Primary chain tension

How much slack? Say from the outer case bolt how much movement up and down.?
Can't find it in the manual

Cheers
Dkt

Dkt26 said:

Can't find it in the manual

Click to expand...

http://britmoto.com/manuals/Manuals/750_man.pdf
Section C41.6

Ah thanks heaps.
Tension was good but it rattles terribly. Gearbox/clutch shaft has some oblong drift. Sort of slightly oval.
Main shaft in gearbox is 12mths old.
Chain End play at back of clutch sprocket is 2-3mm.
Is it time for a maney belt drive?

Uh Uh, its time for another ball vs roller bearing post plus everything else in tranny as a belt will not stay on with any wobble in the clutch basket and chain will rattle.

I found this helpful from Mike, print it out and put it in your book.

"I've always found it difficult to measure the total up-and-down play of the chain, because you have to wiggle the chain up and down somehow and also measure how much it's moving, all through a small hole. An easier way is to measure a tight chain compared to a slack chain, since this is half the total up-and-down play. To do this, make two marks 3/16" apart [not 3/8"] on the end of a stick or piece of paper. Then put the bike on the centerstand and the gearbox in 4th, and lie on the ground next to the primary.

Now, if you move the rear tire in the forward direction with your foot, the bottom of the chain tightens and you get all the slack on top. If you move the rear tire in the backward direction, all the slack is on the bottom and the top is tight. So pick out some feature on the chain (top of link, bottom of link, rivet, etc.) , and compare it to the two marks as you move the wheel back and forth. You can easily see how much it's moving compared with the two marks and loosen the chain appropriately. (BUT DON'T OVERSHOOT! If you get it TOO loose, you have to tighten it and start all over again).

Once the tight chain/slack chain play is 3/16", you know the total up and down play is 3/8". I also try to check it later when the engine is really hot. You can do this at the side of the road, and there should be at least SOME play then, or it needs to be a little looser.
Mike Taglieri"

Dave
69S

make sure the clutch nut is tight before you fool with the chain tension, often the stock locking tab washer will compress and make the nut loose which will increase clutch wobble and decrease chain tension (learned this the hard way myself)

Gearbox/clutch shaft has some oblong drift. Sort of slightly oval.

Click to expand...

Only takes one over tight event to cause this, or just wear over time. May still rattle with chain tension right, if ya can figure out where in the oblong off centering to set final tension at.

Thanks for the responses. U wiil have a crack on the weekend but I think the chain is flogged. I am going to upgrade to a belt ASAP.
The oblong spin is only a mm or so so I am hopefully the belt upgrade will be fine.
I think when I sent it to who I thought was a reputable performance engine builder, a number of things went wrong including the exclusion of most of my mk111 ISP fittings. Primary now don't seal etc etc.
Never again
Dkt

The oblong spin is only a mm or so so I am hopefully the belt upgrade will be fine.

Click to expand...

If your measure is not just a flippant tease, you may learn a silly mm to a belt is as good as a mile for staying on, which depends on stable clutch basket. You're only easy way to go is new chain, which can tolerate clutch wobble a good bit but does decrease chain life.

Seriously??
Shit!!!
I'll drop the Primary cover again and load a clip for you to look.
I havnt measured the oblongness (artistic license) with a Micrometer or anything so it is my guess but it is noticible.
Will be back in a day or so

Cheers
Dkt

Belts pulley alignment should be done w/o the front pulley side plates on using gear box cradle slot adjuster till turning the primary leaves belt tracking centered on clutch w/o walking in or out on clutch teeth. When ya see how little out of line it takes and how few turns for belt to walk itself into primary case or right off the clutch basket, your mood will drop greatly on the complete going thought the gear box needs to keep a belt running - or UGh, belt ends up all packed up melted and frayed around front items of primary. Only easy cheap way to go with any detectable clutch wobble is back to the oil chain gang.

Yea a , as per other Whineing fred , Put your hoof on the REAR drive chain , while setting primary .( try off and on )

One Finger on the top run off primary , fru the little inspection hole . ' Bother ' .

The Plot Thickens .

As promised
http://www.youtube.com/watch?v=H7dcTOOi ... ata_player