Update on '86 - got it running sort of

[VMAXMARK]

The last thread about my sled was getting pretty long so I thought I'd statrt a new one. This is the one with the widened front end, slide rail lubrication, primer and other things that made me think it may have been raced at one time. I bought it without checking it out real well and got it home and it wouldnt start. Turns out the motor was really flooded from hauling it home in the back of my truck with ass end up on the tailgate and by using the primer too much. I removed the pipes and plugs and blew air in the motor too clean it out. It took about 20 pulls but it finally started.

It runs ok but it idles low and hesitates on acceleration and it isnt nearly as snappy as my '85.

The carbs were supposedly rebuilt so I didnt take them off.

It does have the wrong primary clutch on it - it's an older Yamaha clutch. Would this cause the motor to run bad? I understand it will deffinatly affect the driveability but what about the actual running of the motor?
(I have a replacement clutch coming for it)

Here is a video of it running:

http://s151.photobucket.com/albums/s152 ... H00276.mp4

[VMAXMARK]

here is the sled after cleaning it up. I bought a new windshield and still needs a seat cover but it has potential if I can get it running right.

[VMAXMARK]

here is a picture of the clutch- can someone tell me what puller I'll need to get it off?

[Vmax540]

It runs ok but it idles low and hesitates on acceleration and it isnt nearly as snappy as my '85.

The carbs were supposedly rebuilt so I didnt take them off.

It does have the wrong primary clutch on it - it's an older Yamaha clutch. Would this cause the motor to run bad? I understand it will deffinatly affect the driveability but what about the actual running of the motor?
(I have a replacement clutch coming for it)

With that old Yamaha clutch you have to look at the engagement and shift Rpm's in which I would be surprised if it is even close and yes, the hesitation(bog) and snappyness is more than likely all in the clutching. I would never trust anyone doing the carb jetting or cleaning without looking for myself.

Here is a video of it running:

http://s151.photobucket.com/albums/s152 ... H00276.mp4

[killerklown]

One of my old 87's had a hesitation I never could fully get rid of, until it melted a piston, I tore it down and found the base of the cylinder had some damage, like it had been pried off a case once, so it messed up the base gasket causing an air leak.
Just one more thing to worry about!

[VMAXMARK]

I had some time to work on the Vmax this weekend and a I quickly found part of the reason for lack of performance- the belt was wasted and I cant believe it moved the sled as well as it did.

I also found what appears to be evidence of an exploded clutch- the frame behind the clutch is all chewed up.

I got the old YP clutch off and didnt even need a puller- it just slid right off.

I bought a replacement clutch off a supposedly good running '86 - its a Comet 108c.

I had to order a new retainer bolt and washer but is there supposed to be a spacer/washer on the back side of the clutch before I slide it on the shaft?

[VMAXMARK]

Well I just found out the special retainer washer for the clutch is discontinued- anybody know where I can get one? I believe this is special washer with a "collar" on the back side that fits inside the outer clutch cover.

Part # 8u7-17648-00-00

[Vmax540]

Mark,

Looks to me like someone done some prying on the frame/clutch ? I'm pretty sure I have a couple spacer/washer's so, send me your address and I'll send you one out tomorrow.
H 814 354-2687 W 226-1595 Later Chuck

[VMAXMARK]

Thanks Chuck- I sent you a PM.

Is there a spacer that goes on the shaft before the clutch slides on?

[Vmax540]

Thanks Chuck- I sent you a PM.

Is there a spacer that goes on the shaft before the clutch slides on?

No

[killerklown]

Description
--- WASHER
This Yamaha 8U7-17648-00-00 WASHER part is also used on these models and components:


1983 SR540G PRIMARY SHEAVE

1983 VMX540G PRIMARY SHEAVE

1984 SR540H - SRV PRIMARY SHEAVE

1984 VMX540H - VMAX PRIMARY SHEAVE

1985 VMX540J - VMAX PRIMARY SHEAVE

1986 VMX540K - VMAX PRIMARY SHEAVE

1987 VMX540L - VMAX PRIMARY SHEAVE

1990 EX570EHP - EXCITER LE (ELEC START) HIGH ALTITUDE PRIMARY SHEAVE (EX570EHP) (YAMAHA - COMET)

[killerklown]

What color spring does the new clutch have?

[VMAXMARK]

It appears to be a silver spring.

[VMAXMARK]

This Yamaha 8U7-17648-00-00 WASHER part is also used on these models and components

Thats the part number that is discontinued and not available.

[VMAXMARK]

I found more problems with the clutch I bought- two of the rollers are worn right through but the thing that really concerns me is there appear to be stress cracks on each rib around the hub on the back side of the clutch. Is this normal or is it a major failure waiting to happen?