Straightening n Repairing Maico Fins

[Mick D]

Does anybody know how to go about this?

Or ever had any luck?

Its time for Me to have a go, and I must admit, I am a bit nervous about it

[Ji Gantor]

Hi Mick-De,
Can you post some photos of the fins.

Ji

[Ji Gantor]

Hi Mick,
The cylinder on the left, is it only that top fin that needs to be attached?
We have to attach a few broken off fins on a Bultaco head next week so I will post some images and let you know what worked and what did not work. We are going to make new fins then TIG weld them on. We hope that it will look pretty close from say a meter away. If it looks good from a foot away we will be very happy. Once the fins have been cleaned up we intend bead blasting the hole head again so the finish is the same everwhere.

Ha Ha Ha, good old Ebay sellers, "will need a small crack welding on the intake".

Ji

[paul]

mick  i got the swing arm fixed today . did you get the jetting specks

[LWC82PE]

that one is one the right with bent fins doesnt look like too much drama. The key is lots of heat but not too much so its not a job for the inexperienced. Practice on some scrap bits of alloy the same thickness to learn how to tell when its getting to the right temperature and to know when you have too much heat and its about to melt.

[GMC]

Yes, definitely practice on that stuffed barrel first. A bit of heat & gentle persuasion.

If only small peices are broken out I just build them up with weld rather then try to weld in small pieces.

The clean up takes the time but if your careful & have enough tools to reach the hard to get places (files, sanding discs, grinding discs, die grinder etc) then it should hardly be noticeable, especially if you bead blast after clean up so the whole barrel has the same texture.

[Ji Gantor]

It was decided that instead of welding a replica piece into place it would be better to build up the wall of this crank cover with weld. This is TIG welding for those that don't know.

Ji

[Ji Gantor]

This crankcase was damaged by the drive chain.
It also was repaired by building weld up.

Ji

[holeshot buddy]

when heating aluminium
mark the area with a black texta
heat up until texta disapears
that is the right temp