which CR250 motor?

[Mik329]

Dont remember what motor was best for some low end and decent power. 95-97 maybe?

[Rhino89523]

Best low end power comes from the CR motor with double the displacement. couldn't resist.

[plynn41]

2001 is considered by many to be the best 250 motor Honda ever made, and that's partly because of the good bottom end. The '97-98 model is NOT a low end motor. It has one of the more vicious mid range hits and also screams on top. I just sold one recently and can vouch for this.

[Roostius_Maximus]

2002+
by far the best 250 honda made, some guys will talk up the 2000-2001, but the real 250 is the 2002 design, the cylinder starting in 2005 i think, maybee it was 2006.
2004+ has a tps on the carb, 2003 has a heavier flywheel.

I've been wandering arround the 250 motors a bit lately.
Kart application these are getting an honest 63hp at the crank and 30ftlbs, but completely out of the mx useable rpm range or delivery

I've got a good porting design for all the 1997-2007 250s

[Tharrell]

I've got a 2001 and love it, best bike I've ever ridden (prolly change after I do a 500AF).
I did a lot of research on it to see what the best one was.
No offense to roosty but, virtually everybody including Eric Gorr thinks the 2000-2001 was the best Honda ever made.
Matter of fact, Gorr thinks it was the best 2 stroke ever.
Problems with the electronic power valve and case reed induction was what I heard.
I personally think they were on the right track but dropped development in favor of the 4 strokes.
Even though they had been playing with E valves and case reeds since the early works bikes, they screwed up by changing too much at once without adequate testing on the production models. (imho)
I haven't ridden all of them so I can't really give seat of the pants advice on each and every model.
I can tell you that mine rocks, nothing but a pipe and V force reeds.

[dannygraves]

the '02+ are a technological marvel and really pushed the engineering factor to the point that every year saw huge changes. I had an '03 and many parts (like the reed block) were different from '02 and '04. the '01 was an excellent motor for good rip but a '02+ would see better track times everytime.

[100hp honda]

didnt have no trouble selling my '04 engine . some kart dude snatched it

[plynn41]

Y'all keep forgetting the poster wanted a CR250 engine with good low end. I'm not dissing the '02+ motors, but they are not known for low end.

[Roostius_Maximus]

I'll completely dissagree, if torqe and 250 are mentioned together we're either talking the 02+ honda cr250 or the ktm

the 02+ is thee engine when looking for tq, we ran a 2000 bike also, It has nothing on the gen 3 engine.

The exhaust port was made smaller in 2004 to help with the traction, the tq numbers came up 1 or 2 but the hp remained the same. I stil have my 02 and bro his 04.
THe kart guys eliminate all the exhaust valve, port the 04+ motors exhaust to replicate the 02, run the 02-03 ignitions on them, the vf3 and a strait inlet, tough to compare to mx prep.
I'm willing to take the 2 in my stable to the dyno, and borrow an 01 from a friend that stil races it. could be later this fall tho.
the early gen 3 motors used a flat top piston, later (05 if i remember right) went back to a domed piston, they also had a 2 piece cylinder making the exhaust face and bridge stronger by bolting the valve access area to the exterior instead of having to fish the valves in thru the bore side.
With the adjustability of the exhaust valve you can make the motor suck thats forsure, but with very little adjustment from stock it can be a real ripper.
The gen3 motor deffinately does not pull the rpm of the 00-01s wfo down the road, but it is consistantly faster in drags.

[Tharrell]

You'd think the E valve and case reed combo would have been pretty straight forward but, that's why all the different changes from one model to the next. They just didn't get it right.
If they had done one or the other and perfected it then moved to the other it probably would have been worked out to the good.
Hey, they had fuel injection on Marty Smiths bikes back in the 70's.
They've been pushing everything until that damn 4 stroke yammie won a national.
That's all Honda needed to jump ship on 2 strokes.
I know this might be a sore point but SH uses the 2001 engine in their 250's and the 4 wheeler they build.
I'm not an engineer or tech guy but, the 00 and 01 engine is the one in demand and I got one!

[Roostius_Maximus]

some kart info, http://ekartingnews.com/viewtopic.php?t ... c&start=30

[Roostius_Maximus]

a link to some pics and docs, 85 items left to load so give it a minute. These arent mine, stolen from the net when i started looking at 250s. I have both versions of the engines in pieces btw

https://skydrive.live.com/browse.aspx/. ... =documents

[Roostius_Maximus]

everyone loves the 00-01 engine, but theyre completely different and no one ever knows that.

[Roostius_Maximus]

its the 05-07 cylinder that was the strongest made part and the best port design, you'd think they'd have a dammn good handle on the engine by then, same platform for 5 years, same port dimensions for 3 of those, longest honda ever did something the same in the 250.
They also started using a new crank with bolt on stuffers instead of the cans that they had so much trouble with.

BTW, never use a Wiseco aftermarket crank in anything bigger than an 80, heck dont use them at all.

[dogger315]

Dont remember what motor was best for some low end and decent power. 95-97 maybe?

Speaking from my personal experience, the 2000-01 HPP port engines
were the best CR engines.

I raced in the 250 A class from 92 to 96 then the vet A class from 97 to
03 all on Hondas. My motors were built by Tom Morgan Racing and the
00 and 01 were the stoutest with a nice useable powerband. The 02 and
03 engines required a bunch more work (and money) to make the same
power and we were never able to achieve the same broad powerband.
The case reed design mostly yeilded a big midrange hit without much
below and above - ideal for Supercross, but not so good for outdoors. I
actually swapped a spare HPP valve engine into my 03 and immediately
cut a couple of seconds off of my lap times. The RC valved engines
suffered from design flaws like excess crank well volume, "boat anchor"
crank shafts, poor port timing, recalcitrant power valve actuators, etc.
Some of these problems were corrected, some weren't.

By 2001, Honda had developed and refined the HPP valve engine for
eleven years - which is why many believe the 01 is the ultimate version
of the HPP.

As was stated earlier, Honda pretty much stoped most R&D on the RC
valve engines in 03 when they put all their eggs in the 4T basket, so the
potential (if any) of this configuration was never fully developed.

Some anecdotal evidence for the superiority of the HPP valve engine is
their as well. Mike Larocco used a HPP valve engine in his CR long after
01 (much to Honda's chagrin) and like Tharrell said, the HPP valve engine
is the choice of Service Honda for their 250 hybrid.

If I were to rank the engines year to year based on my experience and
results, here is what it would look like best to worst:

2000-01
1995-96
1992-94
2002-03

dogger

[plynn41]

I'm willing to take the 2 in my stable to the dyno, and borrow an 01 from a friend that stil races it. could be later this fall tho.

That would be a fun comparison and I'd like to see it if and when!

I'll step out of the argument now because I don't have any personal experience with the case reed engines--only what I've heard and read. But Roosty, you're the first person I've heard that would recommend the later 250 engines to someone looking for "good bottom end" power.

Now if we were karting, well then,....

[Tharrell]

A couple of things......

I just know what I've read and what I have in the stable, like I said it's the only one I've ridden except for the 96 model.
Roosty may have some tricks we don't know about which would skew everything.
Dogger, when you gonna show the hoons your new bike?

I know, highjacked

[dogger315]

when you gonna show the hoons your new bike?

It's not quite done yet, but here it is so far. I'll post some more
pictures under a new thread as soon as I get it wrapped up - I
don't want to be complicit in your thread hijack

dogger

[seanmx57]

maybe Laracco didn't care about the Dyno

My 2000 motor has decent low end for St riding, for MX I could use more. 500's spoiled me.
when she is on the pipe better hang one good though.

Mine ran good (stock jug/head) with the stock carb, Vf3 and a SST/shorty pipe and silencer. Then I Put a pwk taperbored from 38 to 41+mm with an intelajet on it. Might account for some low end loss. It runs good on the pipe with that big carb. I almost looped it in sand MX whoops last year in 4'th gear. She stood straight up like a 500 will when they get traction unexpectedly.

Sure gen 3 motor CAN be fast, they just need a grand of work or at least a good carb to start with.

[Mik329]

I called Eric Gorr and asked him which motor he liked best for his 300 kit and porting and he said the 2001.

[Gmbond]

I've got an 06 Cr250 and while the motor is bone stock, I've added a flywheel weight, v force 3, jd jetting kit, fmf q silencer on the stock pipe. This is my woods/enduro race bike and I love it. It's smooth on greasy rocks and logs, and with a little clutching it leaps out of corners, I'm a "momentum" style rider and it works real nice for me.
My previous bike to this one was a woods setup 2001 Cr250 and while I never did "back to back" of the two I felt the 06 was better in almost every way. I still have the occasional cold wet fouled spark plug that is annoying but I happy. Still may play with a pwk air Stryker from a yz250 I picked up (has the TPS)

[bearorso]

Gmbond,

That will be the best thing you've ever done to the engine. Hoiking the Mikuni (though some of the E PV engine had Keihins, I think) is the go.

I'd use the E PV, case reed engine. Simple as that.

A big 'problem' - as well as that bloody Mikuni - was the smoothness of that engine - people thought, "no almighty hit, must be a slug" . Far from it.

I gather that the E motor (?) for the PV is hard / outragiously expensive to get, if it carks it.

A great engine, that suffered from lack of interest from Honda, they were busy going 'all 4 stroke, all the time'. What Honda have locked up in their engineering dept. with regards to 2ts would undoubtibly make most mfrs envious. And 2t riders cry in their beer.

A hell of a reason to despise Honda.

That SH uses the 00/01 engine is no influence to me - them saying it's the best ranks up there with the BS they sprouted about the 250R /X chassis being the best. The engine is probably the cheaper option / or the available (parts) option, but it also has a better rep, through the lack of understanding of the E PV engine. What they do is purely the best from their economic standpoint. Use the 250s (and when they bring down their stock of the < 010 Rs, go to the 'now better' 010 chassis for the MX version), Sell the engine (or use it in the Juniors they make, which gives them 150 engines to sell), for very good money, or, break it down for even better money, and use the roller for expensive specials. Great business sense, basically. A very good money earner - the whole chain of sales.

[2strokeforever]

i have yet to ride a 02+cr250 with low end snap or responsiveness, all the torque in the world is useless if it takes too long to get it

but i did notice they climb better than the yzs in a big gravel pit

rode 5 or 6 of them, a few were jetted good too

if i could get snap out of a 02+ cr250 id prefer it over the yz

[bearorso]

Just means you've yet to ride a good one

Each person has their 'druthers.

I'd go for the latest, healthiest engine I could find. I've ridden some great case reed CR250s - pissing off the Mikuni is a big step to being able to make it do what you want.

Then, 'have at it'. There's the beauty of 2ts, even the most 'modern' one, the last of the CR250s (and isn't that a sad thing? Anyone that thinks KTM 2ts are 'developed', are kidding themselves, not when you can fit 380 components, like crank and barrel, to an 011 /012 250 /300 engine), you can do a hell of a lot to them, without spending mega bucks, if you know what your doing.

I think , on ' twostrokemotocross.com' there may still be a selection of articles done under something like "building a modern day CR250" that goes into a lot of detail with regards to the E PV engined bike.

I'm not interested in arguing about what engine's 'better', I'm just saying that I'd personally use the latest version of the Honda 250 - I've ridden a few that were the ducks guts.

[Gmbond]

What is love about my 06 is how smooth it is, even with the mikuni on it. And where some may feel it isn't fast, it just hooks up and pulls, and I've pissed off many 450 riders in different situations, all in all I'm happy. I'll eventually play with the keihin and see what that does.

The gen3 chassis is awesome too in my opinion! Was an easy transition from gen2 to 3, although it does like to be ridden a bit more aggressive than the 2001 did.