Back on the road - mostly.

[SiP]

Just wanted to say I'm finally riding again. Snapped plug, bent valve, oil leak etc.. all sorted.
She is missing at idle and idle seems to be too low and has the same miss when coasting at low rpm but pulls well when opened up. Checked and re-ended the spark plug wires so I think I'm going to have to bite the bullet and sort my carbs out - not looking forward to that at all.
Interesting reading the paint thread, I'm going to tackle mine later this year and like TC have very little expierence so I'll be watching that one closely.

[SiP]

An addittion to the previous info is - if I open her up hard and then close off hard, she backfires like a bugger.
When I read my previous post I realised it actually sounds like I know what I'm doing when in fact I was kinda hoping a guru would say "Oh yeah I know what that is!!" - I'm living in hope that will still happen

[TopCatGr58]

Hey SiP,

IF you haven't gotten into your carbs, then you're right, you need to sort them out. Backing off of the throttle with the rpms still high leans out the mixture quite a bit and can cause some popping, but a real backfire can be a cycle of air fuel getting thru the piston cycle without being ignited in the clyinders, and then when the wasted spark hits the unburnt exhaust gases, pow!

You still may have some ignition issues? The 81 only uses the vacuum advance...no cent. adv....built into the TCI, but the timing plate is still rotated, not as much but still does, and so wear on the wires can still occur, so have you checked your pickup coil wires?

Low rpm/throttle actually induces more advance=flexing pu wires more. Higher throttle creates less vacuum "TO THE ADVANCE" and retards it to the MORE OPTIMUM less advanced timing vs. the very advanced timing of cruise load setting. So...hard throttle, lots of fuel/air, but then cut throttle, more vac. adv, flex wires= inducing possible intermmitent spark/miss, and POW backfire!?

Other dissenting O'prom'ions are welcome!!
I did stay at a Holiday Inn last night!
T.C.

[prometheus578]

No, T.C., I can't dissent too much.
I don't clown around much with electrical timing issues like you do. That's your realm, not mine.

same miss when coasting at low rpm

I agree about the lean'ness of the carbs.
Rough idle, and the popping on decelleration points that way.

[SiP]

I'll get into the wires at the weekend - both P/U and advance. The funny thing about the carbs is when I had the head all stripped off the valves and seats were very carboned (not sure if that's a word?) up which I thought indicated a rich mixture. Really there's no way around it in either case, I've got to get into them
Thanks fellas.

PS Got my new 4 - 1 in the post today, so excited about that.