My 66cc cracked! what do i do! clutch doesnt work properly!

[Joey]

This is a great forum! i wish i would have found it before!
Some background into the bike.
it is a chopper, with a 66cc engine, bought 2nd hand for $250 hard earned dollars..

I really need help with this guys.. please help me,

at high speeds, the engine suddenly revs up very high, and then the chain drops and the engine dies..
also when i stop and hold the clutch down it revs extremely high when its completly stopped!

Today i was riding along and my chain suddenly fell off the sprocket.. and when i checked.. the $#@# thing was CRACKED!

The crack is under the clutch clover thing where i circled..
what can i do to fix it?
or would i need a replacement engine?
or can i weld it together?

PLEASE HELP ME!
ive been running into soo many problems with this bike..

thanks guys

 

[oldtimer54]

I have the very same problem with ths same bolt hole but the casting on the motor (not the cover plate) completly broke off. Do you guys think it could be welded back on with this cheep pot metel?

 

[Joey]

Can anyone help us? cheap things.
can we glue it back on with some strong stuff?

 

[chrisme]

From what you said and the pic I get that it's just the cover that's cracked? not the block?
Just replace the cover.
And find out why your chain is jumping off. It shouldn't jump off. In the last 3000 miles on my bike since my major rebuild last winter the chain hasn't jumped off once.
It's a combination of getting the engine, idler, and rear sprocket lined up just right. Otherwise the chain will jump off, break engine parts, break spokes, etc, etc. It gets nasty pretty quick.

 

[Joey]

Ive noticed that it gets nasty pretty quick
its the block itself thats broken!
i was riding to my friends house to actually get it fixed in the first place!
anything i can do?

 

[MotorBicycleRacing]

Can anyone help us? cheap things.
can we glue it back on with some strong stuff?

A pic of your damage would help.

Glue will not work, the clutch actuator puts a lot of
force on that bolt.

Cheap, quick and dirty, put a fender washer behind the casting
so that the cover is sandwiched together with the casting.

A fender washer is a very large diameter washer with a small hole.
You can trim the top edges if you want to get fancy.
or
Make a custom shaped piece of flat 1/8" thick aluminum that matches
the shape behind the casting and bolt it together.

Maybe a bit of JB weld too ...LOL

 

[Joey]

Heres some pictures of the crack..

sorry about the quality, it was taken with my iphone


http://img837.imageshack.us/img837/1451/img0505gq.jpg

http://img714.imageshack.us/img714/5933/img0504fx.jpg

Hopefully these help

 

[Joey]

Here a pictures of the crack,

hopefully you can see it

http://img714.imageshack.us/img714/5933/img0504fx.jpg

 

[Joey]

Heres a picture of the crack,

http://img714.imageshack.us/img714/5933/img0504fx.jpg

 

[Joey]

Well,
heres a picture of the crack,

are links allowed on this forum?
i cant seem to post the links up

http:// img714.imageshack.us/ img714/5933/ img0504fx.jpg

 

[Joey]

Are links allowed in this forum?
i cant seem to be able to post images..


and i cant upload them too!

 

[chrisme]

JB weld probably won't work... I tried to use it to fix a stripped exhaust stud I was to lazy to fix... I ended up doing it the right way

 

[Joey]

Here are the pictures!



img714.image shack.us /img714/ 5933/ img0504fx. jpg

Insert http, and take spaces out

 

[MotorBicycleRacing]

You have over 3 posts so you can post images and links now.
Try again......this is to stop spammers

 

[chrisme]

http://img714.imageshack.us/img714/5933/img0504fx.jpg

OUCH! fortunately that part there doesn't actually go into the crank case. So you can probably do the fender washer thing and it'll work fine.

 

[MotorBicycleRacing]

at high speeds, the engine suddenly revs up very high, and then the chain drops and the engine dies..
also when i stop and hold the clutch down it revs extremely high when its completly stopped!

You have a massive air leak probably where the carb goes on the intake tube.

Also check the tube to cylinder head.

Put an O ring in the carb to seal
or use some sealant.

When your engine is running full choking the carb will kill the engine
IF you have no air leaks.

 

[noco]

1) replace the cover
2) align the chain....if its 410 chain(regular bike chain) replace it with the thicker 415....its way easier to keep the thicker chain on
3) fix your vacuum leak.....its probably leaking around were the carb attaches to the intake....i shoved a bunch of o rings inside mine

wow BiMoPed...i didnt want to be repetitive but i think we both responded at the same time....haha

 

[Joey]

Okey, this is what i am going to do.
get a big washer and hold it onto the rest of the motor..
align the chain!
and hopefully tune/fix my engine.
whats the best way to check if it has a air leak?

thankyou.

 

[chrisme]

While it's idling spray card cleaner at the points where it could be leaking. Engine to manifold, and manifold to carb are about the only places. If you have a leak it'll just die, or slow down the idle.

 

[mapbike]

Joey, here is the best solution I know to the broken stuff on these engiens, works great for me. Here are a couple links for ya, 1st is about the product and 2nd is a good place to order a small amount of the rods.

It's called "Alumiweld" all you need is a propane torch, a stainless steel brush and a can of Acetone and you can weld that thing right up.

Aluminum welding repair rods, weld any aluminum metal by using a Propane Torch - Alumaweld

Pack of 8 Alumiweld Aluminum Welding Rods

If you use this product right you can fix it and forget it, it's great stuff.

 

[mapbike]

But you'd better get that air leak fixed quick or the broken place will be the least of your worries.........seriously find and fix that!