Shoving A 500cc Engine Into A Honda Nsr

[submaniac]

Found this website, and found it incredibly interesting. I *think* it can be done with the Thai 150cc bikes. But I don't know for sure...anyone want to be the guinea pig?

http://www.dreamgate.ne.jp/NSR/Project%20N...0/500_main.html

[ozzydom]

Found this website, and found it incredibly interesting. I *think* it can be done with the Thai 150cc bikes. But I don't know for sure...anyone want to be the guinea pig?

http://www.dreamgate.ne.jp/NSR/Project%20N...0/500_main.html

First problem is that the NSR 250 is an entirely different kettle of fish to a Thai spec NSR150, I think it may be an exercise in futility as the end result would be way under specced in the essential component area like brakes, wheels etc etc.

[Phil Conners]

Did you ever get as far as the conclusion?

Some quotes from Chris "I got it out for a good ride today and it just does not seem very rideable. It vibrates extremely, extremely bad, and it just did not feel right in the turns. Even when going straight, it will not hold a steady speed, it wants to jerk and kick. It just does not run like it is supposed to be in there. The vibration is just unreal. It feels like I am holding the dang engine in my arms when it is running. Then all of that mass in the crank spinning must be affecting the handling, because it did not feel like it wanted to lean as easily. I think mostly the vibration is scaring me more than anything. I just hate to ride it very fast when it feels like every bolt in it will vibrate out in less than 2 minutes."

So there you go, would Chris recommend this conversion? No!! Sure it can get the front wheel up in third gear, even fourth, but the bike is unrideable. Future plans for this NSR will see Chris rebuild his stock MC21 engine and go with that.

[submaniac]

Vibrations? Unrideable? Look man, I am used to riding Harleys!

[Thanh-BKK]

That's NOTHING.

I have seen a Zuendapp CS 25 (which is 50cc 25 km/h!) outfitted with a Yamaha RD 250 engine.... and a Vespa scooter with a Suzuki 4-Zylinder 750cc engine. Of the latter there was even a YouTube video around.

Best regards....

Thanh

[apetley]

That's NOTHING.

I have seen a Zuendapp CS 25 (which is 50cc 25 km/h!) outfitted with a Yamaha RD 250 engine.... and a Vespa scooter with a Suzuki 4-Zylinder 750cc engine. Of the latter there was even a YouTube video around.

Best regards....

Thanh

Hilarious

[deckx]

Found this website, and found it incredibly interesting. I *think* it can be done with the Thai 150cc bikes. But I don't know for sure...anyone want to be the guinea pig?

http://www.dreamgate.ne.jp/NSR/Project%20N...0/500_main.html

When read it i was thinking why would anyone want to replace a 250 twin with a single cylinder lump. As it turned out it was a crap idea..

An interesting project would be to put a 250cc twin into a NSR 125 or CBR 150..but i don't particulary like messing with spanners unless i have to..

[submaniac]

An interesting project would be to put a 250cc twin into a NSR 125 or CBR 150..but i don't particulary like messing with spanners unless i have to..

Actually I was sort of thinking the same thing as you. I would much rather have a twin than a thumper.

When I found the article I was searching to see if anyone has ever done a 250cc engine swap. I have a Yamaha TZM 150 (not an NSR) and I was curious if anyone has ever swapped in an engine from a Yamaha YZ250 (dirtbike) into the 150cc chassis. I *think* the TZM has a bored out version of the YZ125 engine (both YZ and TZM are 2 stroke thumpers, watercooled, ypvs system, etc.), and the 250cc engine swaps into the YZ125 engine bay, so I was thinking it probably would fit in. And the YZ250 thumper makes 55 hp.

I couldn't even find anything on the TZM so I tried searching on the NSR to see if anyone has done something similar with a 250cc CR (dirtbike) engine. And then I found this. I still think it is cool though (something about being able to do a wheelie in 3rd or 4th gear). I probably would stick to the 250 on the swap, as I think it would be a more direct fit.