Switching out engines

[BillyWinter]

Hi guys...

I don't know if this has been touched up on before, but I have looked and couldn't find anything:/

I've recently brought a Hyosung gt 125 and I was told, and have read in some places that you can switch out the 125 engine to a Suzuki SV650 engine? As the frame is practically the same?

I was just wondering if 1) Anyone could tell me if this is actually true or not? 2) How much it would cost to get this done?
Would be a massive thanks:)

P.s. Don't waste my time by posting about how it'l illegal and so on.... I am aware of the laws! I just want to know if it is possible, I'm probably not going to do it[/b]

[Kickstart]

Hi

Frame is nothing like the same. It is vaguely similar to the GS500 frame but even then I would be very surprised if the engine mounts are anything like the same.

All the best

Keith
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[BillyWinter]

I heard that the Hyosung GT group was bassed on the SV?
Because Hyosung is like the little sister company of Suzuki?
And the GT class is a budget bike so they all use the same frame and so on?

So if the frame is roughly the same a s GS500...? Taking into account that the mounting brackets aren't going to be exactly the same.... DO you think it's possible to swap out the engine with a GS500..?

[numpty2]

The other thing is the economics. A 125 in reasonable condition could be sold to pay for a bigger bike in good condition. 500cc bikes seem to be real bargains to me. I guess its because 600cc has become the new 500cc, so no-one wants those old CB500, GS500 etc. But these are good solid bikes. I'm just saying that you might be able to swap for a whole GS500, not just an engine.

And the other issue with buying a loose engine, how do you know it runs well? Whereas if it's still in a bike, it can be properly checked.

[Kickstart]

Hi

The SV650 engine is fairly similar to the GT650 engine, but not the same. However the frames are quite different (no idea though if the engine mounts on the SV and GT are the same or not).

Might be possible to swap the engine from a GS500 in if you were prepared to weld new mounts to the frame and swap much of the wiring loom. You would also need the exhausts, carbs, etc from the GS500 . Wouldn't surprise me if you needed the rev counter as well. Quite likely a fair few minor brackets would need to be moved as well (ie coil mounts).

As such while it might be possible the cost would likely make it financially non viable.

Suspect swapping in a GT250 engine would be quite easy though.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[BillyWinter]

Hmmm..... I did look into swapping it out to a GT 250 engine

Hard thing is finding the engine its self! Although I do know that teh GT 125 and GT 250 do have the same engine, and all Hyosung do is put a smaller piston in! So wacking on a 250cc bore kit would be fine as the bottom end is a 250!

SO you guys don't reckon it would be a not easy, but doable job?

and I woul just buy a bigger bike, problem is they've changed the law and I now have to me 19 to get my full license! So I'm stuck on a bloody CBT for 3 years

[numpty2]

Almost anything is possible to do, it just depends on your patience, skill & finances. Don't let any of us put you off trying, but be realistic. We all hear the stories of people swapping in bigger engines, but it is very rarely easy or cheap. Maybe in older, simpler machines it was more straightforward, but it's never just the engine you need.

And above all make sure that the donor engine is good. If someone is selling an engine on Ebay, why? It might be from a crashed machine, and be in tip-top condition. Or it might be about to blow up, with shot bearings, which is why they are selling it out of the bike so you can't hear it working. You might spend months of time & a small fortune, only to find that you've got nothing good to show for it.

Try and prepare a budget before you start. Assume the worst for all costings. Could you spend that money elsewhere with greater effect? But don't let us old gits put you off. If you do it, then tell everyone if it worked. If you fail it would also be useful for others to know. Just be humble though, or else the "I told you so" chorus could be unbearable.

There have been a few younger guys on the forum trying to do the engine swap thing, and it all got a bit unpleasant & abusive. Lets try and keep this all friendly. We'll respect your enthusiasm and drive, and you'll respect the fact that with age comes wisdom (in small doses admittedly).

[Kickstart]

[_Iain_]

GT650 is based around sv650, specificly engine wise it's an older sv engine making a bit more power.

Hyosung made suzuki's engines, that was about it as far as i remember.

Regarding the 125 engine swappage;

The only engine that will go straight swap is the GT250 engine. The frame is BASED around an old GS500 frame, but its significantly different & would require great amounts of fuckery to get a GS engine in.

How i'd do it? Assuming i wanted a 250 on L plates?

I'd sell the GT125. I'd rake round ebay and buy a minty GT250. I'd also purchase a GT125 frame with v5 from ebay. I'd then swap every nut, bolt & washer onto the GT125 frame & remove the 250 stickers from the plastics.

The 250 engine is EFI, the 125 is carbed. The 250 has bigger pistons, barrels, and a different crank. The 250 has USD forks, the 125 doesnt. The 250 has twin discs on the front, the 125 doesnt. Hence it's significant ballache to convert a 125 to a 250.

To do the conversion, the tank would probbably want changing, the wiring loom, the rear sprocket, all the bikes electrics to match the new loom etc. Not worth the hassle.

The GT125 frame & the GT250 frame are identical though, so it IS doable, and i've seen it done before. Plus, when you get your 33bhp licence, you can swap it all back onto the 250 frame (thus making it more valuable than the 125) which wont have been MOT'd all the time it was running on the 125 frame/book & as such in DVLA's eyes wont have clocked up any mileage over the year or so you've been riding it on a 125 frame. (subtle hint - change the clocks to a different set when you build it into the 125 frame.)

Then sell the 125 frame, with a v5 back on ebay for whatever you paid for it. Then sell the 250 for pretty much what you paid for it, as it'll be very low mileage for its year.

Full of win. I did a lot of research into this, then decided that i'd bosh myself through the tests quick sharp & have a lot more fun on a bike with double the power of the 250 when the restrictor washers magicly fell out on the way home. Which i did, then crashed it after a few weeks like a complete fucktard.

OR

Behave, do tests, dont get nicked, go to church blahdeblahdeblah.
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