95 rmx issue

[argclh6670]

Today, 01:36 PM
hey guys, I have an issue with my rmx that's drivng me crazy. what its doing is fouling plugs...a little history, I just recently rebuilt top and lower end. ran heat cycles to break in....

before the rebuild, the bike had started missing at 1/4 throttle the ride before. I didn't address it at that time due to the topend being 3 seasons old, I wanted to freshen it up. so, when I pulled it apart I decided to replate cyl (visibly worn) and what the heck I figured do the bottom too. good thing....one of the main bearings showed obvious wear in the inner race.

back to story, its fouled 4 plugs in last 2 hours of riding/testing bike. it acts like it running rich (missing) around 1/4 throttle (same as before rebuild but way worse) but it idles well as is very snappy from idle. ive cleaned carb, set float level, rejetted numerous times, 3-4 times within that 2 hours of testing thinking its all a carb prob. after last go around with carb/jetting I got the bike running pretty good, just a slight hesitation.

pulled back up to truck, gave it a quick rev and hold of the throttle and it starts missing like its loading up and then dies....kick a few times, nothing. swap plug, starts right up.

so now im thinking its electrical?? so I test coil, wire and plug cap per manual. coil and wire spec out, cant get any reading from cap. so I pick up another rplug cap, test it off the bike, get a good resistance reading. figure yeah, that has to be attributing to prob!! put it back together, new plug, warm it up, try to run it up the road for a quick test, start accelerating around 1/4 throttle starts blubbering like its loading up and then dies....fouled that plug too!!

so, in your guys opinion, does this sound like possibly an ignition prob? I currently have the ignition components out, as I am testing coil again, stator and tryn to do the same with cdi as per manual but having issues with getting readings.
95

[6 Riders]

Sounds like a fuel problem. Check the reeds...scratch that...., replace the reeds and rebuild the carb with a new jet block gasket and needle seat.

[KDXohio]

Ever get this squared away?

[argclh6670]

Ever get this squared away?

yes, I belive so. I haven't gotten out to the trails yet. but if gone up n down the street a couple times. I ended up putting the jd kit in im on blue needle #3 178mj and 42pj...1.5 on as. seems pretty good. trying to get out in morning before work tomorrow. dang swing shift!!! will report back.

[argclh6670]

Well.....i thought i got figured out. I did there for 1 day of riding. With the jd kit it was running real crisp, good off idle response. So i thought i got it whooped....

However, yesterday went back out...rode for about 20 mins. After coming down a hill i got on it coming to a corner noticed it hiccuped upon accelerating. Hit the corner clutched it, brought the front up and boom...it started running as if its loading up.

Revved it a couple times and it no longer revs cleanly and accel sucks. Limped it back to truck and loaded up.

Today pulled carb...recleaned everyrhing, reset/check float level and its still the same.

I was looking at elec connections at coil and the wire that plugs into coul from cdi (white w/blue tracer) about an inch down from connector the insulation on wire is light to dark brown like it got hot. Cdi going bad? Stator or coil?,

Please throw some suggestions as im Sorta frustrated at this point not knowing which way to go on trying to fix.

[KDXohio]

Put a new plug in it that's usually how my dads bike will run right before it fouls the plug pretty much those exact symptoms

[argclh6670]

Put a new plug in it that's usually how my dads bike will run right before it fouls the plug pretty much those exact symptoms

Ill be out tinkering with it today bafore work....i havent swapped plug yet because its brand new with maybe 3 hours on it. I have pulled it to inspect....looked good so i put back in. .ill try the plug first and report back. Thanks for suggestion.

[KDXohio]

No problem my dads got an 85 Yamaha IT200 his bike will foul plugs at random sometimes after 5 minutes or so of running sometimes after 4 hours of running and sometimes it's good all day very strange but he always knows right before it's about to foul because it starts bogging down real bad and eventually if he doesn't keep the throttle wide open it just dies and won't restart.

We went out riding yesterday he put a new plug in the day before and wrote it for 3 hours no problem then three minutes or so after we started it yesterday it fouled the plug an we had to replace it. And we have tried to jet the bike nothing seems to help hopefully that's your problem if not maybe another member on here knows a little bit more about those than I do

[argclh6670]

No problem my dads got an 85 Yamaha IT200 his bike will foul plugs at random sometimes after 5 minutes or so of running sometimes after 4 hours of running and sometimes it's good all day very strange but he always knows right before it's about to foul because it starts bogging down real bad and eventually if he doesn't keep the throttle wide open it just dies and won't restart.

We went out riding yesterday he put a new plug in the day before and wrote it for 3 hours no problem then three minutes or so after we started it yesterday it fouled the plug an we had to replace it. And we have tried to jet the bike nothing seems to help hopefully that's your problem if not maybe another member on here knows a little bit more about those than I do

nope....that didnt have any affect on it. Thanks suggestion thou.

[KDXohio]

I had to re read the thread did you ever check/replace the reeds?

[argclh6670]

I had to re read the thread did you ever check/replace the reeds?

The reeds were replaced one ride before rebuild....so they are new maybe 3 hrs on them. I suppose there is a chance rhat one maybe cracked or something....will check to make sure. I have a new jet block gasket coming also. Ive checked function of float needle thats sealing. Thanks

[KDXohio]

I have a 98 rm250 that ran like @#$% when I bought it because it was rebuilt with an RMX base gasket both bikes list both gaskets on their diagrams not sure what symptoms that would give the RMX. But on the RM it blocked off 2 of the intake ports and the bike had 0 top end power pretty much the opposite of your problem on the other hand its really easy to tell the gaskets wrong once you lay it down so its unlikely.
http://www.kdxrider.net/forums/viewtopi ... 31&t=18236

FMF Jetting recomends:

Main: 168
Pilot: 48
Needle Stock 3rd clip
Air Screw: 1.5

I don't know anything about the JD kits but if you happen to have those jets and the stock needle still it wouldn't hurt to try and see if it improves it or makes it worse otherwise definitely need to rule out reeds, air filter, electrical and mechanical

[argclh6670]

I have a 98 rm250 that ran like @#$% when I bought it because it was rebuilt with an RMX base gasket both bikes list both gaskets on their diagrams not sure what symptoms that would give the RMX. But on the RM it blocked off 2 of the intake ports and the bike had 0 top end power pretty much the opposite of your problem on the other hand its really easy to tell the gaskets wrong once you lay it down so its unlikely.
http://www.kdxrider.net/forums/viewtopi ... 31&t=18236

FMF Jetting recomends:

Main: 168
Pilot: 48
Needle Stock 3rd clip
Air Screw: 1.5

I don't know anything about the JD kits but if you happen to have those jets and the stock needle still it wouldn't hurt to try and see if it improves it or makes it worse otherwise definitely need to rule out reeds, air filter, electrical and mechanical

Yeah I'm going to repull the carb when I get home after work tonight hold the reeds check them out. I still have the original carburetor with all the original jets and everything so I'll throw that back in and retest and see if that takes care of anything. Then I'll report back. Thanks for all your help buddy

[argclh6670]

I have a 98 rm250 that ran like @#$% when I bought it because it was rebuilt with an RMX base gasket both bikes list both gaskets on their diagrams not sure what symptoms that would give the RMX. But on the RM it blocked off 2 of the intake ports and the bike had 0 top end power pretty much the opposite of your problem on the other hand its really easy to tell the gaskets wrong once you lay it down so its unlikely.
http://www.kdxrider.net/forums/viewtopi ... 31&t=18236

FMF Jetting recomends:

Main: 168
Pilot: 48
Needle Stock 3rd clip
Air Screw: 1.5

I don't know anything about the JD kits but if you happen to have those jets and the stock needle still it wouldn't hurt to try and see if it improves it or makes it worse otherwise definitely need to rule out reeds, air filter, electrical and mechanical

Yeah I'm going to repull the carb when I get home after work tonight hold the reeds check them out. I still have the original carburetor with all the original jets and everything so I'll throw that back in and retest and see if that takes care of anything. Then I'll report back. Thanks for all your help buddy

I tried the stock catb with those settings....didnt change anything other than ran alittle richer. As i sat n looked at the bike i thought....could the pv do what im experiencing? I mean the bike ran great then pop...it didnt. So i pulled cover on rt side and low and behold the little bolt holding actuator arm on shaft was just lying there. Guess i never torqued it. So the pv wasnt functional. Havent had a chance to fire it up n see just yet. But will report back.