Hi all has anyone fitted the ktm 660 supermoto engine into a 640 and if so what did they need to make the change .I know i will lose the electric start but thinking it maybe worth the extra power

cheers

Dave

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Hi,

Nice bike, but why do you want more power?

More power = less reliability and the parts for the 660 engines will be harder to get and probably more expensive. The parts for the racing 660's are incredibly expensive.

I got my standard 640 engine rebuilt and balanced by Swampy when it was new so it was as smooth, economical and as powerful - with the standard carb - as possible.

__________________
Jerome

fowb.co.uk

That electric starter may just save your butt someday. It'll come in handy, if you have to have both feet firmly planted on the ground.

daryl

This is an exercise in wasted time.

You won't gain enough power to make the expense and hassle worthwhile,
and you will lose reliability.

There is no need for more power except when on paved roads, because the power the stock bike has is sufficient for any off road conditions.

Bottom line : if you want more power, you should buy a 950 Super Enduro. But unless you have superhuman strength and world-class riding ability you can forget about doing any serious off road with that bike.

Thanks for the replies it was just a thought just encase i was going to do a engine change in the future ..

thanks

Dave

Hi you can quite easily change your 640 which is really a 620 to a true 660cc with a crank and barrel and that way keep your electric start, the 660 bore and stroke equates to a smoother engine as well so less vibes and a lot more torque, the problem with the 660 SMR engine is the high compression that could cause problems with crap fuel in remote areas and the first two gearbox ratio's are higher than the std LC4 engine so you dont have the std crawler 1st gear to get you out of trouble in tight going.
I know this because i have a 660 factory motard that i raided the engine out of to put in an old 620 frame i could register with an adventure tank for a trip i decided to do at the last minute and the original 620 engine rebuild was'nt near ready.
Basically what you get with the 660 is more power but usfully more torque a load more torque.
Your other option is to install a 660 cam with the matching valve spring kit with an FCR carb this will give you additional ponies with good reliability at a more affordable price.
Hope this helps i know this post maybe old, ive just joined after seeing your post but couldn't help commenting, your on the right track the 660 is not a big bore kit for the LC4 motor the older LC4 rally bikes run a 690 or 710 kit that is still reliable it just comes down to cost as always, one point i found getting on and off your bike just to kick start it everytime because you stop to take in the view a pee a quick chat "where the hell are we" etc soon becomes a pain when your bike weighs a ton, stick with the button at least that weight is down low. cheers
Deeds

Yeh thanks for that some interesting stuff
I do like the idea of 660 top end with barrel
Pistons and camshaft with the fcr carb

I will keep an eye open for any of that stuff on
eBay . Thanks for your help

Cheers

Dave