Help! Baja soon. Engine problems!

OK, so we've spent way too much money on this bike for Baja and something took a dump on us last weekend. We've spent hours trying to trace it out with NO success. Hopefully someone here has some insight. We're kinda new to XR650s.

Engine releted Mods:

Ricky Stator 250 watt stator w/ voltage regulator.

Honda Power-up kit

White Bros E2 pipe

172 Main Jet, 65 Pilot Jet, stock needle position

EVERYTHING else stock

Bike was running GREAT with all the above mods. 200 miles or so with all the mods in place.

THEN... las weekend it started running rough. REALLY Hard starting (but it will start sometimes). Really crappy sounding engine, popping and backfiring, won't idle. We can keep it running, although very poor. Bad rattly, loud, nasty. It's not an intermittent, it's done nothing but run bad since this started.

At first we were thinking electrical, but we have looked at every wire, and they're all connected well as far as we can see.

Then we thought fuel, but we've cleaned the carb twice and it has run fine with the jetting it has.

Could it be a stator failing??

I'm frustrated!!

you said that the connections were checked out, did you also check them out with a meter?

We have used an electrical tester, not a real good one mind you, and it seems like we're getting plenty of juice. The headlight lights up bright when we're kicking it and when we pull the plug and test for spark, the spark looks strong.

Back to a fuel issue? ... but how does that make sense?

We can't even get it fired up now.

Trying to salvage a practice ride tomorrow.

Pulling an all-nighter...

AAArrgghh.

check the smog block off kit or any other place there can be leaks....

Valve adjustment, plug for intake vacuum hose for smog pump fell off, you are running way to lean pilot jet, and to lean a main jet for the lower elevation. should be 68s or 70s with a 175~178 main, three of the bikes I worked on last year before the Baja 250 had valve clearance that was way to tight. Look at these things first.

garage.php?do=viewattachment&attachmentid=971

All About the XR650R

http://xr650r.borynack.com/

If we're getting good spark at the plug and the light is working, can we eliminate electrical? Is it possible for the timing to be off on these bikes?

It still won't start- not even close. It started two hours ago .

:ride:

The smog pump plug seems to be in place. It's the deal right between the two exhause outlets on the front of the cylinder, right? Can't see anywhere else there could be leaks.

Good news is we got it started again. It will only start and run with the choke full on, and when it is running it's running rough and requires aggressive blipping of the throttle to keep it going. As soon as we let off the throttle or even hold it steady for a few seconds, it dies.

OK, so we've spent way too much money on this bike for Baja and something took a dump on us last weekend. We've spent hours trying to trace it out with NO success. Hopefully someone here has some insight. We're kinda new to XR650s.

Engine releted Mods:

Ricky Stator 250 watt stator w/ voltage regulator.

Honda Power-up kit

White Bros E2 pipe

172 Main Jet, 65 Pilot Jet, stock needle position

EVERYTHING else stock

THEN... last weekend it started running rough.

Ok... a little more info here might help. Were you just cruising along and it started being bitchy or did you put in some gas and then it started its bad behavior. You need to go back to what you were doing just before these symptoms started.

My guess. Ignition control module is damaged. Check the plug pins for signs of arcing. Or if you can borrow one to try out.

Of course you have checked to make sure there is lots of slack in the decompresser cable so we can rule that out.

I can only tell you what I would try, remove the air filter, get a spray bottle of gas and spray (a mist) in the carb while running and see if it helps (be careful of backfires) if it's fuel related it should run much better when spraying fuel in. If it don't help then it's electrical or timing related. If it's electrical retrace your steps check the stator wires in the case first. my 2 cents

Sounds like a freaked out ignition issue (timing, module, coil, crank sensor, etc), if there's anyway to source known working pieces, try them one at a time.

One other thing, I had a used YZ400F once that acted a lot like that soon after I got it. I couldn't figure it out and had it at the shop a couple of times. They'd clean the carb and put a new plug in and it would run decent when I'd go pick it up, a few rides later it would be crap again. Finally figured out one of the cams had either jumped a tooth or been set wrong after a valve adjust. Can't remember if it was exhaust or intake but it was really hard to diagnose and ran a lot like you describe. Might check your cam timing just to be sure.

good luck

look for a vacuum leak, spraying WD-40 around carb and manifold bases, etc ... if engine speeds up while spraying, you found your leak ,,, :ride:

Don't forget base engine items. I say this because if u did stator work and nut is loose on the crank shaft u might have an interm out of time engine. This would be especially true if you can hear it sputter through exhaust and then through intake. I have seen this happen on 650 Dakars. Best of luck!

Sounds electrical.

Drop the RS stator out and reinstall the oem.

I think you'll find crossed wires somewhere.

Is it a dual system? (AC and DC?)

Thanks for all the advice, guys. It gave us a lot of things to try. I feel like I learned a heck of a lot about the XR650 in one day.

It's FIXED!!

We figured it out. Here's what happened: When we put the new Ricky Stator in there, the rubber piece that acts as a seal where the wires come out of the case was a poor fit. It was not at all water tight and when the bike was ridden through a creek crossing, the case got a bunch of water in it. That began shorting out the stator and made the bike run like crap- backfiring and all.

So when the bike got back to camp, everyone was giving their $.02 on what was wrong and there were as many as 5 know-it-alls working on the bike (BAAAAD idea :banana: ). The carb was torn off and cleaned, and then when the carb was reinstalled, someone slipped a carb vent hose onto a rear engine vent (part of the original smog setup, I think). That cut off that vent line causing the carb not to work properly. Once we found that and disconnected it, the bike started running like a champ!

So the perplexing part (and what we didn't know) was that there were TWO issues going on, each giving different symptoms.

Whew!!! :ride:

The last thiing we wanted going into Baja was reliability issues with the bike.

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