Can I Remove Rubber Damper on Camshaft Sprocket

[Guest]

I have searched and cannot find anything on this subject. Honest!!!!!!!!

On the 550 camshaft sprockets there are two rubber dampers on each side of the sprockets. I guess they are there for the camchain to run along for quieter operation. The rubber damper on one side has the timing marks stamped into the rubber.



The damper on the other side of the sprocket has round circles stamped onto it.



I need to fit these sprockets to the 650 camshafts (which incidentally don't have these rubber parts on their sprockets) and they will not fit because the rubber dampers interfer with the 650 camshaft flange which the sprocket bolts up to. You may ask why I am putting 550 sprockets on a 650 camshaft and the answer is that the 650 sprockets have 34 teeth and I need sprockets with 30 teeth to match the 15 teeth on my crankshaft.

The flange on the 650 camshaft fits onto the sprocket where the dampers have the circles on them. Can I remove the dampers from that side of the sprocket? Should I just cut the rubber away where the interference is so they will bolt up? This way the camchain will still receive some support.

If I remove the dampers from that side should I also remove the dampers from the other side as well, keeping in mind that this one has the timing marks on it. If I remove the damper from this side is it OK to centre punch the sprocket to mark the two timing marks No. 1 & No. 2.

If I remove the rubber damper from the one side only will that set up some kind of imbalance on the sprocket. Damper on one side and not on the other.

Sorry for the tome. All helpful advice as always is really appreciated.

THANKS

[Steve]

I need to fit these sprockets to the 650 camshafts (which incidentally don't have these rubber parts on their sprockets) and they will not fit because the rubber dampers interfer with the 650 camshaft flange which the sprocket bolts up to. You may ask why I am putting 550 sprockets on a 650 camshaft and the answer is that the 650 sprockets have 34 teeth and I need sprockets with 30 teeth to match the 15 teeth on my crankshaft.

Ahh, 30 teeth, 34 teeth, it's all close enough.
Besides, the 650 cams will make so much power, the mis-match in teeth will just serve to keep the power down to a "reasonable" level.

The flange on the 650 camshaft fits onto the sprocket where the dampers have the circles on them. Can I remove the dampers from that side of the sprocket? Should I just cut the rubber away where the interference is so they will bolt up? This way the camchain will still receive some support.

If I remove the dampers from that side should I also remove the dampers from the other side as well, keeping in mind that this one has the timing marks on it. If I remove the damper from this side is it OK to centre punch the sprocket to mark the two timing marks No. 1 & No. 2.

If I remove the rubber damper from the one side only will that set up some kind of imbalance on the sprocket. Damper on one side and not on the other.

As long as you maintain the full circle, I don't think removing the rubber from one side of the sprocket would be a problem, but looking at the picture, I am wondering if maybe those circles are really the heads of some rubber 'rivets'? Personally, I would not depend on adhesive to keep them in place, so I suspect they might be extensions from the other side that lock the two pieces together. I have a sneaking suspicion that if you remove one side, the other one will come off, too.

It's just a guess, though, as I am not a mechanic and have not recently stayed at a Holiday Inn Express.

.

[GregT]

If you remove the rubber from one side, remove it from both.
It is bonded on with holes through the sprocket connecting the rubber on each side so you'll need to clean out the holes too.
Leave nothing on to possibly detatch & fall in.
I machine most off in the lathe then wire buff the residue off.
You are going to dial these cams in right ?
Put fresh timing marks on once they are dialled in.

Greg T

[Suzuki_Don]

You are going to dial these cams in right ?
Put fresh timing marks on once they are dialled in.
Greg T

Hi Greg, I had not intended to dial them in as they are standard cams. And I don't believe that slotted sprockets are available for the 550/650 motors.
How do you suggest I put fresh timing marks on the sprocket. Are they hardened steel. Can I centre punch them. What do you suggest?

[GregT]

They're not particularly hard - you can slot them with a round file - chainsaw files are excellent for the job. You can re - mark the sprockets with a good scriber once timing has been established.
Dialling in IMO should be done as you are putting the different cams in and there's no guarantee standard marks will be within cooee of right.
As someone else here says - to measure is to know.

Greg T

[Suzuki_Don]

They're not particularly hard - you can slot them with a round file - chainsaw files are excellent for the job. You can re - mark the sprockets with a good scriber once timing has been established.
Dialling in IMO should be done as you are putting the different cams in and there's no guarantee standard marks will be within cooee of right.
As someone else here says - to measure is to know.

Greg T

Greg I would like to dial them in, but as I have never done that before and don't really have the $s to spend on the fancy dial gauges, etc. which I probably will never use again, I am a bit reticent to move into that area of my lack of expertise.

Wish there was someone here in OZ that could help me dial them in using their own equipment. Might even pick up a few hp as well.

[GregT]

Don - answering you here rather than your other thread.
Yes, you have a 650 top end - used on a 550 bottom end I have no idea what the difference is in crank to cam distance - the length of chain here 550 vs 650 is the critical point as to whether the standard timing marks will work. As no one appears to know this you really should dial the cams in for safety.
Dialling in can be done without dial gauges - you say that there's a big difference in the shims, great. Set up a degree wheel on one end of the crank - a 6 in dia 360 degree protractor will do you - go see a stationers or school supplies shop. Put in on an end cylinder a pair of shims which give you big clearance - bigger the better.
Using a thin feeler gauge - .002in or so - note the points where you run out of clearance. You are only interested in calculating lobe centers - for which the answers stay the same regardless of the point in the lift you measure.
I'd probably mark the standard timing marks in pen on the sprockets, set it up and measure as above - you may be OK. Try for standard 650 lobe centers as a starting point.
This is necessarily only a quick run over the subject of dialling in cams - I'm sure there's more on here if you search.

Greg T

[Suzuki_Don]

Thanks Greg, I like you idea of finding the lobe centre. Instead of using a dial gauge use a feeler gauge instead. I have a 2.25 shim which is on the thin side of the range so I can use that. What is the rest of the process after the lobe centre is found and I assume you only do that on one lobe on each camshaft.

I checked the camchain lengths in my parts books and the 650 has 120 links and my new camchain only has 116 links. But considering I am going down from 34 teeth on the 650 sprocket to 30 teeth on the 550 sprockets then I think I should be OK.

[Mike Derrett]

Dial Gauges in Sydney

Don,

I have a mag block dial gauge in Chipping Norton you can borrow if you're willing to give it a try.
Never done it myself, always just bolted it up stock.

BR

Mike

[Suzuki_Don]

Don,

I have a mag block dial gauge in Chipping Norton you can borrow if you're willing to give it a try.
Never done it myself, always just bolted it up stock.

BR

Mike

Thanks Mike when I get around to it I might get in touch and see if I can master this new task.
Thanks again for the offer.