AberdeenBikers

having probs starting my bike takes ages to catch then backfires when it does, occasional backfire when running. spark plugs been replace bout a month ago. idle doesnt stay the same either, any ideas?

If the problem started since installation of the new plug, then it could well be the plug, or possibly the HT lead not fitted correctly or damaged during the installation.

The backfire is probably caused by too much fuel building up before the bike fires.

Note that most vehicles do not need throttle to start these days, doing so can flood and cause problems. If an engine does become flooded, open the throttle fully (to reduce manifold pressure) this will actually lower the fuel/air ratio with a standard carburation set up. Keep the throttle open fully do not keep yanking it open, because if you have an accelerator pump within the carb it will simply squirt more fuel in with each yank. Turn the engine over with the starter and if it catches, back off to nothing and catch it on the choke. If that doesn't work you have to either wait a long while or take the plug out and dry things off.

When I had mine it was a pain in the erse to start untill I realised the reg/rec wasn't earthed properly this was causing a poor spark giving a rough idle and backfiring on startup the head lights dipped a fair bit too when idling cause it wasn't charging properly.
Its on the right hand side of the rear subframe as you look towards the handle bars from the back (you'll need to get the plastics off to get at it), make sure the eath wire is touching the metal base plate between the reg and the subframe and isn't just on between the reg and the bolt head.
check its charging properly at the battery first though with a volt meter should be putting out about 14V when running

Ditto ..

Mine had problems starting when the reg/rect unit went tits up and the battery got screwed. Even went through the hastle of changing out the starter before I found the source of the problem.

Big Kneed Al (master of the emergency stop & "stand up" comedian).

Gazza wrote:Note that most vehicles do not need throttle to start these days, doing so can flood and cause problems. If an engine does become flooded, open the throttle fully (to reduce manifold pressure) this will actually lower the fuel/air ratio with a standard carburation set up. Keep the throttle open fully do not keep yanking it open, because if you have an accelerator pump within the carb it will simply squirt more fuel in with each yank. Turn the engine over with the starter and if it catches, back off to nothing and catch it on the choke.

Naaa, just keep the throttle pinned once it fires up.....

....got to let these things know who is in charge

Who needs the choke when you have a rev limiter!

Who needs a hammer when you can smash it from the inside out

Big Kneed Al (master of the emergency stop & "stand up" comedian) ( Super Nanny ) wrote:Who needs the choke when you have a rev limiter!

Exactly, why else would they fit one

thanks a lot folks, my battery died a wee while ago as well just like that so it sounds like it could be the earth will check it out. thanks again

I found that mine needed a reg/rec, they have a habit of cooking themselves, hopefuly it will be an earth.

I also find that if you use any gas at all when starting, it will flood when cold, no gas, full choke, then catch it with a wee touch of revs as it fires, works every time.

chaos wrote: I also find that if you use any gas at all when starting, it will flood when cold, no gas, full choke, then catch it with a wee touch of revs as it fires, works every time.

yea no gas for mine 2 but if i use any choke at all before it catches it just floods! funny b*ggers bikes eh?

Sounds like you need some of this. Only available in Australia unfortunately.....