UK Bobber Build thread

Hi Carbon, I have just come from said Pub :) its only a few hundred yards from my house :)
Thanks John!
So, today I went back to basics with the jetting. I returned the BS34s to 42.5 pilots and 132.5 mains. The bike runs better than ever. The timing is now spot on and I am getting 70mph and probably around 45 mpg. Still think I'll up the jets and lower a needle but that'll be a bit tinkering. Had the bike start sputtering and cut out on me this afternoon. Left for 5 mins and ran then stopped. Too a few minutes to work out I have a dodgy ignition switch :)
Enjoying riding it though - lots of fun!
 
Good to hear you got some time on your bike Paul. Well, don't tell me your switch is crap.I hope mine is a good one. If it's good enough for a tractor, it should be good enough for my bike.:laugh:
 
Hi John, yeah it is a bit crap to be honest. It has two positions and the one I had it wired to failed if the key was waggled about! So, I have wired it to the first position which seems OK but Ill have to buy a new switch ASAP.
 
Yeah Lol :)

A little bit more done on the carbs yesterday. Went one up on the pilots and left the mains as stock 132.5. Perhaps a little rich now on the pilot circuit but little or no break up at the top end. I think further tweaking is going to require the the Canadian needles. Ill dial the mixture screws back in properly this weekend and see where i get to. Got a new ignition switch ordered as on closer inspection the one I had purchased (not cheap I might add) has basically suffered from vibration and shook its internals about, resulting in an unreliable connection :(
 
Just noticed on cold start up that I am getting a little blue smoke for 30 seconds or so from the left pipe. Popped the exhaust off and carbs and wiped down the valve stems. Left it overnight, and there was no oil on the stems, so that made methink its not valve stem seals (they were replaced in any case). Popped the tank off and re-torqued the head. the bike has done 150 miles and the chrome nuts certainly needed tightening. Torqued to 26 ft/lb then to 30 ft/lb (as recommended by a few people on here). Started it up and still had a bit smoke on, then cleared away. Plugs are oily but then clear up straight away and look perfect after a run.

I am suspecting either, rings not seated or head gasket issue - thoughts please?
 
Dang Paul, sorry to hear that you've got some issues. I would think the smoke was from the head gasket considering that it cleared up after a re torque.:thumbsup:
 
Yeah, a bit of a pain but thats the joys of building bikes :)
Worst case scenario, I pull the engine replace the rings and pop it back in - it'll keep me out of the pub :)
Quite annoyed with myself I didnt do the rings in the first place but you live and learn!
 
Hey Paul, got an old trick to reseat rings, if you're game.

On a cool morning, start the bike and just 'nail' it, full throttle, up to about 70-80mph. Pull-in clutch, kill the engine, coast (no brakes - you want the cooling), pull off to side of road, park. Wait till engine cools (5-10 minutes). Repeat going back. Then ride normal break-in. If it works, rings seat and smoking stops after about 5 miles.

Adjust the above numeric values to your country's imperialistic furlong by fortnight system...
 

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