Sha35297

Yeah, I asked around here locally and no one had the same bike for me to do the swap with. That would have been ideal. On the more common models that I work on, I have a spare ECU that I can do a quick test and see if that is the issue. This bike wasn't something I see around here very often. I picked up a tote full of ECU's and other misc. electronics from a shop that was closing down. Got that and several other useful items for a good price.

Just wanted to give a final update on this bike. Nothing I tried solved the issue. Leads me to believe that the only other problem could be the ECU module or the EPS module. The customer did not want to spend the $800+/- to test the theory. I really hate unsolved mystery, but I gave it my all. Sorry I couldn't come back with a positive update.

I’m not sure where to look to find the starter feed you are talking about. I’m not seeing it in the manual. It’s a 2010 Grizzly 700 FI EPS 4WD. I have a 2004 Grizzly 660 in my shop as well. I tested the pick up coil on it. There is no continuity between the frame and either wire on this one. Which leads me to believe that is most likely my problem. It just isn’t faulted bad enough to prevent the bike from running once it’s started. Also, makes sense that it gets worse once it’s warmed up. It will fail completely soon if not replaced. Thank you for all of your input. It’s nice to be able to bounce ideas to other people and get feedback. I enjoy a good challenge. It is very satisfying once it’s solved. I will update with any new info.

Ok, So wiring it testing good to TPS and Speed Sensor. I did some more testing on sensors and found that the speed sensor is out of spec. Which is most likely the issue with EPS. However, I still do not see anything anywhere that says this would cause the hard start issue. I even unplugged the sensor completely and started it. I acts the same way. So I moved on to the pick up coil. The manual says it should have 459-561 OHMs. I'm getting 601 OHMs. Also, should there be continuity between either of the pick up coil wires and ground? I'm getting 10-12K OHMs there. The manual does not specify this test, but I believe there should not be any contact to ground on that coil. This may be the whole issue.

Ok, Update on this problem. I have cleaned the IAC, it was perfectly clean to begin with. Started the bike with it out and watched it function. Seems to be working as designed. I replaced the TPS, I did a test on the OHM reading while rotating it from open to closed. I used a meter with a graph. The signal would spike up and back down at one point in both directions. Everything else tested good. With the new TPS I have been able to get the idle to calm down a little. However, it sill has the hard start periodically. It is a strange issue, the majority of the time, it will start just fine. When it does decide to act up, it will pop and just sound horrible, but once it starts, it runs great. As far as the EPS codes, yes they are only for that module. It stores its own codes separate from the ECM. I've read that the speed sensor will cause these issues as well, but it passes every test in the book perfectly. I'm going to do OHM tests on every wire in that part of the system and see of anything seems out of wack. Seems like it has to be a wiring issue maybe. The issue is so random though. It will do it on cold starts sometimes, but mostly after warmed up. The throttle cable is adjusted with about 1/8" of free play as well. Diag reading on the TPS is between 15-20. For some reason I still keep wanting to say valve adjustment, but I have already checked them twice. Unless my manual is giving me the wrong specs.... Battery is brand new, starter does not dragging or straining at all. When it has the issue, it sounds just like the timing would be off or valves would be out of adjustment. Sometimes backfiring in the exhaust. I will update with any findings in the wiring system. If nothing is found there, I will have to think that it is the EPS issue causing everything. Which is not a good problem. The module is about $800. I wish I had a spare to plug in and try. I don't know anyone with the same bike anywhere near me.

Mech, Thank you for your responses. So lets start from the codes. The EPS system on this bike has its own coding system separate from the engine coding system that displays on the screen. I followed the procedure to pull codes from the EPS module because the EPS light is staying on. That's where those codes come from. According to the manual, those codes mean say low power to EPS module and welded contacts in the EPS module relay. I have checked the power going into the module which is same as battery (Brand new AGM battery). I also have tested all relays in the system. I also removed the IAC module and cleaned it good. It wasn't really too bad. However, I did do a few test starts with it completely removed and it started every time that way. Just idled up very high. So this could still be the culprit. This bike has the Auto Compression Release. Could this be why it states to only have 71.7psi Max? The bike runs great when its running. No smoke or lack of power at all. Oh, and when I go into diag mode on the display, there are no codes. Other than codes from when I ran it with a sensor or module unplugged. Then it would throw a code, but will clear itself once plugged back in. I have the idle adjustment screw backed out as much as possible and the cable adjustment so that there is slack in the throttle. It should idle down lower than it is. So this does lead me to believe that the IAC is a problem. I just hate replacing parts for no reason. Which is why I came here for further advice, before becoming a parts changer.

I completely forgot to give an update on this issue. It was the timing. It had jumped a tooth. I must have missed it when I had checked it the time before. I replaced the chain and tensioner. The bike has been in use for over a year now. The guy uses it daily for work. Thanks everyone for the help.

So I have used the service manual to troubleshoot every sensor on this bike. Everything tests good accept the EPS Control unit. However, I do not see anything in the manual that suggests that this will cause the issue that I am having. The bike will start instantly when the button is pressed sometimes and then other times it wants to turn over forever and make a horrible knocking sound. Sometimes backfiring. After cycling the ignition it will sometimes start up right away. I have triple checked the timing and also the valve clearances. Everything checks out. The bike is for a customer that really doesn't know anything about the bike. From what I can see, the cylinder appears to be new, along with the starter. I did a compression test and it is a little high (74psi) Book says 71.7 is max. I can't see this little bit causing the problem, but I could be wrong. Last thing is that the idle is a little high. I have tried everything to get it to slow down with no avail. When I put it in gear it will jump slightly and is hard to get back into neutral due to high RPM's. Any Ideas or suggestions will be greatly appreciated.

So the fuel pump I replaced was aftermarket. I only replaced the pump itself and used original can. It came with new filter and seals. I'm not sure how the pressure regulator works on this system. It is only a spring valve. So what exactly tells the ECM when to cut the fuel pump on and off? Timing is set and valves are adjusted correctly. I guess the next step is to just replace the whole fuel pump canister. I will place the order for the new one and update once its installed. I am pretty certain that its a fuel pressure issue. Just not sure if its an electrical issue causing the pump to cut off when its throttled up or something else.

So I rebuilt this engine completely with all factory parts. Transmission was damaged, so customer wanted to replace crank while I had it apart. After putting everything back together, everything worked great. Customer picked up bike and ran it for about two months (he uses it daily for work in crawfish ponds). Brought it back to me because it was overheating and would rev up to about half throttle and the cut out over and over while holding the throttle at anything above half throttle. Radiator was plugged. Everything with ignition tests good. I never loose fire while this is happening. ECM is brand new, fuel pump is new, injector is new, swapped TP Sensor with known good one. Fuel pressure is at 51psi at idle and its hard to tell because of vibration, but seems to drop to about 42psi while its cutting in and out at high rev. Any ideas on what could cause this?

Just a final update. Customer had the old cylinder bored oversized and used a Namura piston. Got it all put together a couple days ago. All is good now. Customer is happy. Thanks for the help everyone.

Thanks for your response. Yes I have moved the slide needle to every position. It has some effect, but nothing that fixes the problem. I’ve tried larger and smaller jets with no change in idle performance. I believe I’m going to replace the intake manifold and see from there.

Hello, I have an 86' 200SX. Customer brought it in with rusty dry gas tank and said it ran good, but would not idle. I cleaned the carb, completely cleaned and coated the inside of the tank with fuel tank kit. Came out great. Fresh fuel and Cleaned carb, adjusted valves. The bike will run great all day long as long as you don't let it idle. It will idle very high, then slow to a low idle for a few seconds and then backfire and die. I replaced carb with a brand new one, still does the same thing. Sealed off the air box with no improvement. Sprayed the intake manifold with carb cleaner while running and it did rev up the rpms. So I removed it and coated it good with some Flex Seal (just to test if it would help) After reinstalling the it, It still does the same thing. Any Ideas of what else could cause this problem if it is not the Intake manifold? I'm running out of options. I also replaced the O-Ring on the Intake.

I have now gone through 4 starter idler gears on this bike. I've checked and rechecked timing marks. Nothing seems to explain what is happening. I read somewhere that the temp sensor is bad and causing the timing of the spark to be off and backfire. However, I have not been able to locate any kind of temp sensor on this particular bike, and I see no way to adjust the timing of the spark. Anyone come across this before? I cant keep going through these gears for $30 each.

Well this was a kit brought to me by the customer made by Niche. I did not measure before installing. Guess in the future I will though. First time I’ve had an issue like this. The customer decided to take the original cylinder and send to a machine shop to be bored. Guess I’ll see how it turns out when I get it back.

Hello, So I decided to remove the new cylinder and piston to swap back out with one I had from another bike. I noticed excess wear on the skirt of the piston and inside of the cylinder. Both were purchased from Niche as a kit. They have less than an hour of running time on them. Swapped with the jug and piston from the other bike and the noise is gone. My customer is going to attempt to return the kit he purchased from Niche and purchase a new OEM from factory. Hopefully the next one works right. Thank you everyone for the help. It is greatly appreciated. Hopefully this thread can help someone else in the future.

Thank you for the input. It does have a copper gasket in it that I had replaced the first time I tore it down. I could try replacing it again to be sure its not the issue. While its running I cannot see or feel any combustion coming from around that area though. I've had exhaust leaks before that did not sound like this. That's why it has me stumped so bad. I feel like I have tried all of the obvious things multiple times and have become sort of blind to being able to see past what I know I have already done. Was hoping a fresh set of eyes or thoughts on it would trigger something new. I am attempting to upload the video again a different way. The one I have already uploaded plays on my computer, but will not play from my mobile device on the website. video-1611872782.mp4

This is the header. I'm not seeing anything abnormal about it.

Just removed the rear crank case cover again. These are the pics of inside. I used a screwdriver to verify piston was at TDC. All marks are lined up.

Ok, With the Stethoscope it seems like the noise is loudest in the valve cover. What is strange to me is that I have replaced the whole top end with another one from a bike that I know runs good with no issues. So what would cause the same noise to be in the valves on both cylinder heads? Also, after listening better to the timing of the sound. It is in sync with the exhaust not the piston. I'm going to pull the crank case cover again and check the timing one more time and post pics of the inside to post.

Hello Mech, Thank your for responding. So, I did test ride before doing the repair and this particular sound was not there. The original noise was a rubbing sound on the rear crank case. After replacing timing chain that noise went away and this new sound appeared. Noise is not apparent at idle on cold start or when warmed up. It starts at about 1/4 throttle and speeds up and slows down with the rev of the engine. Seems to be at the speed of the piston, not speed of the valves. Piston Pin fit is good. I've tried using a screwdriver to pinpoint the location. Seems to be more prevalent on the exhaust side, but hard to tell if its crank case or top end. I bought a stethoscope to try to pinpoint the sound better. I'll update on that when I get back in the shop.

Hello, got this bike in to replace the jug and piston. Made the swap, crank looks good, no play in connecting rod. Put it all back together and then heard a rubbing noise in the rear crank case. Ordered a new timing chain and tensioner. Installed them and put it all back together. Fired it up and ran great on the work bench. Took it down and went for a ride and noticed the higher the rpms, the noisier it got. There was a tapping noise on the exhaust side of the valve cover. Removed valve cover. Checked valve clearances, all good. Checked the valve springs, the were a good bit out of tolerance. Installed brand new springs. Same noise. Decided to replace the whole cylinder head with one from a known good bike. Still the same noise. Decided to replace the camshaft with one from a known good bike. Still makes the noise. Replaced lift caps. No change. I’m at a loss on what could be causing this noise. It’s very loud and not normal by any means. Any suggestions would be appreciated. Video doesn’t really pick up the noise good, but it’s there. Thanks IMG_2225.MOV

So, I got this 07' Polaris Outlaw 90 in the shop to rebuild top end and transmission. Replaced all bearings and gears in the transmission. Replaced cylinder and piston with brand new parts. Put the engine back on the frame and fired it up. Started great, but had a taping sound in the lower crank case. pulled the flywheel cover off and found the flywheel was wobbling and hitting the stator. I then replaced the stator and flywheel with brand new parts. Timing is all set on the timing marks now, but when I turn it over it kicks back when it fires and ends up stripping the starter idler gear. I've replaced the starter gear once already and now have to replace it again. Is it possible that the timing marks on the flywheel are off or maybe this flywheel is not for this exact model? Thinking of advancing the timing to try it, but don't want to keep going through idler gears.

Hello, Just wanted to give an update. I found a couple broken teeth on one of the gears. Ordered a new one, had the correct part number, but was the wrong part. Found a used one on Ebay. Got it in over the weekend and installed it this morning. No more knocking sound. Simple fix I guess. Thanks for the help.

Mech, Thank you for the quick response. I will give it a good look over in the morning and update what I find. I didn’t even consider whims before this. Hopefully I can see some obvious wear and go from there.