Thanks again Mr SPRIDDLER. Such a wealth of knowledge. Yes, I'm aware of useage of throttle position vs carb pilot, needle and main usage, and it seems that luckily, i've done my first 30 miles this time round with no more than 1/2 throttle, so very little use of the main jet, meaning I've most likely saved the engine from overheating. I can now use more than half throttle with confidence that it's getting enough fuel so will not run hot due to lean mixture.
As for your comments on the timing, thank you for clarification. And yes, that is the method I use, however, I must admit, I've never thought of adjusting timing via the bottom timing sprocket. This makes complete sense, and I'll be doing that from now on, as I often need 2 or 3 goes to get my timing right due to the mag sprocket moving upon tightening. THANK YOU FOR THAT TIP!
That said, I may need to work on some other timing disc method, for at least my knowledge, and, my new Matchless Whisperer, says the compy's with hotter cams require a bit more precise timing.
Cheers!
Marty
SPRIDDLER wrote:Well you do seem to be making progress. Personally (other opinions are available) I wouldn't get too hung up on relatively minor main jet or slide variations vs various bits of documentation as these can be tweaked for best performance once you are satisfied vis-Ã -vis the smoke and overheating issues. It's worth bearing in mind that up to about 1/3rd throttle opening th'engine is being supplied mostly by the Pilot jet, then Pilot jet and slide/needle up to half throttle, then slide/needle and main jet up to full throttle. Much of the time most of us are running around locally at half throttle or less therefore the Pilot jet setting is important.
You may find this carb tuning guide useful/interesting:
http://www.hitchcocksmotorcycles.com/mo ... to-tune-up
As far as ignition timing goes I have only ever used the 'stick in the hole' approach which I find entirely satisfactory and far more straightforward than faffing about with a timing disc and which isn't as easy to set up on our h/weight singles. On a minor point, with modern fuels and on touring engines I time to 7/16" BTDC at full advance (set points gap first) but to be quite honest if you time to 1/2" BTDC you can fiddle a tad with the A/R lever and experiment whilst out on a ride. My ignition is on full advance when the cable is tight (i.e. pulled) so when I set the timing on an unfamiliar bike I leave a bit of movement (1/4" of cable) available at the handlebar lever so that I have a bit of adjustment to play with whilst out on the road. On some magnetos the ignition will be fully advanced when the cable is slack. There is frequently confusion with new owners as to which way to move the lever for advance and retard. I assume you must have this clear in your mind........?
Not wishing to bore you but when setting the timing it's best to loosen the lower mag chain sprocket to make adjustments rather than the upper sprocket on the mag shaft since it's easier to prevent the lower sprocket from moving when you tighten the sprocket nut.
High tech wire coat hanger timing probe:
CIMG4398_zps5b2c3873 (240x180) (240x180) (240x180) (240x180).jpg
CIMG4402 (480x360).jpg