Putting a different motor in a frame?

[glice]

How hard is it to get a motor in a frame that it wasnt made for? I'm guessing I would need to see an engineer? any idea of cost?

[hmurphy]

My friend and I had never ever done this sort of thing before and we managed ok. We had to learn to weld using an arc welder. As long as your frame is steel (makes it easier) all you need is some scrap steel and a welder (MIG or arc, MIG is much better). It all depends on what frame and motor really. The motor needs to fit in nicely so that you don't need to modify the frame a whole lot (just modify the engine mounts really), and the motor needs to be positioned so that the front and rear sprockets line up.

If you haven't done this before and you have the tools to have a go, give it a shot. But TAKE YOUR TIME!!! You don't want a badly mounted motor, things might fly off the bike... like the chain or the motor itself if you are that unlucky!

The only experience I have with this was mounting a TS125 motor into an RGV150 frame which was quite easy really, but was a LOT of work because I was very inexperienced with the tools required etc.

What motor and frame were you looking at anyway?

[Skunk]

For Buckets you just need to do a good job of it. There's not many engine/frame combos that are standard really (mostly FXR150's and they don't count anyway). Talk to you local Bucket guys and I'm sure someone will help you out.

I've done several now and with a welder and some thinking and planning it's quite easy. Cost me about $20-$50 in bolts, gas, etc.

[TerraRoot]

get your self one of these bars



and set it against the chain wheels, as long as the chain run is straight don't sweat the rest.

[LBD]

How hard is it to get a motor in a frame that it wasnt made for? I'm guessing I would need to see an engineer? any idea of cost?

Mate it all depends on what you are attempting and what vintage. ie a 748 in a kdx 200 frame may be a challenge.

so..
Is frame designed for HP and weight of motor?
Was frame designed to use engine as stressed member?
Can you position primary sprocket in line with rear sprocket?

The rest is just a basic ?...Will it fit?

[saxet]

As LBD says..Can you line up front and rear sprockets...Use the straight edge and take your time to be sure it,s lined up..don't forget to consider what might be in the way e.g. suspesion linkages etc.

[nudemetalz]

My advice is to MEASURE MEASURE MEASURE !!!!!!!!!!
See if the bloody effing motor will actually fit into the frame without modifying the frame so much that you ask yourself why did you bother in the first place.
A four-stroke single will not go into an RGV150 frame very easily........

[Buckets4Me]

I've seen several rgv50's with honda 100's in them
and even a lonchin 150

[Skunk]

A four-stroke single will not go into an RGV150 frame very easily........

I've seen several rgv50's... ...even a lonchin 150

You mean there's more than one nutcase out there? Who would've thunk it...

[LBD]

You mean there's more than one nutcase out there? Who would've thunk it...

Ungineers are by nature automatically included in the Nutcase contingent...and I know we are several on this site....

[YellowDog]

I would advise caution here. Actually getting the engine mounted is not the problem. It is how everything else hands together. If the engine is more powerful than the frame can handle, there are other tjhings to worry about. e.g. Brakes & dampers.

If you are swapping for a similar power output unit, then it shoildn't be a worry.

[Skunk]

I would advise caution here. Actually getting the engine mounted is not the problem. It is how everything else hands together. If the engine is more powerful than the frame can handle, there are other tjhings to worry about. e.g. Brakes & dampers.

If you are swapping for a similar power output unit, then it shoildn't be a worry.

Shouldn't be a problem... we're talking Buckets here - on a good day 15hp...

[YellowDog]

Fair comment. I don't think 15Hp will kill anyone.

[caseye]

Will if it hops outa the frame and lands on their ead!
Give it a go mate, like the others have said, measure and align things and it'll all go fine.
If this was a road bike then all bets are off unless you really do know what you are doing/ Frame design,engine weight,frame flex,engine rigid or rubber mounted, integral frame component or not, all these things then come into play.
have fun an get someone to check what you have done if you are not sure, can't hurt to have a sceond opinion.

[Yow Ling]

The best thing I think you could do, is tell us what frame and what engine u thinking about, many people have spent hundreds of hours of their employers time figuring out what fits and what doesnt. some fits are easy some not, almost anything can be done. FXR engine wont fit in a RG50 frame easily, most other things will, I know this because somebody tried. Most things have been tried. Some things will fit and be lame (AX100). People know just ask