need to increase the needle jet holder by one size.

[Reg]

Cheers, Ric. That's interesting stuff, very well explained. She's running a 115 main jet as fitted by PO,presumably when sporty exhaust was fitted. I am toying with the idea of fitting one of our hosts pancake type air filters and re-jetting to suit. Not so much to boost performance, more to make use of RH tool box. Torn between doing that or fitting a small tool box on the rear carrier. At least that way I can't screw up what is now a sweetly running motor.

[jefrs]

Carburettors are right 99% of the time for main running but tend to rich at idle. Getting the main running mix is most important on main jet, needle and slide. I don't know which carb you have (i.e may be talking rubbish) but generally drop the idle then raise and then lower the slide on the throttle stop screw until it hunts then raise it half a turn-ish until it doesn't, adjust idle to a nice speed on the air/mix/bypass/idle jet screw whatever thingy. It's a bit of an iterative process, one then the other then the first again until it's right, each time trying to slow it down to a nice even idle. You can go past the sweet spot and have to start over. Fitting a pancake filter should not need the jet changed further.

[Reg]

Thanks Jefrs, but I think I'll leave well enough alone. Bike is starting easily, running nicely and ticking over evenly,(with the occasional blip of the throttle to keep her awake.) However, I shall make a note of the procedure you posted for future use. Cheers.