Thread: 4 speed engine case questions

Hello Everyone,
I am trying to bring back to life a 1971 H model bike I purchased last summer.
The first problem I have ran into is the top of the left case has a chip about an inch long broken out. The break is at the top around the flywheel area. I think the last guy may have tried to remove the flywheel with out a puller.
The question is: are the left 1/2 case sections the same from a 3 speed motor?
I hate to loose my numbers, but if it will interchange I would like to swap it.
I have a parts engine off of an 1981 3 speed bike that I would like to use.
Any help would be appreciated.
Thanks,
Ranger

I think all the 6 volt cases are the same. I don't know about the latter cases. Hate to see you lose your serial # though. It might be able to be welded up and re-machined can you post a pic. of it. and If it can be welded send it to me and let me see what we can do.

Grant

Thanks for your input and offer. I hate to loose the ser.# as well. Do these cases respond to welding pretty well? I was unsure if they would take to welding. I tried to weld a lawn mower frame in high school years ago and it was unsuccessful. This break is about a quarter in wide and 1 inch long, right out of the top. It is just to the left, (looking down at it), of the slot whrere the wires come out.

Thanks again,
Ranger

Welding alum cases depends on the casting. Where yours sounds like it's broke is a non stressed area, and high up on the case away from the oil. what I would do is heat it up some and try to cook what oil and water that is in the alum out. Then Tig weld it with Argon and 4043 rod and build up that area then grind and machine it back to orignal. If your going to scrap that case side anyway, before you do send it to me and lets see what can be done.

Grant,
I will try to post a picture later, or email you one. Your right, non stress area for sure, just looks like heck and would let water and dirt, in if unrepaired. I would like to repaint and restore this bike right, so I do hate to loose the ser. number.
It sound like you are a welder, and I am not unless it is steel, and very simple.
I may take you up on the weld job, but either way. I wont junk the case.
Many thanks for your help and your wisdom.
Brad

No problem Brad, I'm not a welder by trade,but I've been doing it for over 40 yrs. lol I'm really a mold maker but welding is part of my job. We weld a lot of alum. and I've welded cases before. If you want to go that route let me know, Take care,

He Brad there is a way to repair it without welding, give me a call and i will go over the process. mark pearson 931-636-3823

Mark,

Can you give us a general overview of your repair method. I just finished the tear down of a silver tag and I noticed that the hole on the engine casing where the bottom screw for the chain guard attaches is broken away. Will probably have it welded, but always curious about alternatives. Thanks

ive searched for aluminum products for a while and finally found one that works well,I used a old case and knocked a hole in it just to see if I could repair it,it worked,also have repaired stripped threads with it,once its grinded you cant hardly notice its there.Google a product called HTS-2000,distributed by New technology products in Tampa,I paid 60$ for 1 lb and its enough to last a lifetime,good luck

Hi All,
Thanks to all who offered help, and advice on my broken case. I have not had to much time the last few nights to work on my project. THe wife's craped out so it was time to work on it. Water pump tonight, and It looks like Saturday will be spent changing an intake gasket.
Maybe Sunday, I can finish pulling it appart, and see what it looks like. I did place an order for some parts from Dr Atv tonight. I should have everything I will need now, I hope.
More to follow later
Ranger