This is a discussion on Timing chain Issues within the Grizzly Engine & Transmission forums, part of the Grizzly Forums category; I was washing my grizzly today to find this bolt very loose with oil around it. At the time I wasn't quite sure what it ...
I was washing my grizzly today to find this bolt very loose with oil around it. At the time I wasn't quite sure what it was, after calling someone I found out it was the timing chain tensioner. In another thread I had commented about how my bike is continually getting harder and harder to start, and it also making a loud clacking noise. When I started it today it I held on the starter button for about 6 seconds(it just turning over)before it tried to fire-off..the entire time making this loud noise. As soon as it turned over it blew a strong puff of dust out of my intake(snorkles)..is that normal?
If this was loose I would assume the tensioner wasn't holding the chain tight enough, right?
I'm afraid that if the tension isn't right then the timing is off and the loud noise may be the piston hitting the valves. It is a very solid, and very loud metal to metal sound.
Is any of this accurate or could anyone please give me some advice on this? I'm kinda freaked out by all of this.
Well if the tensioner is tight and hasnt adjusted, the sound your hearing could be the timing chain slapping around. Is the bolt tight? I dont know what kind of timing chain adjuster the bike has, but i know on some bikes that arent auto tensioning you need to loosen the bolt, the tensioner tightens up, and tighten the bolt back up.
__________________ 08' Grizzly 700 EPS: US Yamaha front brushguard, Full ricochet skids, 3.5" Rox risers, solex bars, odi grips, rox handguards, 27" Maxxis zillas, Tamarack Classic box, Viper 3k winch, 2r tip, 2r foot pegs and traction rails, 2r front receiver, uni filter, pod mod, hanger mod, greasless, Rigid D2s, Rigid 10" SR
I tightened the bolt now, but it still makes the same noise. I don't know whats going on inside there. I don't know as much about these motors as I should and thats becoming readily apparent. I looked on Yamaha on the exploded parts view. I don't think it was the chain itself slapping around because of the guides on either side of it. I could very well be wrong.
Last edited by EzekielRoyale; 06-12-2009 at 09:50 PM..
Inside that bolt is a long spring. This bike does have auto tension adjustment.
The spring pushes on the chain guide, which has a "click type" tension - to prevent the chain tensioner from loosing. So this bolt and spring can be completely removed and not effect the current tension setting.
You will need to keep looking to figure out the problem. Start with the upper left cover plate with the vent tube. Take that off and look at the chain for timing and tension.
It is difficult to repair and figure out problems via computer.
Well, I didn't start at the top end..I started with the crankcase cover opposite the clutch, I pulled it off to find something that looked like something out of the jetsons or something lol.
The cam chain is tight now, but I believe it needs to be re-timed..any advice on this one???
I thought the hose at the bottom corner was coming off the thermostat, surprise, it was the water pump and it's got an alarming amount of slack in it. It's loose enough that i can, with little effort, remove it from the bottom pulley simply due to the lack of tension.
It's been hitting the side of the case, cutting two grooves (a hair under 1/16th deep) in the crankcase. Also the guide/guard on the right hand side is nearly cut apart from the chain slapping it. Further more behind the main sprocket on the crank is a bolt head that is missing roughtly a 1/4 of the head, from the chain slapping against it. The outside surface of the chain is for the most part smooth, it's missing all the little bumps that a chain typically has. It's a miracle I haven't had it jump off yet!
With the cover off...
Picture of the chain, notice the guide towards the top of the picture as well as the scarring on the case. It doesn't look that bad in the picture, but it's pretty rough in person.
I'm thinking I need to order a new waterpump chain, guide/guard thing, a new gasket, and maybe a service manual lol.
I put a wrench on the crank and tried to turn it over slowly, when I do I hear a loud hissing coming from the inside of the motor at the bottom of the cylinder. Could that be air getting past the piston?? I'm wondering if that could be part of my oil burning problem, as well as my compression leak.
I can't find this stupid water pump chain anywhere online to order it, since the shops are all closed now.
Any help/advice would be greatly appreciated guys!!
Mine is very similar except the chain came off completely on its own. The case is eaten into like the pic above and there are two bolts and a bracket that are eaten away by the chain as well. The guide is completely chewed away nearly all of it is gone, less than what the pics show about.
So, either the chain is stretched out or the sprokets are worn, or the guide (which is way too small) wore too much. No reason to roll the dice on which one crapped out causing it to happen.
So I am replacing both sprokets, the chain, the guide, and both bolts. Including the gasket for the case this comes in just over $100 from Yamaha with me doing the work.
Unfortunately the bike is out of warranty timewise but with right at 500 miles on it I am very suprised this has happened. The only without the water pump running but also of course the oil pump wasn't running and there was no way for me to know that. So hopefully there isn't much if any engine damage, it was only ridden back to camp because it was getting so hot so fast and then run a few more times at idle trying to diagnose the cooling problem.
On another note I cannot have this overheating crap and am going to get a new radiator built for this thing. I have plenty of experience with weak cooling systems and this will be the second go around with such a problem. After I get it redesigned I will make it available here so that nobody has to have a hot running 700 Grizz ever again. If I can cure the LLY Duramax from overheating towing huge loads in the mountains on over 100* days then I can knock out Grizzly overheating too.
Did this fix your engine noise? I have a similar problem, engine runs nice and smooth and quiet then develops a LOUD rattle like bad valves. The bike only has 500 Kms. I have checked cluthes valves and almost every other engine part. I am now close to tearing the top end apart to see if it has a scuffed piston. What you are describing seems a lot easier to check. Let me know how you made out.
Did this fix your engine noise? I have a similar problem, engine runs nice and smooth and quiet then develops a LOUD rattle like bad valves. The bike only has 500 Kms. I have checked cluthes valves and almost every other engine part. I am now close to tearing the top end apart to see if it has a scuffed piston. What you are describing seems a lot easier to check. Let me know how you made out.
Thanks
Yes the timing chain and oil pump chain needed replacement. Bike is quiet and runs perfect now. It really sounded like valve clatter but was not. If the sound is more prevalent on the exhaust pipe side of the bike, possibly even coming from the exhaust pipe shielding, then I bet its the chain or chains clattering.
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