Finally got a Yamaha...

So I just got around to putting it all back together today. I did go ahead and change the float needles/jets. Also replaced the washers and o-rings on the fuel screw, and reset those to 1-3/4 turns.

Started nicely once the bowls filled up. Much less smoke/fumes at idle. Responds well to throttle. Sprayed starting fluid around the manifold/reed cage area to see if there were any significant leaks, with no effect. Wonder why those fuel screws were so open? Perhaps somebody tried to compensate for dirty pilots they were too lazy/afraid/cheap to clean? It really smoked and fumed like mad before this cleaning and adjustment.

Trying to decide whether to attack the skid or the clutch next. Decisions, decisions! I wish I had more free time to do this stuff. I love working on sleds, and taking the time to get things right.
 
SRX/Viper reed cages will drop right in there. They're probably somewhere @ 10% more area for the reeds to draw air. And they do make a difference. Especially if you put fresh Carbon Tech reeds in. If you get the SRX/Viper cages, you'd obviously need SRX/Viper reeds. 370LT
http://www.carbontech.com/snow/yamaha.html
You should pull the reeds just to check & see if there are cracks in the reed stoppers.
 
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Shoot. I went back to the first page and noticed you have aftermarket reeds/cages. Anywho, take the skid out first. There is likely some welding that needs to get taken care of before the clutch gets fine tuned.
This is where I've been getting my bearings from.
http://www.acerracing.com
6205 & 6004 are your common skid bearings. Also, as long as your skid is out go ahead and change your speedo side jackshaft bearing. It'll be good piece of mind. Plus you don't want the wife on a broke down sled. If she's not happy, your not far behind.
 
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http://www.totallyamaha.com/snowmobiles/AAATuning Chart/Tuning_Chart.htm
The third set-up from the top is Vmaxjohns. The second from the bottom is mine. They're virtually identical. The weight profile is the same. But they weigh differently. That's the reason for the rivet differences. I used his set-up but had 8ca's already on hand. So I adjusted and tested accordingly.
 
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Sounds like you have a plan. I own a 1995 Vmax 600 and it is one of the best sleds I have ever owned - never had an issue with it. Happy sledding
 
Dusting off this old thread to see if I can get a little advice/guidance.

Just actually got the chance to ride this sled (99 V-Max 500) on the snow for the first time and realizing that I am having some real issue with driveline drag somewhere. Feels like the brake is on, but it's not. Also getting a little ratcheting at takeoff and a whiff of belt.

I know the spec for track tension is very tight; I know I'm not any tighter than the spec, but also not very loose. I had the skid out and replaced the rear idlers in the fall of '15; none of the other skid idlers were bad by my own assessment.

Thinking I am going to put the back end on the lift and loosen the track a bunch and see how it turns by hand with the belt removed. It was quite hard to turn by hand with the track tensioned, as I recall from last fall.

My theory is that I may have a driveshaft bearing problem that is causing the resistance and resulting in some chain skipping which gives the ratcheting sensation.

Question: How hard/impossible is it to remove the driveshaft without dropping the skid? I do pretty much all this work solo, and I don't relish installing the skid again if I can avoid it.

Other info: track that came on the sled is a new looking Kimpex ultimate traction and when I had the skid out I had replaced the rear shock, hyfax and the previously mentioned rear idlers (all three). Also just this week replaced the rear shock tension rod bushings which were shot.
 
Roll up your sleeves and dig in pull the skid go thru everything, do your bearings and check your chain case bearings too. Then you will be good to go. Don't forget that the jackshaft also has bearings. Peace of mind for a few hundred bucks.

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Key to the skid is to loosen the bolts almost all the way out of the transfer rods makes it a lot easier.

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xsivhp said:
Roll up your sleeves and dig in pull the skid go thru everything, do your bearings and check your chain case bearings too. Then you will be good to go. Don't forget that the jackshaft also has bearings. Peace of mind for a few hundred bucks.

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Click to expand...

So I did go through the skid already last fall. All the bearings were good except for the rears, which I replaced.

I'll post back with what I find going forward.
 
Schocker65 said:
So I did go through the skid already last fall. All the bearings were good except for the rears, which I replaced.

I'll post back with what I find going forward.
Click to expand...
Never hurts to check all the little plastic bushings and grease it up. Having air tools makes it quite a bit easier and faster.

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So I cracked open the chaincase and pulled out the guts. All looked fine, but the chain is a bit stretched. I'll plan to replace it for next season if I keep the sled.

Noticed a fair amount of brake drag when turning the driven clutch by hand with the chain out, so I took out the brake pads and lubed all the sliding points where the pads interface with the caliper/pin/clips. This seemed to make a noticeable difference in the amount of brake drag I could feel when turning the jackshaft with the clutch. With the brake pads out, by the way, the jack shaft was freewheeling and quiet.

The track, by the way, was far easier to spin when loose with the chain out, as you would expect, but it still acted like it had a "stiff" spot or two that made for some occasional resistance.

While I had the bearing on the clutch side exposed, I turned the outer shell by hand a bit, and it felt ok (not loose or coarse), so I popped off the cover and re-packed it as there wasn't much grease in there.

After all that, I buttoned everything up and re-tensioned the track. Went to turn by hand and it was even harder than it had been when I started all this. Crap!!!

Loosened the rear axle and backed off the tensioning by two full turns on both sides and turned the track some more. Significantly easier, maybe better than before I started. So, tightened the axle and took it for a ride.

Heavy resistance at first - didn't even want to move. Got it going and after a couple of miles the resistance seemed to be going away, with some occasional re-occurrence. Really odd. One thing that was gone completely, though, was the ratcheting that I was feeling before.

By the time I parked it, it seemed close to normal, from a rolling resistance standpoint. Still a bit sticky.

Thinking that since the ratcheting went away at a lower track tension than I had before, I am going to try to back it off some more and see if I get any more benefit without inducing a "new" ratcheting problem. I can't believe the tension that Yamaha specs for these sleds. Maybe that tension spec and the Kimpex track aren't a good mix?

I am determined to fix this!
 
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Ok, so I did loosen the track some more, and it did not seem to make a difference from a drag standpoint. Still the ratcheting is gone, however.

At this point, it seems that there is an intermittent drag that really feels like the brake is being applied. It comes and goes, so not sure what I've got going on. I have laid my hand on the caliper after riding and it is barely warm. Not thinking that's the problem.
Even when cruising at 30 or so it just starts happening and I need to give extra throttle to maintain speed. There is no noise or vibration that I am perceiving that I can link to this. The drag is present intermittently at other speeds as well or while taking off from a standstill at times. Am I wrong to think that I should feel some vibes or hear something if it was a driveshaft bearing? This is irksome.
 
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