Yamaha Grizzly 700 will not start
 

I have a 2008 Yamaha Grizzly 700 EFI Quad and I cannot get it to start, this machine is used almost every day and the day previous it was running fine when I parked it back into the shop. The next day I tried to start it and it just will not run. It has power, cranks, has fuel, & spark, and no ECM Codes are present. I have the manual for the machine and I think I have gone through each and every check and balance to diagnose the problem and cannot find a problem. I have over 40 years of trouble shooting and fixing things and this one has me completely stumped. :angry3:

I am at the point of taking it to a dealer, and I am asking if anyone on here can recommend a Yamaha dealer that is very good at trouble shooting a problem like this. I have tried all the ATV Forums looking for a similar situation and have even posted on one for some tips and help, but no joy there.
I would be willing to take it to any dealer between Nanton and Airdrie, so hopefully someone can make a recommendation. Thanks

http://www.outdoorsmenforum.ca/showthread.php?t=369634

maybe this old thread will help

Mine needed a new battery. Would turnover fine. (Seemed to anyways). Boost it with a good battery’s. You will know right away

I know of a 2007 Grizzly that was run low on fuel, and the fuel pump was damaged. so it only put out a very small amount of fuel, not enough to run. I would guess not enough fuel or a weak spark

If the battery has power but the engine isn't turning over, maybe the battery doesn't have enough cold crank amps to turn it over in this weather. In that case a new battery would fix this

Try putting a new plug in it. Just because you have spark doesn’t mean it’s a good spark.

Fuel or carb ice ?? Sorry, no carb, but maybe still ice.

Ice somewhere in fuel system??

not sure on your quad, but on my honda 420 there is a kill switch on the handle bars.

i never use it, but i guess one time when i was getting off the quad i bumped it.
didnt realize this when i went to start it the next time. took me an hour to figure out why it wouldnt start.

felt kinda dumb once i figured it out.

on my quad it also has a switch to turn the fuel to "reserve" did someone play a trick on your and switch it on yours? once the reserve fuel is used up, the quad wont run.

Your shop is heated? My Grizzly did not like to start in very cold weather until I switched to synthetic oil.

I would change the plug and bypass the on/off switch with a paperclip and see what it does...

I have the same year and model and maintain it impeccably.
This year suddenly it would crank but not start.
Went through all the things you mentioned.
I called a shop and spoke to the senior mechanic who told me to change the spark plug.
I told him the plug was fine.
He told me to change the plug anyway.
I told him I took it out, was clean as could be, good gap and when grounded it sparked just fine.
He told me to change the plug anyway.
I ignored him and chased down every other thing like the fuel pump, switch, etc. Nothing worked.
Then I changed the damn plug and it started right up.
Apparently ( and I did not know this) a plug can/will behave differently under compression and this is not uncommon even though it appears fine.
Give it a try, worse case you have a spare plug for when you need it...

Spark plug or computer problem.

If it has fuel, compression and spark, assuming it is still timed correctly. It has to run. Spark plugs do fail under compression. That’s the easiest route, change it and see what happens- or you’ve missed or are assuming something is present but not actually.
Good luck. It shouldn’t be difficult.
Tullfan

Spark plug. Under compression, the arc jump is equivilant to 6-8 times the length at atmospheric pressure. At least you know your coil is likely good. A spark plug is like $10 at worst case?? Give it a shot. Get NGK or Bosch.

If replacing the battery, get a Yuasa battery. Every other battery I tried was junk in the Griz. Sask Battery had the Yuasa battery for $10 more shipped than other places were selling cheap batteries for. Some of the cheap batteries were only lasting a few months.

If your battery is the problem, it's not worth frying the display over a cheap battery.

Yup!!! Even though your spark may look good on spark plug and plug looks ok. When you screw it back into head that spark changes Switch spark plugs, that is the very first thing I do with a no start if it’s got air, fuel, compression, and spark. It’s probably the cheapest thing you can try besides what some guys feel is a “mechanic”in a can sea foam.

If that doesn’t work. If you have fuel hows the pressure? And if pressures ok how’s the flow?

If it's a 2 stroke, first thing I try is new plugs!!! Fixed the reverse on a sled I bought!

Did you look into the stator? I had to replace the stator in one of my grizz 700’s.

X2

9 times out of 10 the plug fixes the problem!

Yup new plug, whenever mine won’t start that’s usually what does it.

LC

Does the fuel pump kick in to prime itself when you turn the key? If not pull the fuse cover and pull off the fuel pump relay & dry it out. Reinstall with dielectric grease and fire it up.
Had this happen to me on an old grizz during a cold snap

Well all good tips from you fellas. Thanks

The machine is in a heated shop, and this happened, (Dec. last year) before the cold snap. Just to give you some background the quad was running perfect when I put it back into my shop, we use it around here just moving snow, harrowing, pulling a small manure spreader, so no hard trail riding.
I came out the next day and turned the key and I heard two loud snaps like electric sparks. This was before I pushed the start button, then it wouldn't start, it cranked OK and did the backfire thing but no go. I initially went to checking all the fuses and relays under the hood, but all good.

And yes the first thing I did was spark plug x2 new ones, tried them both. Kill switch is good, or it wouldn't crank.

After going though the shop manual for diagnosing and checking all the ECM components I initially thought it was a sheared woodruff key on the crank but having taken that apart it was in perfect shape. When I had the cover off it was apparent that the stator looked a little burnt, and the reading from the crankshaft position sensor was slightly lower than the factory specs call for. So since Christmas I ordered a new stator w/sensor and put that in.

It's all back together with a new stator, new CPS, new plug, all tests available from the ECM options work, like spark plug firing, injector injecting, fuel pump relay cycling all OK. The battery was new in October, and I have it on a maintainer currently so it's fully charged each time I try to crank it.
When I crank it over it may initially backfire though the exhaust and then if I keep cranking it and working the throttle it will backfire out the throttle body with flame, so plenty of gas and spark available to do that.
That would mean one of two things, valves are opening at the wrong time, or the ignition timing is wrong. I have addressed the valve lash and set it to spec as per manual, did it twice actually just to be sure I had the timing marks correctly aligned to TDC as per the manuals procedure. The only thing that I have read about is if the timing chain has stretched or slipped (ha). Having a good look at it it is tight on the sprockets there is no slop and no way it could have slipped, (it wasn't running at the time it died).

To further eliminate potential components, I happen to have a second identical Grizzly 700, so I pulled the ECM from the dead machine put it into the good machine and it started. I also pulled the Spark Coil from the bad machine and it too started the good machine. Neither good component started the bad machine. But I had to try.
I drained the fuel and put in some new fuel with a splash of Seafoam for good measure, but all to no avail. I did not do a compression test, as I don't have the correct fitting for that sparkplug thread, but I think it would start even with low compression, but like I mentioned it was working up until I shut it off normally for the day.

I still have that SNAP - SNAP in my mind from when I turned the key that morning. I have tested the 3 diodes in the wiring harness, I have cleaned ground points and re-torqued the connections.

I mean everything works it just will not start. That's why maybe a dealer or a fresh pair of eyes are needed to find what I may have missed. I see that there are many terminating caps on the wiring harness that may be connection points for the dealer to hook up some better diagnostic tool??

Help :(:(

Soooo, if it is back firing out the exhaust, or intake makes me think timing. Have you actually confirmed that the rotor is on top dead center mark, the cam marks lined up as they should aaaannnd, the piston is actually at the top of its stroke.
It does not make any sense that it won’t start. If it still wont start back to basics. Fuel, air, spark.
No starts to be honest shouldnt take any more than an hour. Barring any hard parts that are broken. It really is simple.
If you can’t get it going pm me your address and I’ll come out. I’m always up for a challenge, especially a fun one. Barring any broken parts, I should be able to get it running or point you in the broken component direction.
Tullfan

Appreciate the offer
 

Yes I did go through the process twice, pulled the plug and used a probe to determine TDC of the piston at the same position as the two timing marks.

The indicator line on the camshaft end has me a little puzzled, as it is slightly off from the casting mark (arrow). See image.

Attachment 160602

Not sure how perfectly aligned it needs to be, but I can't find anyway to make a small mechanical adjustment to the timing, (like turning the distributor). It does seem to be a bit which could relate to a degree or two, and I think that could be a problem. Other than that it's all electronically timed by the ECM as far as I know.

I can't believe that there is anything "Broken" as like I had mentioned it was running fine when I turned it off normally the day before.

I am going out for Elk tomorrow so depending on how that goes I won't get to do anything with it until maybe Saturday or later.

Thanks for the offer and I will get back to you if you are still willing to have a look.

Thanks to All.

Check your ignition switch and the kill switch. Spray a little contact cleaner in them. I was having a hard time starting my Cat 500 and this helped a lot. Easier starting now. Cheap easy fix if that is the problem.

Well this solution hasn't been posted yet, I'll post...…….Buy a Polaris.....:):)JK


I posted about having problems with my older Yamaha, same issues you've identified and I've pretty much run the course on trying to fix it and gave up and parked it...…..and bought a Polaris. lol Havent had any problems since.

And like you I've spent so much time on it, its got me curious and will get back at trying to fix it sometime this summer.

Buying a new machine usually works no matter what you buy , but long term I would rather have a Yamaha than a Polaris reliability wise.

Buy a Honda and done!

My kodiak 700 did this almost a year after I bought it. See how much pressure your fuel pump is putting out. Mine crapped the bed and they fixed it on warranty, I can’t remember the numbers, needs like 50 psi to run and mine was only putting out 10. Cranking and cci ranking it finally fires but won’t stay running.