Problem with Flywheel

[matto321]

Hello,
I am new to this forum, my name is Matt and I owne a 1979 Suzuki Ds100 and I have not gotten it running yet. I have owned many dirtbikes and many atvs.
Okay here is my problem, I had to put a new keyway in and I took off the flywheel ( it was really loose ) and then I relised the the threads on the Crankshaft were striped and really msessed up. and I dont know what to do to fix that so I can finally get this thing running( because its really getting on my nerves ). I Have tried useing a tapp to fix the threads and then it didnt work so I tried a smaller tapp and the metal of the crank was to hard. so does anyone have any idea how I could fix This I don't have a welder so anything really like that. So please Give me some ideas to fix this problem. I am really getting tired of working on this. And Also I want to know if anyone knows anytips on getting this running good. I have new spark pluggs I have cleaned the carberator. and Thats about it.

 

[jason33]

i think you need a die- its a nut that goes on it not a bolt-
chase the threads again-,or mabe a standerd thread chase if its that bad-new nut,and a lot of red lock tight- let it dry-
i really dont think jb weld will help more than the red locktight-
if the threads are that bad-? i dunno
if you really love it you could take the crank out and have it welded and re threaded- or replace the crank

 

[whenfoxforks-ruled]

What size die did you thread on the crank,try to thread!

 

[matto321]

i believe 7/16, because It was the closest one that would fit.

 

[SpeedyManiac]

You need the proper size die. Get a caliper (vernier or digital) and a thread pitch gauge to determine what thread is on there. Once you have the thread (diameter and pitch), get the appropriate die to clean up the threads.

I'm guessing though that the threads are going to be beyond repair if you've used other dies on it. You're next option is to machine the end of the shaft down and use a smaller die to cut a new thread, then get a matching nut. The problem with this is the shaft is most likely heat treated (hardened, which is why you had trouble already) so if you machine the shaft down, you'll lose the hardness and probably end up with shaft failure down the road.

Another option is to weld the flywheel on, but unless you or somebody you know is a VERY skilled welder, I wouldn't recommend this. Welding + crankshafts = unbalanced crank = engine disaster.

 

[Rotorranch]

The right size die and a new, correct sized nut, and you may yet be able to salvage it. If you didn't foul it up too bad with the 7/16 die.

Jap bikes = metric hardware.

Rotor

 

[matto321]

yeah I know jap bikes= metric hardware but Let me tell you this hardly anything on this bike is metric. I have got a another engine just like it. but I have no Idea really what to do to swap the cranks. It doesnt seem to hard. but Is it possible to change the crank with out having to rebuild the whole engine or is it possible to pull it apart and put the new one is with out having to replace anything else. Any tips will really be appreated. also if anyone could tell me the easiest way to change it Please tell me

 

[76GMC1500]

I have a hard time believing that bike has standard hardware, it must be metric. The crank is probably damaged beyond repair after running a standard die on it. If you have another engine, why not swap that one out instead of trying to replace the crank in the current one?

 

[matto321]

the other engine is missing the top end. and it doesnt run

 

[Rotorranch]

Oh well...that explains everything! :whoa:

I never have got an engine to run with no top end. :bang:

Maybe use the top end off the engine with the screwed crank? :nod:

You do have a manual for the bike, right?

Rotor

 

[matto321]

Yeah Well I decide just to sell the bike, I have done a lot of work to the bike but I don't have time to work on it anymore. It would make someone a good bike if they put a little work into it. I also have many extra parts for it. I also want to get another one that needs less work ( or no work at all ). If anyone is intrested just reply!