Engine blown already?

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EricM · #21 Post by **EricM** » Sun Sep 28, 2003 8:15 pm

So that is why it says in the other thread that it costs $600 to get a crank redone. If that is the case i will be buying a bike engine. I could probably get about a 95 cr500 or kx500 cheaper than fixing my engine.

cannondale27 · #22 Post by **cannondale27** » Sun Sep 28, 2003 8:28 pm

I agree $600 is alot of money but he is replacing parts etc. AND giving a warranty.
You arent even sure that your crank is bad yet.Just take it one step at a time and dont get to worked up about it.2 strokes blow up all the time.When they go if it costs less than $600 you are lucky even if it is only a $500bike.

WJR · #23 Post by **WJR** » Sun Sep 28, 2003 9:19 pm

600 bucks is a lot of money, but before scrapping your engine, maybe give Big Winky a call. He is doing more to these cranks than he has listed in the other post. I am out some big dough for my engine, but I am almost certain the crank is the heart of the problem. If you're lucky, when you tear your engine down, you will find its not the crank, but if it is the crank, maybe the rest of it is intact. I lost my case, pisotn/sleeve, crank, crank cart plate, oil pressure pump, scavenge pump. But, it was all due to a common root--the crank failing and vibraiting everything to death. There are a lot engines out there that are running strong after many hours, and that gives me hope for the overall design. Good luck.

WJR

Big Winky · #24 Post by **Big Winky** » Mon Sep 29, 2003 12:34 pm

I agree that $600 sounds like alot of money, but when you start thinking about how the crank is designed, the amount of time that went in to just figuring out a way to get the crank apart without damaging it, the cost of custom rods, the time finding a suitable rod bearing, the repairing of the rod journal, the fitting, the straightening, all the while working to under .001 of an inch tolerance. I'm not getting rich here. The C-dale crank is NOT like other cranks you've come across (I wish it was). Just the design of the crank, although a good design, makes it difficult to service at best for our company and downright impossible for the average mechanic to attempt. AND we also are addressing a problem due to the vendor's quality control which we were very lucky to discover, which would have, if gone unnoticed resulted in the failure of our cranks also, and no, I'm not saying what the problem is to anyone, except possibly the Montgomery's lawyers as I feel their vendor really screwed them and were instrumental in the demise of our favorite company. And remember...you are getting a crank in return that is no longer something that you'll be thinking about if, when, or where is it going to go south on you. As far as putting a bike motor in the chassis goes.... My son put a YZF motor in a moto chassis and that wasn't a cheap date either not including the cost of the motor.

EricM · #25 Post by **EricM** » Sat Oct 11, 2003 8:54 pm

I finally got to tear down my engine and i ran into a big problem. You have to spin the crank to take the piston out and my crank is locked up. I put a 2' breaker bar on it and it still wont spin, so how do i get the thing apart with the crank stuck?

Big Winky · #26 Post by **Big Winky** » Sun Oct 12, 2003 12:23 pm

Eric,
yeppers, the rod bearing is gone. I haven't found a crank yet that I couldn't force to turn (try moving it both directions, alternate from one side to the other end of crank) you should be able to get it to move.
Jim

cannondale27 · #27 Post by **cannondale27** » Sun Oct 12, 2003 7:58 pm

If you have tried everything you will have to just pull the sleeve the hardway.Visegrip on the lip going around and pulling sleeve will come out but will be junk.Then if piston is to high to line up pin with access hole use a rubber hammer to pound piston down.Dont knick the case piston might be shot after doing this.

EricM · #28 Post by **EricM** » Sun Oct 12, 2003 11:26 pm

I beat on the piston with a piece of wood and a hammer and it broke the crank loose (it was really stuck good) then everything came apart fine. Now the problem is finding the funding to fix it (I am a broke mechanical engineering student and I can't find a job).