backfiring.

[10 inch Terror]

Hi all, RB250 with a cyclone fitted. When the revs are up it splutters and backfires. My son in law has been using it and he described the problem as it jumping out of gear. I followed him today in my van and actually saw flames inside the endcan when he was giving it some throttle. Having asked the question on here re kangarooing in 5th I'm now sure it's not gearbox related. I'm now thinking it's something electrical breaking down under load? Any pointers where to start looking would be most helpful. Thanks in advance Pete.

[Daggs]

The only time I've had that problem, it turned out to be the CDi.

[10 inch Terror]

The only time I've had that problem, it turned out to be the CDi.

I'm thinking along those lines too.

[holty]

i would try a new plug, then a cdi that you know works, if no joy check stator, could be a dry joint or a bad connection, or a wire shorting, check the stator wires where the metal clip holds them away from the flywheel, could have worn through the insulation, and shorting out, i hate these kind of faults, could be many things, your going to have check a few things out, good luck.

[Adam_Winstone]

Static ignition or advance retard? If advance/retard, is this functioning correctly?

I've known a couple of bikes to have odd timing issues at some rev ranges but not others, which has been rectified by getting the pickup height right (as per packing pieces now included in with BGM stators).

Adam

[10 inch Terror]

Hi all, I've just changed the CDI, HT lead and cap for brand new items. I've been out along a decent A road up to 65-70 and it's still backfiring. It starts and runs fine in low rpm. I don't actually know what stator is in there as the engine was built for me. The more miles it does, more things are wearing out very prematurely, due to poor quality parts. I think I'll have to whip the flywheel off and have a look what's in there. It was supposed to be supplied with a BGM, or similar quality stator. I have doubts though going on what other poor quality parts are fitted elsewhere. Thanks guys, I'll report back soon.

[ForemanBob]

It was supposed to be supplied with a BGM, or similar quality stator. .

I've had pickups fail on 2 BGM stators giving funny results... Replaced them with Ducati pickups (easy change 1 screw and 1 soldered connection) and all good since then.

[10 inch Terror]

I have a spare SIL stator that I got from MB. It's never been used so I'll fit that and see how I go. Thanks for your help.

[10 inch Terror]

Hi all, I've changed the Cdi, ht lead and cap, plug and stator and it's still backfiring. Could it be the ignition switch? I'm running out of ideas here.

[drunkmunkey6969]

Have a read of the 'pickup alignment' section of this, it might help: http://www.scootering.com/never-break-d ... a-repairs/


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