Two motorcycles to build one

[Donovan1]

Hi, I bought a 2007 GPX 250 about a year back, it had been standing for a few years as the gentleman that owned it had passed away.The little ninja is in excellent condition with only 5000km on the odometer.
With the cost at only R2500, +-$160, I took the plunge.

I managed to get it going with the trusty help of a haynes manual and advice from this site. However it has proved impossible to change the title to my name, with neither the licencing department or the deceased son willing to help.(great frustration)
As I don't want to ride the motorcycle illegally and have the police pull me over.
I came up with a solution of purchasing a second motorcycle and building one motorcycle out of the two, as the second motorcycle I purchased has a clear title.

I purchased the second motorcycle for R5000, +-$320, it had been sitting on a farm for a few years. However the engine has damage- all the valve rocker arms had been broken as the cam chain had somehow jammed. The head had been removed by the previous owner as to inspect the damage.

My thinking is to remove the head from motorcycle 1 and place it on the crankcase from motorcycle no 2.

With never having opened a engine before and only having average mechanical ability, valve adjustment ect.
Are there any good threads on this website that detail a complete engine rebuild?
Is it viable to do this job myself or send it into a shop? Any advice would be appreciated.

[MrAtom]

It'd be much easier to just yank out the entire engine from one bike and put it into the other. In fact, when most people on this site break their engine, they just buy a new one and put it in.

[Racer x]

My advice is to first get the title in Your name.

Then strip bike two all the way down.
Save and the bolts and pieces and organize them.

Get bike one running. You can't ride it . But get it to rev and idle.

Then strip it down. The experience stripping the first bike will pay off. Clean and paint the frame from bike 2. Then build a new bike.

[VaFish]

Agree with the others, take the whole engine out of the running bike and put it in the non running one. Save the non running parts.

[MrAtom]

And maybe take apart the non running engine just for some fun exploratory surgery. See if maybe you can get it to start. And if you can, you can either sell it or use it for a different project or keep it as a spare.

[Racer x]

The only thing I can add is don't use a long screw to hold the fairing to the fuel tank.

[Donovan1]

Thank you for the advice. Unfortunately Im going to have to mat the engines together. Seems like such a waste though. The reason being is that in order to register the motorcycle here, the chassis and engine numbers need to match. If I swop out an engine, it needs to go for a police clearance. Not to be negative, but in South Africa, this is not a positive experience....Africa, I say no more!
Are there any definative threads on rebuilding an engine. There is a motorcycle salvage yard here called "Bike Hospital". They offer a service of compiling a working engine from parts of a scrapped motorcycle. Im not sure I trust this route though.
Another question, if I do go the route of rebuilding and matting the engines together. Should I split the cases before hand, to check if all is ok in the gearbox?

[spooph]

I'm not aware of a definitive engine rebuild thread, however, to swap the head over isn't that big of a deal as long as the cam chain is in good condition. If it is not, you will have to split the cases to lift the crank shaft out so you can replace the cam chain.

If you want to do it yourself, you can, we can help. Organization and photos of every step of the process will be required.

To replace the cam chain and swap the head over will require at minimum:

- base cylinder gasket
- head gasket
- paper gaskets for each side of the crank cases
- new cylinder bolts
- cam chain

Also, what a steal! that's like $250 for one bike, amazing!

My other thought is, if the cam chain is still in reasonable condition, why not just swap over the rockers from the good engine?

Either way, you will have to dismantle the broken engine completely to figure out what is wrong with it (also a really good practice so you don't mess up the working engine).

[RacinNinja]

To add to the above, I would not simply swap the heads and call it a day. I would split the cases regardless of cam chain condition to look for bits of metal that may have made their way into bearings, oil pump and other places.

[Racer x]

Definitely swap the case.
It is not as intrusive as you would think.
You will need the base gasket and head gasket and some others. But there is not much to it.

You don't need to change or unbolt the rods. Just pulley the bad engine apart for practice. The whole thing just need s to be dealt with in a clean environment. I am always worried about blown up engines. The bottom end is usually damaged.
Pull the covers , starter and everything off the old case.
Head off, cylinders off ,Pistons out. Mark and photo all.

The. Top case bolts bottom case bolts and split. Once the case is open photo it all and show it to us. Or grind away the cereal numbers and use epoxy to put in new ones. ( I did not say that)

[spooph]

Originally Posted by Racer x

Or grind away the cereal numbers and use epoxy to put in new ones. ( I did not say that)

realistically, this would be the fastest option.

Let's just walk through this scenario. You use the crank case from the blown engine to match serial numbers. What if something is wrong with the case, you'll have to replace it anyway? Now you have to use the other crank case with the wrong serial numbers anyway and you're back to square one, so yes, I think the first step should be what a few have said: Take apart the blown engine and inspect it all the way around to make sure you have usable parts and as a practice run so you're familiar with what's going on.

[Mohawk]

Assuming you have legal title to both bikes then where's the problem ? Swap the engine.
Declare the spare bike as spares. Not sure about tother countries, but in the Uk at least a frame & log book as in the title with number plate always stay together until the bike is scrapped. Then the plate goes back to the gov authority & the frame can NEVER be used again on a road legal machine.