Viper only getting 8000 RPM's

Well I took my sled out tonight and I didn't really get consistent results. It would pull 8500rpms sometimes, but not every time. It didn't seem to change the more I rode it when the engine got hot. The temp was cooler tonight and the snow was better, maybe that's why it didn't do exactly the same thing as last night. On the steepest part of my field when it hit 8500rpm it would drop back to 8000 just before I had to let off at the top. Then on the flatter top part of the field it would sometimes hit 8500 rpm and sometimes only 8000rpm. I tried it with the hand and thumb warmers on and off and it didn't seem to make any difference. I would've unplugged the headlight, but by the time I get home its dark out. It's very encouraging to even hit 8500rpm since it hasn't done that since I've owned it. So I'm not sure if this is a clutching problem of a stator issue. It sounds like what some people have these symptoms with either. I wish we had some snow so I could do a proper test instead of these short WOT runs, but I guess this is better than nothing.
 

mine is doing the same exact thing. What wires do i check on the stator and what is spec? does the engine have to be warm to get correct readings also?
 
Guys, I know this stuff is frustrating. It just takes a long time to do checks when all you have to correspond is a post on a website. It takes days to do something that would only take a few minutes because of posting and waiting for answers then replys back. So hang in there.

when you ohm out a stator the checks are done at like 68 degrees F.
so since its winter out, I would say have the engine warmed up and then check the stator at the plug over by the recoil. The resistance value is supposed to be .36-.44 ohms on the 3 white wires.

I will say a ohm check is ok, but I have had stators show good on ohm check range that didnt charge enough. I dont like to base a bad stator diagnosis with just a ohm meter, I will start unplugging items to see if it gets better running and then go from there. I have seen alot of times if the sled is harder to start after you ride it for awhile the staotr is on the way out, low rpm would also be a clue, as the biggest draw is wfo!

In all this thread, I am just trying to find out information from both of you guys as to whats wrong without spending your money for you and not solve the issue thats all.
 
Yeah I hear you Mr Viper its hard to diagnose a problem like this over some posts over the internet and I really do appreciate all the help you've giving me so far. I'm leaning toward it looking like the stator may be at fault. My resistance was off on the stator (.7 ohms ) but I've had a mechanic say like you that an ohm meter reading that's out of spec doesn't necessarily mean that its bad. Is .3 ohms enough to call it bad? That's the tricky thing about these things. Another you said struck a bell was that when I did go on my one ride before we lost our snow was when we stopped my sled didn't fire back up like it should've ( 4-6 pulls ). I think my best thing to do is try my brothers clutches Saturday and see what happens. If the problems go away then I'll have to get the clutches rebuilt, if its still there it looks like the stator is bad. At least I'm not losing riding time since we don't have snow anyways. One good thing about this is I'm learning a lot about my machine and how to work on it. So thanx again to everyone who's trying to help me with this and I will get it figured out, I'm not going to quit.
 
So for future reference, what items can i safely unplug. the rear light, head lights, hand warms and thumb warmer? and thats it right?
 
I had a little time today so I wanted to check a couple of things. I cleaned up the ground strap by the power valve servo it was slightly corroded. Then I wanted to check my reeds since they are V Force 3's and I've heard their prone to chip. The first thing I noticed was the airbox was wet with gas/oil and when I removed it I could see where it was dripping inside and making a oily mess underneath. It looked like from the airbox that it was coming from all three carbs. When I got the reeds out I noticed something odd. All the petals had the black side facing out except the top ones which have a greenish colored face facing out. They look backwards compared to the other petals. Oh and there weren't any cracks or chips. Would this cause my problems with the rpm and the mess in my airbox ? I can try it tomorrow, but I wondered what someone thought before I put it back together. I also thought maybe the o ring in the needle and seat could be bad, but I thought it'd be weird for all three to be bad and I didn't think they looked bad when I cleaned the carbs. I also have a cdi box I can try if none of this fixes the problem. There doesn't seem to be a real good test for sure if the stator is bad so I'm just trying to eliminate all the other possible options before I shell out the cash for a new stator. I gotten burned just changing parts before.
 
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Well my bad I looked at my reeds closer and they are V Force 1 reeds and apparently the top reeds are a greenish color since when I pulled the reed petals off they are that color all the way through. I pulled the flywheel off and cleaned up the inside of it and the stator itself there was some rust on both. I unhooked the wire for the shield defroster from the PV test port and I'm going to do a compression test and see what happens.
 
Hope you get it figured out, my srx is about the same way right now, 8000 is max. I've got a brand new belt, and some secondary buttons ordered and I'm going to play around with the clutching and jetting some more, and double check my PV's. It was terrible before, would hit 8000 then drop to 7000, I dropped the jetting a bit and it got better. It only goes to 8000-8100 but doesn't drop anymore and seems to have better power.
 
I think I figured out what is wrong finally !! After I got everything back together I did a compression test. First I did it with a cold engine and from the left to right I got 100 100 95 psi. Then I let the engine warm up for a few minutes while I took care of my tools and I checked it again. From left to right I got 95 95 and 85 psi. These numbers seem quite low and the tester I has does have a 12" hose which would lower the readings a little, but I think its accurate enough to know that it needs something is off. I have a Bender/Peak head, what kind of compression should I have with this? Are the head and base gasket reusable or do I need all new and if so what brand would you recommend ? I wish I found this earlier when it was nice and warm out, its supposed to be below zero at night now for most of the week, brrr. I just never would've guessed my compression would be so low because it seemed to start and run so good. I don't think I'm going to run it anymore till I get it fixed because I don't want to take a chance on a broken ring. I've probably been lucky so far. Let me know if you think this is the cause or not, but I guess it would make sense that the engine would run out of steam and not be able to pull the rpm. This was a great learning experience and I did find other things that were wrong and needed to be changed like the clutch components and belt. Thank you everyone for your help again.
 
holy tolito!!!! lol compression is way down. Lucky!!! I am really guessing that has something to do with that head you have. I am still searching for mine. I will post back when i get the clutch components and see if it helps
 
Does anyone know what kind of compression I should be getting with these Bender heads ? I'm going to try to take it apart this weekend in a heated garage and see what's going on in there. Hopefully I only need to re ring it.
 
Similar problem here too.

Looks like I am having a similar problem.

Mine ran great until I started to get a chuncking noise/feel in the drive train. I replaced every bearing in the sled. Put it all back together and go for a rip. Same issue as the OP...wont rev past 7500...occasionally it will rev to 8k off the line, then goes back down to 7500. Put a new belt on and no change. notice the belt is riding really high on the secondary. Squealing at idle as well. Pull the secondary to find that the three bolts to adjust are gone. No where to be found. Get lucky and find 3 metric bolts off my Roadstar Warrior that fit perfect and get the secondary where it needs to be...maybe even a little too loose. Go for another rip....same deal.

Change plugs, loosen track, check pv servo...go for another rip. Same deal. Keep riding it anyway, trying to figure something out. One run I ease into it until I get to 40mph then peg it....it revs!!! Straight to 8500. Do it again the same way and it hits 8500. Go back to nailing it off the line and it goes right to 8500...all is well. Ride around for another 15 minutes and all is good.

So what's going on here??? My guess is the stator...but usually it seems like they get worse the hotter they get....this case seems to be the opposite....
 
Seems like a common problem on here. My 2000 SRX was doing about the same thing, checked everything over and all looked good but it was jetted way too rich so I dropped it down a bit and made a big difference. It still could be better so I will probably jet it to the 01 specs. Seems like the colder it is outside the better it performs.
 
I hope a top end rebuild will take care of the problem, but I wouldn't be surprised if it needs a stator too even though everything electrical seems fine, but it needs the top end done anyways. It would be nice if that' all it needs and then I'll be ready when the snow comes. Its hard to track down a problem like this sometimes when there are multiple things that can causes for the same issue. I bought a sled that had a lot of mods done to it so now I'm going through and fixing everything I find wrong and also getting it set up the way I want it. It'll be worth it though because these sleds are still a lot of fun.
 
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not the compression in my opinion, think about or go back and read this whole post, you got peak rpm then you didnt, then you got it again. If the compression was the problem it wouldnt vary the rpm at differnt times as it would be down on power ALL the time.

I hate to see people waste money on stuff thats not the cause but everyone has there own way of doing things.

while a 100lbs is on the lower end, theres differnt compression guages give differnt readings.

It also could be from the bender head gasket and also if the heads been modded and is matched to the pto cylinder which was larger. The opticool gasket makes the squish larger which reduces compression as does the head mod, BUT, a low compression motor makes rpm easier. Like I said its your $$ but thats not the problem in my opinion, you need to replace the stator first with either a known good unit or brand new yamaha.......
 
since went the viper and srx use the same stator ??I think I will try one too .....
 
2000-02 srx and all vipers use the same stator.

Just stay away from aftermarket ones, your not going to want to do the job twice, this is where it pays dearly to buy either the oem yamaha stator or a known good unit. The aftermarket ones are junk,90% of the time the pick up coil will not even fire the engine,been there done that,and fixed a few more from people who put them in to give up why the sled runs weird or doesnt run at all!
 
don't worried I know aftermarket sucks ...been there with rm stator for 4 wheeler I will never again
 
modsrx said:
don't worried I know aftermarket sucks ...been there with rm stator for 4 wheeler I will never again
Click to expand...

I bought an aftermarket stator for an RM80 once and had good luck with it, would never put one on a sled though, alot more work to change one on a sled than a dirtbike. It's well worth the extra $$ to go with OEM. Aftermarket really isn't much cheaper anyways, $139 compared to $169 for OEM.
 
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shaggyzr2 said:
I bought an aftermarket stator for an RM80 once and had good luck with it, would never put one on a sled though, alot more work to change one on a sled than a dirtbike. It's well worth the extra $$ to go with OEM. Aftermarket really isn't much cheaper anyways, $139 compared to $169 for OEM.
Click to expand...


it was not a rm bike its the place been call rm stator
 
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