As above. Been ripped off on a private sale and bike gave up on my first trial. Great introduction to my new hobby. The questions are, how difficult a job is it to swap crank cases. I am a semi skilled engineer by trade but know little of engine internals. I realise I will need pullers but have also heard something about having to freeze and heat casings?

Any links or help mucbh appreciated.

Thanks

uh o

thats a big job! basicaly, everything needs to come out and be put back in the new cases .

look at jim snells Gas Gas engine repair videos on youtube.

yes you sometimes need to heat up the cases to get bearings out etc etc

when installing the bearings back in the new cases put the bearing in a freezer/fridge and heat up the area its going in to.

it makes it alot easier trying to get it back in.

good luck,

ben

oh and the cases...

alot of moeny.

pt 1.http://www.youtube.com/watch?v=XgKLrVBn2O8

pt 2.http://www.youtube.com/watch?v=pQ7OmoyATgU

pt 3.http://www.youtube.com/watch?v=pQ7OmoyATgU

Have a look at these, you will see that the Pro motor is nice to work on. With a little of your engineering skills it should be fairly straightforward.

Tjänare..

This is some job, but not too difficult. The videos are very helpful.

Before you begin you will need to get at least a flywheel puller, paper gasket for case halves and a new base gasket for cylinder. Personally I would have got new seals and O-rings for the crank bearings too.

The puller is a M27 Dia x 1mm Pitch, right hand male thread. Unfortunately they dont have this at Biltema :-( Where in Sweden do You live? Maybe I know someone nearby that you can borrow from.

Tools needed are - besides the flywheel puller - standard stuff. A hot air gun is useful for expanding cases befor mounting bearings, but hot water or even baking oven can be used.

Good luck, and dont hesitate to ask if your stuck at something.. :-)

-Jan

Where in Sweden do You live?

I live in the UK. It's an odd nick name I know. Many thanks for the help guys. I'll probably be back in touch when the cases turn up. Videos are very helpful.

Many thanks

I live in the UK. It's an odd nick name I know.

haha.. Fooled me easy there::

I don't think its very common to crack the crank cases. Are you 100% sure its the crank cases that are cracked and not a more external part of the casings ?

Edited December 28, 201213 yr by blocky

before going much further you need to get someone in the know to have a look at these cases. unless they are broken through a machined face you can do a hell of a lot of repairs using moly metal. where about in the country are you?

Hi Swede

+1 on Paul W's advice (again)

unless they are smashed, a very good fabricator can fix many issues. The job is a specialist one but a hell of a lot easier and cheaper than the alternative you are contemplating. You may need to carefully skim / make good some mating faces but unless it has mashed somewhere unfortunate (across a major bearing housing etc) you may be lucky. There are many tricks to avoid the distortion experienced during welding, but you cant roll back after the distortion has occured.

Dont go looking for your average MIG welding fabricator, you need a specialist TIG aluminium/stainless fabricator. Ask to see some examples of his/her work.You can help make the job easier for the fabricator by cleaning / degreasing everything and perfectly masking areas you dont want to dissasemble (lots).

As someone else said, come back and ask again if you are unsure. Some photos of the damage will help determine whats possible. Also people tend to know their local fabrication experts so you might want to tell us where you live so that some names can be suggested. Good fabricators are magicians!!

Dom

Hi Swede

+1 on Paul W's advice (again)

unless they are smashed, a very good fabricator can fix many issues. The job is a specialist one but a hell of a lot easier and cheaper than the alternative you are contemplating. You may need to carefully skim / make good some mating faces but unless it has mashed somewhere unfortunate (across a major bearing housing etc) you may be lucky. There are many tricks to avoid the distortion experienced during welding, but you cant roll back after the distortion has occured.

Dont go looking for your average MIG welding fabricator, you need a specialist TIG aluminium/stainless fabricator. Ask to see some examples of his/her work.You can help make the job easier for the fabricator by cleaning / degreasing everything and perfectly masking areas you dont want to dissasemble (lots).

As someone else said, come back and ask again if you are unsure. Some photos of the damage will help determine whats possible. Also people tend to know their local fabrication experts so you might want to tell us where you live so that some names can be suggested. Good fabricators are magicians!!

Dom

Bear in mind the cases are Magnesium, not Aluminum, in the Raga.

Jon

Bear in mind the cases are Magnesium, not Aluminum, in the Raga.

Jon

Add to that, the standard ali cases prolly cost less and work fine, just a thought. Magnesium can be welded though, if you find the specialist welder, depends upon what exactly you are dealing with here, as if re-machineing is required, it may get too expensive to repair.

repairing it is an option. but you're on the right track by renewing.

its the only way you will ever have piece of mind and faith in the bike.

Having worked on plenty of these motors i would say go for it, they are an absolute joy to work on. Very straight forward, simple design that needs no special tools except the flywheel puller.

To pull the motor take the clutch side cover off and cable tie it to the bars (no need to disconnect the clutch hose). Take the flywheel off and remove the stator and cable tie that to the left side of the handlebars (no need to remove wiring). Remove the tank, airbox, and carby, then pull the motor. It's pretty obvious and straight forward.

Once you have the motor on the bench and start to dissassemble just be careful to take note of all the shim washers and thier placement. The left side case will come away from the right side case with the gentle use of a soft rubber mallet. All the gear cluster and crank will stay in the right side case.

To remove the bearings from the cases pop the case in the oven on a low heat (120 - 150 degrees) for 15 minutes and they will just knock out with no force at all.

A good tool is a can of plumbers Pipe Freeze. It is an aerosol can of basically pure freon, and works great for quickly shrinking parts (or chuck them in the freezer for an hour or so).

Just always think about using either heat or cold to remove parts. There is no need to force anything on a Gas Gas motor.

PM me if you need any specific advice and i'll walk you through it.

Regards

What sort of a--ehole sells a bike in that condition,cant believe they didn't know.I would bite the financial bullet and replace the casings with the standard Pro casings rather than the RAGA magnesium ones.Magnesium can be difficult to weld successfully,you'd have to strip the engine anyway to do it.Worth replacing the main bearings and seals while its apart.They are terrific bikes,you'll love it when its done