Ninja 250 motor transplant... what motor to use?

[B440]

well, the cr250 coil can be converted easy and a dc regulator added, I do it on the banshee's. use a ignitech programmable ignition, super simple starts with spark on every kick... I did the same on my cr500 power streetbike.... it did start a whole lot easier.... ever try to start a cr500 engine stock?? my god!

use led lights to save power.... I never had an issues with low batteries....

ex500 engine....kinda boring....I think... Ill checkout the trx250 motor, forgot about that one! I was picturing it in my mind as I had checked it out before but could not rememeber the name.........Thanks for reminding me!!! I am pretty sure they are tons around, tons of parts as well....going to see if they make as much hp as the cr250....

Yes. As much power, easier to get higher wattage for lighting, counterbalanced, 6-speed. Tons of upgrades; 310 powervalve, etc. This is the way I'd go. The only thing missing would be oil-injection like the RZ350's had. I'd like to have the trx engine in an 08+ ninja frame.

The CR250 and CR500 just don't have enough room under the left-side cover for proper lighting.

I've had two CR500's, an 89, and a 97. Easy to start when tuned properly. Cold starting required "the method" but once they were warm, I could kick-n-go like a 250 as long as I wasn't lazy about it

[B440]

well, the cr250 coil can be converted easy and a dc regulator added, I do it on the banshee's. use a ignitech programmable ignition, super simple starts with spark on every kick... I did the same on my cr500 power streetbike.... it did start a whole lot easier.... ever try to start a cr500 engine stock?? my god!

use led lights to save power.... I never had an issues with low batteries....

ex500 engine....kinda boring....I think... Ill checkout the trx250 motor, forgot about that one! I was picturing it in my mind as I had checked it out before but could not rememeber the name.........Thanks for reminding me!!! I am pretty sure they are tons around, tons of parts as well....going to see if they make as much hp as the cr250....

Yes. As much power, easier to get higher wattage for lighting, counterbalanced, 6-speed. Tons of upgrades; 310 powervalve, etc. This is the way I'd go. The only thing missing would be oil-injection like the RZ350's had. I'd like to have the trx engine in an 08+ ninja frame, or a CBR250 frame.

The CR250 and CR500 just don't have enough room under the left-side cover for proper lighting.

I've had two CR500's, an 89, and a 97. Easy to start when tuned properly. Cold starting required "the method" but once they were warm, I could kick-n-go like a 250 as long as I wasn't lazy about it

[DynoTune]

im short....after trying to kick my cr500 engine tons of times, I gave up.... new 12vdc ignition... started so much quicker

[B440]

The two bikes I owned did have the factory scallops over the exhaust, which made it easier. The older bikes and any bike bored out to max would be a lot harder to kick with full compression. I had a decompression valve installed on the 97. I could start it on the side of a muddy hill with the kicker facing the hill. Best mod ever

Some ignitions were better than others. Mine never gave me issues. I hated the stock carb. Switched to a PWK and it finally idled longer than 30 seconds and started easier when cold.

[DynoTune]

well, i put the cr250 motor in place..everything looks good to go. Fabed the motor mounts up. I should have it bolted in tommorrow if all goes well..Dam, this bike is going to be light! Ill post up some pics

[DynoTune]

working on the pipe now...I keep pulling parts off..getting lighter and lighter.. to funny...

[B440]

Exactly how much of a kit will you be making? Just the motor mounts, or the longer radiator hoses, and a pipe?

[loki32687]

I kinda want to ride that.

[csmutty]

I really want to ride that.

[stoinkythepig]

There's a big piece of structure missing between the steering head and the swingarm pivot.


I don't think this frame was meant to work without the engine, or some other structure, tying the bottom of the steering head to the swingarm pivot. Without that, the stress on the remaining frame is excessive. I think you need a pair of tubes under the engine.

[DynoTune]

Yup, there will be a cradle under the engine going up to the top. For testing, this will be just fine This is the basic test bike... mostly dyno time not alot of street riding. Once we feel this works well, we will buy a 2010 modern 250.... new body style....
We will fine fit what we have learned on this bike to the new bike as the motor is the same.
Im not sure about a kit....I know we will make the whole thing a bolt on deal.... We might just buy the bikes at auction and do the conversions in house.
The kit would include
Custom Pipe
motor mounts
custom kick start lever
Programmable ignition with 12vdc battery
12VDC coil/regulator
shift linkage adaptor

lets see how this one works first Working on the pipe today. Ive made some 2 stroke pipes before....not fun... I need a company to make me them so it will be a while before we can get that moving...

[DynoTune]

Got the pipe mocked up...its going to fit perfect... does not hit the body at all. It does sit just a tad low but thats because the pipe is massive...nice little 2 stroke bulge.... I should have the pipe welded up early next week... I need to document the pipe first so i can make more just in case ill post up some pics once mounted... looking sweet!

[maxim_X]

How do you make sure the pipe designed is right? Is there some sort of formula for the design?

[DynoTune]

well, in the past ive designed using two stroke software that prints out paper as a templet. Since im just doing R&D I simply use a stock pipe, cut it up and rotate the sections to make it work. Keeping in mind to not change the length. This will tell me if I have enough room under the bike for the pipe needed...and its looking perfect!

[DynoTune]

Got the pipe all done, motor mounted... finishing up the coolant hoses. chain, throttle etc... its fitting all real nice! Lets hope the vibration is to not excessive. Top speed looks to be about 90mph.... but it should get there quick! The bike weight right now is 275lb and with 45hp....should go just fine
stay tuned!

[CBR929RE]

needs a new case cover.

[Rada]

Nice...

Now build one with a Rotax 670 twin 2T....

[Stromper]

Banshee

[Garrett]

I didnt think the quadzilla was counterbalanced.....Thats why i opeted for the cr250... I put a cr500 in a streetbike... I did the best build ever for this attempt... just to much vibration, even with custom fully isolated rubber mounts.... the body cracked, mirrors rattler bad...dont get me wrong, I could have continued to work on it but it just sucked to much.
Attachment 36995
Attachment 36996

then converted to a 115hp banshee motor
Attachment 36994
banshee was the way to go.... smooth and fast!

The rd motors are to low tech... plus they have 2 cyls/ pipes... trying to make it light.
The cr250 has 48 HP....the stock 250 ninja had 24hp.... I have a cr250 motor now... im leaning this way heavy as I can get cr250 motors everwhere cheap. The quadzillia motor is very hard to find.

Someone probably answered tihs already. But all of Suzuki's 2 stroke race quads were counterbalanced.

OP, go a GT750 or H1 motor

[B440]

I bet Garret could hook you up with lots of cheap Suzuki LT250R quadracer engines. Plenty of those around, counterbalanced, lighting coil, etc.

[Garrett]

Hahaha! I got out of the Quadracer game a couple weeks ago. No more 4 wheeled off-road machines for me. They're all way to beat to be worth flipping.

[DynoTune]

the cr250 engine is so main stream with all the shift cart racers....tons of parts.
An h1 or h2...my god...3 f-in pipes under that bike... it barley fits one big CR pipe LOL.

[Stromper]

http://www.ebay.com/itm/Yamaha-Bansh...2b6866&vxp=mtr

[B440]

The Banshee motor has been done before.... by Yamaha. The RZ350

[JohnnyV]

Got the pipe all done, motor mounted... finishing up the coolant hoses. chain, throttle etc... its fitting all real nice! Lets hope the vibration is to not excessive. Top speed looks to be about 90mph.... but it should get there quick! The bike weight right now is 275lb and with 45hp....should go just fine
stay tuned!

Is ground clearance on right-hand turns going to be an issue? From the pic it looks like it might