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Kenny O.
Kenny O., Motorcycle, ATV, Mules, Side by Side's Product Specialist. All Brands
Category: Motorcycle
Satisfied Customers: 953
Experience:  Worked for Kawasaki Motors as a Product Support Specialist (Factory Support) for 24 years
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Problem with a 4 wheeler, 92 Yamaha warrior 350. Wont start.

Customer Question

problem with a 4 wheeler
JA: Tell me a bit more about what's going on so he can help you best.
Customer: 92 Yamaha warrior 350. Wont start. It had a new crank put in it and new valve seals. Timing is on compression is 120 and i have spark and fuel. All it does is turn over and over and will make a major backfire out the exhaust. But no start
JA: Cars do make very odd noises -- They help the mechanics figure out what's wrong. They are terrific with my old Grand Cherokee. Are you hoping to fix this yourself?
Customer: yes
JA: Great! What have you tried so far?
Customer: Set the timing, adjusted the valves cleaned the carb changed the spark plug
JA: Is there anything else the Mechanic should be aware of about your car?
Customer: when the mark on the flywheel is on the T the piston is not quite TDC
JA: Our top Mechanic is ready to take your case. Just pay the $5 fully refundable deposit and I'll fill the Mechanic in on everything we've discussed. You can go back and forth with the Mechanic until you're 100% satisfied. We guarantee it.
Submitted: 10 months ago.
Category: Motorcycle
Expert:  Pete replied 10 months ago.

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.My info is somewhat limited on your model here but I had seen no one else has responded and would like to see if I can help here.If at any time you feel that I cannot help with this please let me know.

Make sure all wiring was reinstalled onto the engine properly.I have seen some issues where wiring can be installed incorrectly and cause a fault like this here.I would also double check that the engine timing is correct as incorrect timing will cause exactly what is described here.If these are all checked and found o.k. including the timing being double checked to verify it is correct let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 10 months ago.
I have checked and re-checked the timing. I have checked the resistance on the stator wires and they are with in specs. I have a nice blue spark and good compression od 120psi. I checked valves for leakage and there is minimal leakage as per the norm. It is wierd that when the T mark on the flywheel is lined up with notch on motor case and the cam gear mark is lined up with v notch on motor case that the piston is not fully at its top stroke. Piston is up top, but there is stll about 5 degrees of rotation of flywheel to put piston at totaol TDC(just before it is to start down stroke}. Then of course the T is no longer lined up in this position and neither is the cam mark to case mark. Not sure if this is normal that the piston wouldnt be totally even with head at TDC? i pulled head to be sure valves are fully closed and they are. I pulled cam and checked the lobes,they are fine. Rockers are good too. i reassembled cam with pin facing up(lobes down). and re checked the valve clearance. Ex is at .007 and intake is at ,005. Set them at the looser endof specs, but not too lose. Bike still just turns over and over then will randomly make a loud and i me loud detination{backfire}out of exhaust.
Expert:  Pete replied 10 months ago.

Unfortunately this is all of the info I have on this here myself.

I will open your question up for others here to see if someone else can assist further on this as there may be others here that may have more info on what to check or do with this issue.I hope you can get this resolved with ease.No need to reply to my last post here unless it is a last resort as it will keep your question locked to me and others will not be able to view it.If you feel you want to continue to work with me on this feel free to reply at any time but keep in mind in some cases it can be difficult to fully diagnose or help repair this without seeing your vehicle.

Thanks Pete

Expert:  Kenny O. replied 10 months ago.

HI this is Kenny, you still need help on this ?

Customer: replied 10 months ago.
i do
Expert:  Kenny O. replied 10 months ago.

OK good, before I we get started I just need a little background on this failure, you stated that you replaced the crankshaft and valves, can you tell what was the reasoning those were replaced, basically need what was the cause ?

So I will list below some questions that I need answered so I can get my head around what might be going on.

  • Failure, what in your opinion caused this failure ?
  • Was the repair performed by you or someone else ?
  • Parts replaced (All hard parts) not including gaskets & seals ?
  • You stated that you checked the "stator" and said "I have checked the resistance on the stator wires and they are with in specs." If you have those specs please supply them ?
  • Do you have a timing light ?
  • And hours or miles on this unit when the failure occurred

Thanks

Kenny

Customer: replied 10 months ago.
crankshaft( and bearings) was replaced because the old one had a screwed up keyway notch from previous owner. It was cracked and would not hold the flywheel in place. Flywheel notch is fine. The stator wires red to green was 260 ohms and the pick up yellow to blue wires was 196 ohms. was within the specs in the repair manual i have. I did not replace the valves just the valve seals because they came with the gasket kit, so i figured why not. Machine did run with old crank for a little bit until the key would no longer keep flywheel n place and timing changed. I also put a new timing chin in this machine when i put the new crank in. I have re-built 3 of these motors before and changed out cranks and never had a problem until this one.
Expert:  Kenny O. replied 10 months ago.

OK, right now here is where I want to go, you definitely have a timing issues based on everything you say and how the unit is acting, I believe that your flywheel has moved, I will bet right now that you shured a flywheel key. What happens is when the crankshaft gets so disfigured as in this case and needs to be replaced, what also happens in the Morse tappers especially when one of the two parts is not replaced.

So the easiest way to check this is, piston at TDC, by the means of using a dial indicator or a probe while manually turn it over by the flywheel, (DO NOT USE THE "T" MARK ON THE FLYWHEEL) when you think that its on TDC then look at the flywheel mark, also if you remove the flywheel bolt and if the key did shure you might be able to see it, but the keyway slot on the crankshaft should be broached straight up point at the piston.

Let me know what you find, also I can assist you in fixing you old flywheel if the broach on that is not damaged, remember the keyway isn't there to hold the flywheel on the crankshaft, its there only to set the proper timing for flywheel to crankshaft relation.

Thanks

Customer: replied 10 months ago.
Actually when the piston is at true TDC{flush with the top of cylinder ) , the T on the flywheel has already past the notch in the engine case. and of coarse the cam timing mark is past the V in the head housing. If I put piston at true TDC and ignore the T mark and moved the timing chain/ gear back to V mark it probably still wont work right because the pick up coil reads off the flywheel raised section right? If i put a new flywheel on will it fix the timing issue?
Expert:  Kenny O. replied 10 months ago.

Lets pull the flywheel, when you pull the center bolt out, you should be able to see if the key shured, based on what you are saying the flywheel is not where its suppose to be.

Lets verify that first

Customer: replied 10 months ago.
Ok I will be able to do that tomorrow afternoon.
Expert:  Kenny O. replied 10 months ago.

No problem, just get back and then we can check to see if you can use that old flywheel, if you can tomorrow go by an auto parts store and grab a tube of medium and fine valve lapping compound, I'll direct you to how to lap in a flywheel and that will also give use an idea if the taper is bad.

Customer: replied 10 months ago.
ok. i will and i will get back to u tomorrow, thanks
Expert:  Kenny O. replied 10 months ago.

Morning, come up with anything ?

Customer: replied 10 months ago.
good news thanks so much.I took old flywheel off and it was definitely F up.It looked like the outer ring had shifted. The key was still on the crank and the crank keyway was fine. I got another flywheel from a parts machine and lapped in that one to the crank. The T was right on the mark. Put it back together and the machine started right up. Adjusted the carb and she is running fine.I had another question about a 97 Kawasaki klx300f. Need to change shims to get the right valve clearance on one ex valve and one intake. Both are way too tight. Cannot even get the lowest of the specs feeler gauge to fit . I changed the rings and have no compression, so I am assuming that the valves that are too tight are not closing to create compression. Am i on the right track here? Thanks
Expert:  Kenny O. replied 10 months ago.

Good, I figured that was the problem, your KLX300-A2 is shim under bucket, clearance is below, also when the clearance goes away like that usually the hard facing on the valve has gone away, so likely you are going to need valves sooner or later, you might adjust them out here and if it comes back hard starting then you will likely need to put valve in it.

  • Exhaust .15~.24mm (.006~.009in)
  • Intake .10~.19mm (.004~.007in)

Thanks, ***** ***** got it going !

Customer: replied 10 months ago.
i can put smaller shims in the 3 that are past low tolerance to get em back in specs?
Expert:  Kenny O. replied 10 months ago.

every shim is .002 inches, (I don't use metric) So say you have a valve on the exhaust that has .002in of clearance, the shim is a 280, to get it in the middle of the spec you put a 275 in it, that would allow you .006 more clearance bringing the total clearance to .008in, on Kawasaki's its best to set the clearance to the looser end f the spec, they run a truer cam timing.