Chain Nightmare

Last Night I installed my kit chain on a new Cheez HT engine and besides the chain hitting and actually binding bad on the sprocket cover (a easy fix) this is it is way worse, please read on... So I grind down the cover and actually removed a large section of the cover as it helps nothing seems to rid the binding....still binding bad...hmmm. I grind the clutch shaft raised area a ton also...still binding and rubbing in yet one more area, but where? So After examining closer there is almost 0 clearance between the front of the engine sprocket and the actual engine itself, a credit card will in no way fit to give you an Idea at how tight this is, but its not binding there, but is too close for comfort and feel it is very- very dangerous situation for future riding on this engine. Read on FYI ( I am using a CNC rear sprocket, a GT2 a frame and everything is lined up very perfectly from all 3 angles)
So eventually I find that engine sprocket side is also so close to the engine housing that the chain will not fit without grinding on the side of the engine on the side of the chain...wow, first I've seen that in 4 kits. So yes, I am pretty sure Cheez would take this engine back and exchange it, but I don't want to exchange with him as most likely Ill just get the same engine again from the same manufacture with the same casting defects. I will let him know of these 3 issues with this engine in morn. seems like someone is making copies of copies of copies will cause this type of shrinkage in castings. Anyhow...
-I just want to figure out how to fix it
. A shim or washer Under the engine sprocket to bring it out a bit away from the engine housing?
Has anyone else encountered the Chain rubbing on the actual engine casing side?
Love to hear some ideas, I have yet to remove a engine sprocket.
I can just let it rub and bind...YUCK

60weight said:

What about using BMX bike chain?

Click to expand...

Yes a heavy duty stunt BMX chain would work. I think Ill need to address a multitude of issues as is usually the case with chain problems. Clutch adjustment, better chain( ill try a 41 chain first from hardware store. )
I play more with rear hub spacers. I have a feeling that the cheaper the chain the more likely it will kink? We were going thru a chain of events with my sons cranbrook and found out that the spring tensioner he had put on jammed in his case during bump start and jerked
..his engine slightly sideways. We didn't notice but the bike did,as his chain derailed after re installing his chain.
These chains are an art as they can be skewed slightly in so many ways. Chains certainly separate the newbies from the experts.
Thanks for the suggestions. I will probably mess up the clutch adjustment and shaft adjustment but no better way to learn then messing up.

Ill check that flower nut for scrapes too and follow up what I find when its solved.

cannonball2 said:

I run only BMX chains

They are so much easier to deal with. They fit the stock CG sprockets perfectly as they were originally designed for bike chains. They require less frame clearance. You have to have the thinner front sprocket to make this work.

The wider chains have a good bit of side to side play and derail easier.
This only applies if the stock sprockets are used. The wider rear sprockets are made for the wider chains and work well with them.

I havent run the BMX on a larger engine build but will have one on my Briggs 3hp shifter. This should put it to the test.

Click to expand...

Good to know this. Is there a good source or link for a skinny front sprocket?
and is the front sprocket hard to replace?
Thanks in advance CB 2

cool animated vid, very simplified for sure.

cannonball2 said:

Here a link to the sprocket. I have bought several from this seller.

They are pretty easy to change, just use the puller that came with the engine kit.

http://www.ebay.com/itm/THIN-10-Too...ash=item35f50cef0b:g:tRoAAOSw2s1UsXSv&vxp=mtr

Click to expand...

Thanks for the link. He is a good seller, have gotten stuff from him. Wondering if you have to change the front sprocket to use a 41 chain though as my son just put started install 41 chain on his Ca motorbike engine that is installed on his Cranbrook... if so I better warn him. In comparing the 41 chain to the 415 it is just not as high or thick, but width and length of the links looked the same, if that makes sense?

Cannonball2, I thought 41 and 410 chain were the same...wrong assumption here. I'm also confused as the 415 chain is the same width as the new 41 I bought. The 41 is just not as high as the 415 that came in the kit... Am I missing something here? id take pictures but I don't want to be covered head to toe in waxy grease at the moment, hehe.
Thanks for the picts of the sprocket and chains that will help many of us.

I finally had some time to get back to the new Gt2a build and my chain nightmare, to find out why I have severe metal to metal grinding and why my chain gets too loose and too tight on one revolution. I removed both the sprocket cover and the clutch cover to have a another go at finding out what the heck is grinding so severely. First I inspected the back of the tear drop shaped clutch cover first and whoaaa it had huge, deep grooves cut into it with a distinct spirograph pattern. Ok what's causing this bit the 2 clutch plate guide pins that appear to be sticking out 3/8 of an inch beyond the round plate. 10 min of the cut off grinder and they were the correct length. Somebody tell me how this PK80 left like this. I tweaked the clutch pressure plate flower nut and reinstalled the clutch cover and now even the flower set screw is still rubbing. Get the leather sledge out and a few swings and I bowed the cover out slightly so its all good and smooth except the chain is getting tight and loose using a CNC sprocket from Bikeberry . This CNC sprocket actually appears out of round when I visually watch it... Looks like a slight but noticable cam lope. Is this even possible...looks like it is... or were the 3 holes drilled off center where the sprocket attaches to the hub clamp...hmm... More on this later as I have to conduct that investigation next... stay tuned.
the Chain Nightmare continues.