Modern Vespa

bottom of engine. flywheel side.
should be easy weld right?

Should be straightforward repair.

Hey, what's with all the gouge marks? Are you using screw drivers to pry open your cases?

has any one tried using this hts2000 as an alternative to tig welding aluminium engine cases
not sure i'd use it on a cylinder or head
search you tube for hts 2000 aluminium brazing
interesting all the same i think

i made a fuel tank with Easyweld (aluminium brazing) so repairing this crack should be no problem. Brush with an stainless steel brush, and start brazing. You need a big flame to heat up the case. I use a propane burner to heat up the part and then with a smaller flame do the brazing.

Sara

no, i haven't been screwdriver-ing the cases but apparently someone has.
this poor motor has been rode hard, opened with a hammer and fuggled-up pretty badly.
im gonna use a little emory to clean up the gasket surfaces.
i just noticed the crack after cleaning the cases in the parts washer and scraping the old gaskets.

im almost at a point where im ready to cut my losses and find a new engine, i haven't had much luck with it...

its been a sad saga...
the saga of my smallframe engine rebuild

sara, ill look into that aluminum repair, its a small crack. do you have to get the case up to a certain temperature? would a hand held propane torch do it?

handheld will do. Just watch the temperature, aluminium melts without much warning!
I use also a sharpend stainless spoke, to scratch in the melting bath.

Good luck

Sara

Cheap, easy job for an experienced welder, aluminium melts at 600 degrees, an alloy may melt at a lesser temp. It wouldnt be something i would attempt for a first job. Upto you.

*edit* you could on the other hand, cross file and lap the repaired case surface flat and smooth it yourself, as that would take the most time and of the repair be the most important part. The use of bearing blue or a vivid marker to show high spots would be useful.

cheers

thanks guys (n dolls)
im gonna send it out to get welded and have the cylinder matched to the cases while its out...

good! It is an easy weld, but since it involves the gasket face, it will need to be surfaced correctly or it will leak oil and be an ever present reminder of all of the issues with the rebuild instead of letting you enjoy riding it!

meh on the welding. this looks like a job for JB weld.

seriously. clean it up really good with brake clean, take a little file and gouge a little v up in there, clean it all really good again with alcohol and lay some JB on there, use a razor blade to clear the excess off the gasket face and call it done.

best,
-greasy

I agree JB Weld should work, but first drill a small hole thru at the end of the crack so it doesn't migrate.

+1 on what voodoo said . J B works a lot better than you may think , I had a broken clutch adjustment bracket for the screw that was broken off the case . I used a screw and some J B thinking it would last maybe until I find another case rode the scoot for about another year .

JB weld is a good idea. Maybe not a completely permanent fix but should last a long time. I have seen crazy porting jobs patched with JB hold up for years, amazing given they have way less support than what you have here and the transfer area sees pressure changes and gasoline, etc.

Get super small syringes and inject the mixed epoxy into the crack after prepping it like greasy said!

My guess is the case was cracked while trying to pry the thing open. Chances are even with the crack its not leaking. If you weld it the chances of warping the case is there. Brazing is a better option. Less heat. If it were me. I'd v it out with a dremel tool then use some duramix on it. Duramix is a 3m brand of epoxy kinda like jbweld.

I didn't see a need to start a new tread since this one is very close to my problem.

I'm working on a Sprint Veloce engine. It seems the PO tried to crack open the engine and knocked a chip out of the case. In the picture below, you can see the "U" shape chip on the top of the case.



Can this case be used or should I purchase a entire new case? Fixable?????

thats just the leaf blower part

Just leave it, it'll be fine. Worst comes to worst maybe you could glue a bit of similar plastic to the cylinder cowl.

Of course, this doesn't mean the previous owner is off the hook for a smack in the mouth.