backfires?

[honda182]

So today I fired up the ole R to take it around the neighborhood. I had just ridden it a few days ago and it ran perfect but today Just as I was hitting the toppend it would backfire. I just installed a cpi rev pipe and I raised mainjett from 195 to a 205 to be on the safe side for now and it ran fine but today it was backfiring. I'm thinking its just a fouled plug because jetting is to rich but I havent had time to skrew with it. But I got to thinking it could be a timing problem because backfire usually doesn't happen when you are on the gas does it? I just want to hear some of your opinions on the subject.

[C-LEIGH RACING]

Old stock ignition could cause it as well, cdi box or wiring harness connection.
Try a 18 to 20 thou plug setting & see if that changes anything.
Neil

[honda182]

Put a new plug in it gapped it to .018 and now it revs harder than it ever has and hasn't backfired since

[blasterandy]

Setting the gap in the pulg is a major adjustment in 2-stroke or 4-stroke engines. When i buy plugs i buy 10-12 and set the gap on all of them before i even put the first one in. Its almost wierd how the smallest things can have the biggest impact on performance. A plug not set right could leave you in last place.
Sry i was just following up. :D

[C-LEIGH RACING]

You would be very surprized to know just how many riders it has been that seized the engine jetting them trying to get a ignition skip out of their engines.
I'm not talking about first timmer kids either, seasoned riders that should know better.
Neil

[machwon]

First things first, try a new spark plug, then the recomendations above. CPI rev pipe, I didn't know they made one for the R!

[honda380]

hi, sorry, im not trying ot steal the thread, but i was just wondering if you could post a little more info on gapping plugs. like bigger/smaller gaps and their effects on the motor. and why it is that way. thanks, i want to try some of this stuff to mine so i can fine tune it. Corey

[C-LEIGH RACING]

Those old 250R ignitions because of the connectors through out the harness being loose & getting bad connection causes the spark to be weak.
Even the mounting points of the ignition system, corrosion between them play a part as well & end up a bad connection.
With a weak spark you need to close the gap up on the plug so it will be easier to jump the gap to the ground strap.
Neil