Always rotate your Clutch CCW to prevent issues when changing clutch parts!!

[603NytroXTX]

Well I think I just did this. I was taking clutch weights out to adjust and just wasn't thinking about it. I went to start it back up and it runs like #*$&@ now. Where do I start? Pull plugs and rotate? What's the quickest way to check timing? @grizztracks

 

[Turboflash]

Probably have to pull valve cover off.
Could do it with depth micrometer checking cylinder 3 to TDC and comparing to stator markings. But easiest way is to remove valve cover.

 

[603NytroXTX]

Thanks @Turboflash. I'm working on pulling the valve cover now. I'm very well versed on everything Nytro except for the internals. What am I looking for once the cover is off?

 

[Turboflash]

Should be 4 short lines (2 on each cam) that line up with each other lined up with head when cylinder 3 is at top dead center (check stator marks through small stator cover housing hole.
..

 

[603NytroXTX]

Great thank you so much @Turboflash . Just as an update I have plugs out and the primary spins freely and does not feel like it's contacting anything. Working on getting the valve cover off now.

 

[Turboflash]

Great thank you so much @Turboflash . Just as an update I have plugs out and the primary spins freely and does not feel like it's contacting anything. Working on getting the valve cover off now.

If it's only off one tooth pistons won't contact valves. It might start but it will run like sh@&t. Two or more teeth pistons will hit valves.

 

[YukonMP]

Great thank you so much @Turboflash . Just as an update I have plugs out and the primary spins freely and does not feel like it's contacting anything. Working on getting the valve cover off now.

Sounds like it might work out for you good luck.

I'm crashing your thread to suggest guys pull out a heavy black marker and put a CCW arrow on the clutch face. I'm old enough to need reminders like this.

 

[603NytroXTX]

That's a great idea @YukonMP!

Okay so here's where I'm at. We're at TDC and the intake gear is off as shown in the picture. Now how do I go about adjust this?

Edit: I'm noticing as you can see in the picture that the chain does not look like it's seated on the exhaust gear.

 

[DMCTurbo]

Should look like this. See how the 4 lines are lined up with the head.

 

[1nc 2000]

Cam chain is not engaged in the gear on the intake cam.

 

[Turboflash]

Is chain loose?
IMO you should get a service manual that details how to align cams. It's not that hard but it needs to be done exactly right.
In my experience, you have to remove cam chain tensioner to do it. That involves ALLOT. Need to tilt whole engine forward to gain access to tensioner as it's located behind jackshaft near chain case end. It's a pitiful design from a servicing standpoint but we should remember this 998 engine first came out in non-turbo version in YXZ-1000R Yamaha SxS. In that machine, you can get right at tensioner. Once this 998 got put in snowmobile, it's a disaster to get at tensioner.

 

[TrueBlue]

I happen to be the one shagnos speaks of. I can tell everyone here first hand my experience turning my 09 fx nytro engine backwards while doing primary clutching. Anyone who has any experience with overhead cam engines knows there is a stationary chain guide and a tensioner chain guide, when rotated backwards the slack side or tensioner chain guide forces the hyd tensioner back (oh and I know it has a mechanical lock so it cant fully depress) but it did. Stay with me, now that the chain is completely slacked, it balled up leaving crank chain sprocket wedging the links between the lower portion of the stationary guide and sprocket, breaking the guide. So I removed the engine and replaced the timing chain components, the new guides were totally different then the original ones. The replacements were longer and had a different curve at the crank ends so that even when the timing chain was slack the links could not ball up between the sprocket and guides.
http://ty4stroke.com/threads/cams-keep-jumping-out-of-time.98452/#post-873375

Is this only on the 998 motor. What about a apex or vector motor

 

[ateick]

Just a thought but you've run this and while it runs like #*$&@ it runs. Valves didn't hit anything which to me means you are off by what looks like a 1/2 tooth to 1 1/2. Do you think if you turn that primary CW again slowly and monitor any slack that might develop you could possibly use that slack to move that cam?

 

[max rolph]

actually i ran my sled for a month, you will notice no matter what it will only rev 87-8800 rpm.... fuel economy will be dwn too, if you do determine you have jumped a tooth, get the manual tentioner installed and then you never have to worry.

 

[Kuzzy]

actually i ran my sled for a month, you will notice no matter what it will only rev 87-8800 rpm.... fuel economy will be dwn too, if you do determine you have jumped a tooth, get the manual tentioner installed and then you never have to worry.

What are the adjustment intervals on the manual adjuster? Yearly? Occasional? Constant?