TRX250R.ORG

Workshop => Engine and Bottom End => Topic started by: Anna Glinn on May 30, 2016, 10:53:33 PM

Title: Abnormal bogging?
Post by: Anna Glinn on May 30, 2016, 10:53:33 PM
Just recently purchased a rather "clean" 89 TRX 250r that runs and sounds just as it should! Got to ride it for the first time this weekend, and had absolutely no problem for the first 2 hours. The throttle responded with no delay, quick to rev, sounded crispy and hit powerband like nothing. Then, out in the pit, it just bogged down and died with no given warning. I thought it blew up! Let it sit for a few seconds, and it started first kick. Compression was still the same. It'd ride around just idling, but if you got on the throttle and asked for more of it it'd just bog down and die. However, it'd start right up like nothing happened after you let it sit. It's like it looses spark, or it isn't receiving fuel. Possibly an electrical or fuel problem? Going to clean out the carb, changed the plug, then having a friend of mine (Who restores 250r's-owns 5) look at it. I've been told it might have something to do with the coil, or possibly needs a new stator? Not really familiar with these quads. Probably will clean out the fuel filter, vent and so on. Any suggestions or thoughts are appreciated!
Title: Abnormal bogging?
Post by: The norm on May 31, 2016, 12:17:17 AM
I would definitely check out your stator. I had a constant bog at around 1/8th throttle that turned out to be the stator. Good luck Loren
Title: Abnormal bogging?
Post by: thesmith87250r on May 31, 2016, 07:39:06 AM
First step is try a new spark plug.  It's the quickest an easiest way to see if ya problem also you should always have a spare when riding just for reason cause when a plug fouls out your day of riding is over or ya get stranded.
Title: Abnormal bogging?
Post by: rablack21 on May 31, 2016, 08:10:34 AM
Yep, I'm thinking electrical as well. If you have the option, start by changing out the coil with a known good coil, and see if the problem goes away. Then try a different cdi; again if this is available to you. If neither one of those fix the problem, there are instructions on how to check the stator with a multimeter in the Clymer manual. Try that as well. Sounds like one of those three to me. BUT before you do that, for piece of mind, try changing the plug and see if the problem persists. The plug is the easiest and cheapest to change. I don't think that is the problem, but for 2 minutes of time, it's worth checking.
Title: Abnormal bogging?
Post by: Anna Glinn on May 31, 2016, 09:02:00 AM
Plug wasn't fouled, but I did replace it. Still boggs and dies down out of random.
Title: Abnormal bogging?
Post by: rablack21 on May 31, 2016, 09:14:29 AM
Quote from: Anna Glinn;67957
Plug wasn't fouled, but I did replace it. Still boggs and dies down out of random.
Sounds like a coil, but I would check all 3 three until you find the problem.
Title: Abnormal bogging?
Post by: Aceman on May 31, 2016, 09:41:54 AM
I always start with the fuel system first, it's easier to troubleshoot and quicker to eliminate if it's not the problem.  Clean the carb, and verify your float height while your in there.  With the hose of the carb, turn the fuel valve on for a few seconds and verify you're getting full flow from the hose.  Verify your gas cap breather isn't plugged creating a vacuum in the tank when your pulling fuel from the tank riding.  If this all checks out, then I'd start looking at electrical.  

I've seen coils start to fail after the quad gets warmed up.  When cool, they'll work, after they warm up they'll start to bog or not spark at all.  I had a stator quit on me last ride, but it worked right up until the quad died like I shut it off.  No bog or anything, it just shut down.  Then I've also seen stators do the same as coils, they work fine when cold, the quad warms up and then the bogging starts.  You let it sit for a while, and then it'll start right back up and then start bogging when it's warm.

The Clymer manual has some resistance checks for ignition components.  When my stator failed, one of the resistance readings was way out of spec.  So it was easy to diagnose.
Title: Abnormal bogging?
Post by: Anna Glinn on May 31, 2016, 09:43:21 AM
Will do! Thank you again!
Title: Abnormal bogging?
Post by: doublej on May 31, 2016, 12:29:16 PM
Check to make sure the c-clip hasn't come off the needle on the slide in your carb.
Title: Abnormal bogging?
Post by: wretched73 on May 31, 2016, 04:54:14 PM
I was chasing issues with my '88 R for longer than I like to admit. (constantly broken down due to electrical or fuel issues) I knew performance was my main goal so the first thing I did was a thorough cleaning of the gas tank, pet cock, fuel lines and carb. Followed by a brand new CR 250 ignition.

Since then I haven't had a single hiccup! I know its an expensive route but I couldn't bring myself to keep screwing around with an ignition system that was inferior to begin with. Others might not agree with my route but after the countless hours I have enjoyed my quad since then, I am glad I spent the money.
Title: Abnormal bogging?
Post by: 250r feign on June 08, 2016, 12:11:29 AM
Have you looked into the carb yet? My friend had a similar problem and we pulled the float bowl we found the main jet had came loose and was just sitting in the bottom so it would just flood out when throttle was applied.
Title: Abnormal bogging?
Post by: Burns363R on June 08, 2016, 03:32:52 PM
C clip on needle, and check your reeds, make sure there not broke.