250R backfired??

**Dirtcrasher** · 11-04-2003, 01:09 PM

My 85250R has backfired 2 times out of 25 while trying to start it. Stock fresh top end, stock carb, Boyeseen reeds, FMF silencer with stock exhaust. Everything is fresh and spotless and otherwise seems to run perfect. Any ideas??

Thanks!!

**Lots_Of_Nothing** · 11-04-2003, 04:21 PM

change your spark plug.

let me know how it works.

**Tri-Z Pilot** · 11-04-2003, 05:03 PM

Check your fuel mixture screw too.

**Dirtcrasher** · 11-04-2003, 08:40 PM

Originally Posted by Tri-Z Pilot

Check your fuel mixture screw too.

Well it wouldn't start first kick so I turned it out a bit more - with a 250R I can't hear the difference like I could with a 4 stroke so I don't know where the hell to put the fuel screw!!! I guess your saying it's jetting???

**Tri-Z Pilot** · 11-04-2003, 11:59 PM

If you have had a sudden drop in temperature where you live its likely you have a lean pilot circuit. If your mixture screw is behind the slide of your carb (airbox side), turn it in to richen the mixture. If your mixture screw is in front of your slide (motor side) you turn it out to richen the mixture. Richen it up a bit and see what happens.

**TeCaTe_MaN** · 11-05-2003, 01:04 AM

..............who cares.....it's a backfire

thats all.... :?

**TimSr** · 11-05-2003, 09:12 AM

If its backfiring two out of every 25 times you start it, and you are worrying about it, Id suggest upping your dose of prozac, and switching to decaf.

**Jeb** · 11-05-2003, 10:03 AM

Originally Posted by TimSr

If its backfiring two out of every 25 times you start it, and you are worrying about it, Id suggest upping your dose of prozac, and switching to decaf.

LMAO!

Sorry DirtCrasher ...

**Manny55** · 11-05-2003, 10:51 AM

lol

**Dirtcrasher** · 11-05-2003, 10:56 AM

Originally Posted by TimSr

If its backfiring two out of every 25 times you start it, and you are worrying about it, Id suggest upping your dose of prozac, and switching to decaf.

It was just a question. I haven't owned a 2 stroke in years but when I did they never backfired. Normally one of you might post the possible damage that may occur by an engine backfiring rather than a comment like that.

I though maybe something was wrong with it but I'll take your reponse as "normal operation". Thanks for the help.

**Manny55** · 11-05-2003, 11:09 AM

2 out of 25 times its prolly just a cold start.

**Levithan** · 11-05-2003, 11:32 AM

ROFL @ timsr! geez, talk about wake up joke for the masses!

**TimSr** · 11-05-2003, 02:58 PM

Sorry Dirtcrasher, didnt mean to be insulting. Backfiring is a buildup of fuel that finally decides to ignite, usually from like an intermittent spark that didnt ignite each rotation. Common causes - bad plug boot, bad plug wire, or bad or fouled plug, when it happens a lot, but more often, its simply nothing to worry about, and its caused by the gas buildup you get from kicking something over a few times before it finally fires up.

**Dirtcrasher** · 11-05-2003, 05:46 PM

Originally Posted by TimSr

Sorry Dirtcrasher, didnt mean to be insulting. Backfiring is a buildup of fuel that finally decides to ignite, usually from like an intermittent spark that didnt ignite each rotation. Common causes - bad plug boot, bad plug wire, or bad or fouled plug, when it happens a lot, but more often, its simply nothing to worry about, and its caused by the gas buildup you get from kicking something over a few times before it finally fires up.

The thing is you have had some fantastic posts here and I've learned quite a bit from them - anyhow I was just curious as I am new to this motor. I'm running a bit rich to break it in and have fouled a couple of plugs so that makes more sense. Thank you :-D

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250R backfired??