91 RMX250 Spooge King - Revisited

Studboy

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#1
We have worked countless hours on the RMX since last times post with no real improvement.

Bike Mods are as follows:
Boyeson Power Reeds
Pro-Circuit Pipe
Answer S/A
RM Head

So far here are things that we have done:
New Topend and gaskets. Double Checked.
New Reeds.
New Right side crank seal.
New gas. Premium, 32:1 Mobil 1.
New plugs.
Cleaned carb 10+ Times. Attempted adjusted float heights and jetted the bike up to 6 sizes leaner on the main with absolutely no difference. Tried the other carb we have for the bike. Maybe a little bit better but not much. Also tried the choke plunger out of the other carb.
New Filter properly oiled.
Repack silencer.
Triple checked everything.
The newest thing: Spent $400 to have a new stator installed and absolutely no difference.

The bike runs like the choke is on. It runs like absolute crap, smokes and spooges like crazy and it doesn't have any response or power. The bike does start on the first kick and idles. The exhaust doesn't smell like tranny oil and we definately do not have a coolant leak.

This bike is driving us crazy. We keep throwing money and time at it and it really isn't funny anymore, we absolutely can not figure it out.

What else could cause this mess? My friend would give you a kidney to know. <IMG alt="" src="http://www.dirtrider.net/forums3/images/smilies/smile.gif" border=0>
 

marcusgunby

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#2
Could be the coil or the black box.You need to borrow a similar bike and transplant parts until it works.We use this method at work as a last ditch attempt.It works.
 

Studboy

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#3
Would a weak spark cause these sorts of problems?&nbsp; When the stator went bad on my dad's LT500 the bike would just sputter and backfire a lot. These bikes are rare around here, I would love to have a transplant bike to work with so I could test the black box.
 
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#4
1) Are you positive the RH crank seal is in the correctly? The manual can be misleading.

2) Clutch side, inboard of the primary drive gear, there is a collar on the crank shaft with an innear-diameter o-ring. If not insterted on the shaft carefully (CW & CCW while pushing inward toward the crank center), the o-ring will dislodge from the machined depression/slot and allow trans. oil through; the shaft has a machined edge which could catch the o-ring on the way in.
 

zero_it

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#5
1. Make certain that your ignition timing is properly set.
2. When you did the top end, did you completely disassemble, de-carbon and clean the power valves? They may be stuck shut due to carbon build up. Also make sure all the linkage is properly hooked up on the power valves. If not, then they will not open. The '91 RMX may have an externally adjustable power valve spring. If so it may be wound too tight and holding the valves closed.
 
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#6
If you don't have an extra brain box to swap, try takeing the spark plug out put the coil on it ground the spark plug to one of the head bolts and have someone crank the engine over, watch for the spark. If you can clearly see the spark and it is consistant(it sparks every time the engine turns over)then it's not your electonics. Also you said you are running your fuel mix at 32:1, unless you are breaking ing your engine that is way to rich and that alone would cause all your problems, so try mixing your fuel at 50:1, that is what I run my 1986 CR250 at and it runs great.
 

Bodge

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#7
It should be fine at 32:1. That would not cause all those problems motofreak.
 
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#9
As crazy as it sounds; since i cannot physically see the bike, i would recc that u rem the pipe, and the airbox.
Leave them off, and try out the bike in your garage.
(The pipe could be faulty/obstructed, and the airbox can be collapsing under a vacuum, when u open the throttle, or someone left a shop rag in the airboot...)
If neither of these help, then verify:
1. piston not installed backwards
2. proper base gasket was used (ie, not obstructing any transfer ports, etc.)
3. your reeds are not installed upside down/incorrectly.

ps---did this bike run when u bought it?