Chain and Sprocket Troubles

[Arrowking]

So I made a few changes to my cart. The one that is giving me trouble is switching from a 64t to 54t sprocket. I did not think it through but when I put it on the chain is now too long. Well I got around that problem by using an idler pulley that's on my kart. Problem is this pulley has a loose fit to the kart frame. To remedy this I used the spring that was with the pulley(I do not remember how it was put on). The alignment isn't perfect though and the chain pops off after going over a certain RPM(around 3000).How would you fix this?

Also I put in a Dyno CL-1M-Improved cam in the predator. It runs fine, but now the recoil starter is very hard to use. Seems I've read some about these cams not having a compression release? Is this correct? I can live with the harder pull, but would like to improve it if possible.

 

[ML-TOYS]

just open the master link and then cut the chain shorter

 

[Arrowking]

That's thing. My chain doesn't have a master link. Guess I'm going to have to get a chain breaker?

 

[Beach Bum]

Unless you plan to go back to the 64t sprocket, and use the same chain, then I'd shorten the chain to fit the 54t sprocket.

It's very annoying when a chain won't stay on.

 

[Doc Sprocket]

Did you put the camshaft in yourself, or have a shop do it? If there's no compression relief on the new cam, you'd likely have seen it. It would be good to know if it actually has it or not.

Meanwhile, the best you can do is adjust the valve lash to spec. If there's no compression relief, starting will not get any easier. But don't worry- once you have the technique down, it's not a big deal.

Regarding the chain- get yourself a chain breaker and a master link. Do away with the tensioner and make sure everything is both aligned and square- using a straightedge.

 

[Arrowking]

If the compression release is the mechanism with the springs on the cam then this cam did have it. I put the cam in myself. Slid the old one out and put the new in. Everything cleared. I've started it a few times and you're right it did get easier. I'll check the valve lash once I get a set of feeler gauges.

Doesn't having a master link introduce a weak point on the chain?

 

[Doc Sprocket]

If the compression release is the mechanism with the springs on the cam then this cam did have it. I put the cam in myself. Slid the old one out and put the new in. Everything cleared. I've started it a few times and you're right it did get easier. I'll check the valve lash once I get a set of feeler gauges.

You mean you did that WITHOUT setting the valve lash to spec (using a feeler gauge)???

Doesn't having a master link introduce a weak point on the chain?

Nothing you'll ever notice. It's like having a rope that will pull 10,000lbs, connected to a rope that will pull 8,000lbs- and you're only pulling 500lbs.

 

[Arrowking]

Yes I did. Figured it would ok for now because the valve train has never been messed with. On a scale of 1-10, how bad did I screw up?

I'll put in a master link then.

 

[OzFab]

Yes I did. Figured it would ok for now because the valve train has never been messed with. On a scale of 1-10, how bad did I screw up?

I'll put in a master link then.

That the thing though, you did mess with the valve train by replacing the cam.

Don't panic, it's not a total disaster, maybe a 1 or 2, no major harm done; just adjust the valve lash before you go any further

 

[Arrowking]

Ok, that's a relief! I have feeler gauges on the way from Mcmaster Carr!

 

[Doc Sprocket]

I'll second Fab's comments. Basically, because we can pretty much GUARANTEE that the new cam isn't within .001"-.002" as compared to the original, you MUST set the lash again. I don't think you're looking at any kind of damage. Within a reasonable range, too little lash will result in slight loss of compression- too much will negate the compression relief, and possibly retard valve timing slightly.

 

[OzFab]

In simple terms, a new cam will have more lift than an old worn one

 

[Doc Sprocket]

That, yes- and- it's pretty much a money-back guarantee that the base profile won't exactly match the original.

 

[Arrowking]

Thanks guys, much appreciated!

 

[zbuck]

Did you buy the cam from Dyno or used? If from Dyno it should have had a cam card with suggested valve lash settings.

 

[Arrowking]

Yes I have the Dyno cam card. The gauges are coming Monday!