Installing a new right crankcase

KHPower · Post by **KHPower** » Thu Jun 28, 2007 8:46 am

I few years ago , a friend of mine wiped out on my scooter and as a result the muffler mount on my right crankcase cracked. A few weeks ago I took the scooter out of storage to repair it thinking I could just braze aluminum onto the crack and all would be good. Well after clamping the muffler to the crankcase so many times to braze it the whole lip that the muffler mounts to on the crankcase broke completely off.
I took my bike to the mechanic to see how much he would charge to put a new starter on(silly me) and he said it would be 180 bucks including the starter. Then I asked him if he noticed the crack I had on the muffler mount and he said"never mind you are going to need a new motor case because he thought that the block itself was cracked and he said it was a miracle the thing even ran. I didnt want to argue with him because I knew that the block wasnt cracked it was just the muffler mount. Anyways , the scooter purrs like a kitten and it runs fine , however , when you get to 20mph it starts to shake and rattle and what not. I basicly have the muffler mounted to the head and the broken piece with the pulse generator mounted to the muffler so the scoot will run. The pictures below show what I am talking about. I wanna relpace the right side crankcase because I can get the part fo 50 shipped. I am worried however that after I replace it , it probablly wont run and I dont have the kind of money to pay a mechanic the kind of coin need for a rebuild.
I would love to just do without a muffler for awhile but the pulse generator pickup is the only reason the mufflers on there and I dont know how the scoot would run without it. I asked many if I could just weld it but everyone says it would be easier to just replace the motor. I dont wanna have to do that. I like the motor I have now , kinda sentimenal
Any ideas? is it really difficult to replace the right side crank case? What does the pulse generator pick-up do? any help would be great!
Pictures below

KHPower · Post by **KHPower** » Thu Jun 28, 2007 8:57 am

In addition , the last picture you can see a wire hanging down , that is the new wire for the pulse generator pick-up . I burned the originaly wire while trying to braze , but its all good now and today I will shorten the wire and do some soldering

I guess the brazing didnt work because I needed MAPP gas for my torch , also I burned the my drain tube in the process , but that is replaced.
I seen some of those brazing rods that seem to do just magic when melted properly but I am afraid to get the crankcase that hot in fear of ruining something inside.

mousewheels · Post by **mousewheels** » Thu Jun 28, 2007 3:00 pm

Pulse generator pickup is the timing signal input to the CDI. On its signal the CDI will discharge to the coil and generate a spark.

Kenny_McCormic · Post by **Kenny_McCormic** » Thu Jun 28, 2007 3:08 pm

im pretty sure you cant braze alluminum. Alumiloy is your friend http://www.shop.com/op/~WELDING_ROD_KIT ... sourceid=3

chevyguyjay · Post by **chevyguyjay** » Thu Jun 28, 2007 3:41 pm

wow, those r some interesting pics.

KHPower · Post by **KHPower** » Thu Jun 28, 2007 3:44 pm

Well , I did try brazing with aluminum rods purchased from Menards. I do not know if they are the same as the ones you listed but all I know is they didnt melt like the ones you see on the net. For example do any of you think this stuff will work? and do you think I can do this with the crankshaft still on the bike?
check the video on this site , there is some other rods like this I have found elsewhere but here is a good example
http://durafix.com

KHPower · Post by **KHPower** » Thu Jun 28, 2007 3:54 pm

chevyguyjay wrote: wow, those r some interesting pics.

The damage or how the bike looks? It actually cleaned up pretty nice

MySpree · Post by **MySpree** » Thu Jun 28, 2007 7:41 pm

i can rebuild it with a new case for 75

Post by **noiseguy** » Thu Jun 28, 2007 10:38 pm

I'd take up Myspree on that offer.

I can't believe that it runs that way either.

Cast aluminum is very difficult to weld correctly, but it could be done.

KHPower · Post by **KHPower** » Thu Jun 28, 2007 10:59 pm

Yeah , it runs very good actually

like I said the crack was just on the mount not on the block so the compression is there and nothing internal is damaged. The muffler is installed to the head it just isnt mounted to the case and the pulse generator is in the right spot because the broken case peice is bolted to the muffler. High speeds is the only thing bad due to the vibration , but I keep it around 15mph.

Myspree.
I sent you a PM .

chevyguyjay · Post by **chevyguyjay** » Fri Jun 29, 2007 7:37 am

its a frickin' honda.....they run no matter what abuse u do to em.

Post by **noiseguy** » Fri Jun 29, 2007 12:36 pm

OK... well you need to get the muffler hooked to the engine case at another point, or replace the case side. You will break (not if, when) the muffler at the head, and if you're really unlucky you'll break the jug as well.

KHPower · Post by **KHPower** » Fri Jun 29, 2007 12:59 pm

Sorry , but what is the jug?

I realize that it could do alot of damge not properly mounted and it sucks and I think Ill take Myspree up on that.
I tried finding another point to mount it , but I can not find one. I went to the hardware store and bought a huge hose clamp but I just cant get anything to work.

KHPower · Post by **KHPower** » Fri Jun 29, 2007 2:20 pm

Also , do you guys think that because my muffler is not mounted properly that is causing the excessive viration and shaking/noise? I tightened the engine mounting bolts a little today but noticed that they are are pretty solid , and additionally my tire is a little wobbly. but I am pretty sure that is not causing the noise and vibration at higher speeds.

HuskieMobileMan · Post by **HuskieMobileMan** » Fri Jun 29, 2007 3:00 pm

KHPower wrote:Also , do you guys think that because my muffler is not mounted properly that is causing the excessive viration and shaking/noise? I tightened the engine mounting bolts a little today but noticed that they are are pretty solid , and additionally my tire is a little wobbly. but I am pretty sure that is not causing the noise and vibration at higher speeds.

Yes. It needs to be mounted to the case.