Blowed 'er up real good

[scooter5002]

Hey Roosty, I think I took the bottom end out of my 93 CR250 yesterday. Started taking it apart last night but ran out of time. Have been considering a big bore cylinder from Eddie Sanders racing for a few years now, just wasn't going to spend the money until necessary. Apparently now it's necessary. Was thinking of the the 330 cc, but should I stroke it as well to more or less keep things somewhat square? Rode an Ohlins 360 kit years ago and loved it but stalled really easy. That was the only negative with it.
Was just on their site and I see they have a kit on sale for 400 bucks OFF! Glad I waited. It's for the 86-89 TRX longstroke motor though. How much work to make that thing fit? Or just jam it on sans spacer plate?

[100hp honda]

i dont believe the esr cylinder works on 93 cr250 cases. first problem i see is you have cooling ports in the cases.

[scooter5002]

Your losing me here, 100. Are you saying that you think it's for an air-cooled engine? The pics on the website suggest otherwise. Or just flatout different plumbing on the coolant? My buddy from Michigan says that this cylinder is the kit to get. He's pretty knowledgeable, so if this is an option, I'm pouncing on it.

[Gmbond]

I think what 100hp is saying unlike a cr500 cylinder where the coolant has an external hose, the 93 cr250 flows from the water pump up and into the cylinder thru holes in the cases and thru the base gasket.

Not a clue about the esr cylinder though, I've know nothing about that swap.

Love to hear how it works out though! Pics would be even better!

[100hp honda]

GMbond summed it up. your 250 has coolant port through the cases. the esr cylinder have the ports in the cylinder. i would investigate alittle more before pouncing

some of the older cr250 have external plumbing but they have a extra hole in the case for the power valve. not even sure how that would work

[scooter5002]

Well, I thought of that too, but I thought I'd seen the right side of the cylinder in a pic and no water port, so through the cases like my 93. If it's do-able, it's going to happen. Need more than 250 but less than 500. Just HAVE to have it. In my 93 chassis. OH ya!

[scooter5002]

nfm

[scooter5002]

GMbond summed it up. your 250 has coolant port through the cases. the esr cylinder have the ports in the cylinder. i would investigate alittle more before pouncing

some of the older cr250 have external plumbing but they have a extra hole in the case for the power valve. not even sure how that would work

fuck

[100hp honda]

look at the top of the case
http://www.ebay.com/itm/Crankcase-Crank ... 1c1fd31c22

look at the bottom of the cylinder http://www.ebay.com/itm/HONDA-TRX-250R- ... 3f098b4a62

[100hp honda]

and theres no telling if the studs are the same width. i think they are but still you got the coolant problem mentioned earlier

[scooter5002]

Fuckity fuck fuck fuck. There goes THAT wet dream! It's almost like I need to slap that on a 500 bottom end, if THAT'S even an option. And it's likely not, at least without 5 grand worth of machine work.

[100hp honda]

It's almost like I need to slap that on a 500 bottom end

let me know how that works out

[Gmbond]

Check out
http://www.madmanengineering.com/bigborekits.htm

They say cr250- 330cc or 295cc

Funny sometime how you want a little more on a certain bike, 93 was a good chassis always liked the looks too.

[scooter5002]

It's almost like I need to slap that on a 500 bottom end

let me know how that works out

So you're saying it can't be done? Well, maybe I need to "pounce" on it after all, send all my shit up to Roosty, and just tell him to call me with the amount of cash I owe him when the job is DONE! Oh, I smell smackdown here. Lol. The 5 has the longer stroke I wanted, by 6 mil I believe, an adapter plate/spacer an we in bi'nissss! If anyone can do it, it's Adam. (Isn't the 250 a 73 mil stroke and the 5 a 79? Goin by memory here.) I'm sure it isn't quite that simple, but I'm sure it's possible.

[scooter5002]

Thanks Mike, I'm not giving up on this. I LOVE that 93 chassis and look. Corners like it's on rails, but my 265 lbs says "I need more power". I won't be able to lose 60 lbs. Dogger315's 93 resto gave me a boner that took DAYS to go away. WOW, it is nice.

[Gmbond]

Im working on an odd one over the winter

2002 YZ125 chassis with a 1991 DT200 motor, electric powervalve, counterbalanced.... This motor is damn near electric it is so smooth and yet stone stock is rated at 31hp. This is the motor every one with a yamaha blaster quad wants as the air cooled blaster, without a powervalve puts out 17hp. The bottom ends are basically the same.

As for the old question - Why? Well why not?

[scooter5002]

Exactly. If you want it, can afford it, and it can be done? Do it. Life's too short. Enjoy yourself while your here.

[Gmbond]

Bingo!

I've got little money in this project and if I can sell off the yz motor parts I have left over and even some of the dt chassis parts I'll be into it for nearly nothing.

I'll be ordering a new piston for it and putting it together fresh, need to learn to tig steel lol ( kind of funny that I only learned to do aluminum... Lol)

Since the Dt200 was street legal I think it would be a fun mini motard set up too...

[100hp honda]

people do crazy shit everyday. you see the guy who put ktm cylinder on a suzuki ? might look into the madman link. the 350cc deal sounds cool

[other]

GMBond, I built one of those YZ/DT hybrids years ago, and it was the BOMB ! Mine was obviously older componentry, as I used a YZ125L chassis, that was not even a year old at the time the original engine 'grenaded, and a DT175MX engine overbored to 191cc. Although I built it in '84, it was so fuckin nice to ride (KDX muncher !) that I kept it right up till about 2000 or 2001. I still have magazine articles about it when it was first built (I called it a YT200, yeah OK I was a young wanker !)That "scrap yard special" won a state round enduro outright, and finished third in the SW centre enduro champs, ridden by an green 23 year old, it was that good (the bike, not the green rider !)
I always fancied building another up to date version of it. The only downside I guess with the DT200 engine is the electric solenoid activated power valve, which means retaining the battery etc . . . but WELL worth building ! The air-cooled version I did was a piece of piss to do, too . . . .

[hoofarted]

I just did some reading on the DT200 in a Blaster. I happen to have a Blaster that can use some extra power. Did a quick search and didn't see any DT200s for sale. Well that was fleabay and local CL anyhow...

[Gmbond]

I just did some reading on the DT200 in a Blaster. I happen to have a Blaster that can use some extra power. Did a quick search and didn't see any DT200s for sale. Well that was fleabay and local CL anyhow...

The DT200 was never sold new in the US, so canadian market would be your best best....

However, the Yamaha WR200 was sold in USA, and is almost identical in physical shape as the DT200 (center motor mount is narrower) but has some better things
- No battery needed for electric powervalve
- No oil injection to need to be removed
- Plated cylinder
- Bigger reed block
and a complete running wr200 can be had for fairly cheap i believe

[hoofarted]

I just did some reading on the DT200 in a Blaster. I happen to have a Blaster that can use some extra power. Did a quick search and didn't see any DT200s for sale. Well that was fleabay and local CL anyhow...

The DT200 was never sold new in the US, so canadian market would be your best best....

However, the Yamaha WR200 was sold in USA, and is almost identical in physical shape as the DT200 (center motor mount is narrower) but has some better things
- No battery needed for electric powervalve
- No oil injection to need to be removed
- Plated cylinder
- Bigger reed block
and a complete running wr200 can be had for fairly cheap i believe

I found one in LA for $1100. Cool - thanks!