cr250 motors

[Project300EX]

I've got a few questions about the different cr250 motors. First of all what are the more powerfull years? I'm looking at one for ubber cheap. The guy said it ran good, but was having electrical problems. After taking it out the piston seized after time. I can get it for $110. What kind of power could I get after a topend rebuild? He isn't sure what year it is, but believes it is the '81-'83 model. How are they power wise? Here's a pic of the motor and yes I know it looks rough. Thanks.

http://i6.ebayimg.com/02/i/08/e5/4f/1d_1_b.JPG

[Project300EX]

Also please don't turn this into an argument thread. I've read them all and don't want to hear any of it.

[rooster300ex]

The counter sprocket is too. The atc air cooled engines of that year were too.

I'm sure you will get plenty of power out of it, but being so old of an engine I would rebuild the whole engine. Seals & everything.

[4TraxRider]

I would guess that motor would be putting down HP in the mid to lower 30's. The old CR engines were great. If you could ever find an 86' they IMO had one of the best powerbands of any of the old CR's, and i've had a lot of them.

[Project300EX]

I'm glad you guys noticed it being on a different side. It would be a pain converting the sprocket to the right side of the axle.

[2muchquad]

I'm glad you guys noticed it being on a different side. It would be a pain converting the sprocket to the right side of the axle

Not really,just get a swinger setup from the 82 to 84 atc 250r 3 wheelers.Or a rearend from a cannondale would be trick.Those were some strong motors,easily 36hp plus.

[rooster300ex]

Originally posted by 2muchquad
Not really,just get a swinger setup from the 82 to 84 atc 250r 3 wheelers.Or a rearend from a cannondale would be trick.Those were some strong motors,easily 36hp plus.

Ol honda knew how to put down the power back in the day too.

[Project300EX]

I forgot the early atcs had the right side sprocket. I'm just afraid if I get it it will be hard to get all the parts. Also what would be the best harness to use?

Here's the parts I've been looking at for it. Anything else you would suggest or that I missed and what kind of power would it put down? I've tore down and rebuilt some 4-strokes, but don't have any experience with 2-strokes. I will probably use an old rough FMF pipe and fabricate it to fit with whatever FMF silencer I can find on Ebay.

.75mm overbore Wiseco piston kit $90
Athena complete gasket set $30
Vesrah connecting rod kit $80
Wiseco pin bearing $10
FMF fatty gold series pipe $75
FMF power core silencer $100
Keihin 36mm carb $70
Bottom end bearing and seal kit $60

That would be roughly $615 including the motor. I can't find an overbore head gasket or any aftermarket reed valves though.

[2muchquad]

I will probably use an old rough FMF pipe and fabricate it to fit with whatever FMF silencer I can find on Ebay.

Yeah i hear ya,i have bought literally almost 25 to 30 pipes off ebay,i used these as "stock" whenever i had to custom make a pipe for my frame.As far as the reed goes,i think honda has used the same reed pattern on the cr250 since 1979!You could use almost anything you wanted to,some have had angled carbs some straight etc..2 strokes are easy to work on.Theres stuff for the older cra still readily available,except for the 81 cr450 2 stroke;)

[Project300EX]

Thanks for the help. I'm still looking at that one, but have bid on another motor. It's pretty much the same thing, except an '81. It's in a whole lot better shape too. It also comes with more stuff. Hopefully I'll win the auction, but if I don't I'll just buy the other since it's not an auction. Here's the one I'm bidding on.

http://i4.ebayimg.com/01/i/000/78/bd/7af4_12.JPG

http://i19.ebayimg.com/01/i/000/78/bd/7c39_12.JPG

[2muchquad]

Yeah you could get a motor mount from a early 250r 4 wheeler and then you would have a pivot mount for your swingarm.That motor "looks" better but its the internals that count;)

[Project300EX]

Originally posted by 2muchquad
Yeah you could get a motor mount from a early 250r 4 wheeler and then you would have a pivot mount for your swingarm.That motor "looks" better but its the internals that count;)


The motor's in good shape. It shows a pic of the cylinder and there aren't any guages in it. It just needs some rings. They were took out because the ring gap was wrong and it was losing compression.

Here are some internal pics.
http://i18.ebayimg.com/01/i/000/78/bd/8810_12.JPG

http://i22.ebayimg.com/03/i/000/78/bd/8990_12.JPG

[2muchquad]

If you can get it then go for it:)

[Project300EX]

Oh yeah. Do you know if the Cannondale rear would bolt up? I did a little research and it seems like it would be a pretty nice setup.

[Project300EX]

Also 2muchquad I was wondering if you could give me some tips on this. I know you did the CR on your blaster, so you should have some experience. How did you do your mounts? What all did you do to minimize vibration? What radiator did you use? Gearing, wiring, etc.? Thanks again.

[Project300EX]

Originally posted by Project300EX
Also 2muchquad I was wondering if you could give me some tips on this. I know you did the CR on your blaster, so you should have some experience. How did you do your mounts? What all did you do to minimize vibration? What radiator did you use? Gearing, wiring, etc.? Thanks again.

Bump for this info.

[Project300EX]

I lost the bid on that '81, but I did just win a bottom end. It's an '86 and I won it for $10.50. :eek2: Hopefully it won't be too good to be true. The guy has a good feedback, so it should work out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=005&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=150064726020&rd=1&rd=1

[Project300EX]

Also any of you gurus know what year parts will fit on an '86 or if any other jugs will bolt on? Thanks.

[2muchquad]

You can use the cylinders up to 91 i think as they were ATAC equipped(automatic torque amplification system) powervalves while the 92 and up were the HPP(honda power port) power valve.You can use the cylinders from a 250r as well,make sure you use a certain year(i forgot) because if you dont you'll have to run a spacer plate which FTZ sells.At least with a 250r cylinder they already have the flanges for the 250r exhaust.Hell i would have bought it for that price and im not even looking for one.:D

[Project300EX]

Originally posted by 2muchquad
You can use the cylinders up to 91 i think as they were ATAC equipped(automatic torque amplification system) powervalves while the 92 and up were the HPP(honda power port) power valve.You can use the cylinders from a 250r as well,make sure you use a certain year(i forgot) because if you dont you'll have to run a spacer plate which FTZ sells.At least with a 250r cylinder they already have the flanges for the 250r exhaust.Hell i would have bought it for that price and im not even looking for one.:D

Wouldn't it be better to stay with a CR250 cylinder because of the powervalves? According to this site the '84-'85 have the ATAC and the '86 and up have different variations of the HPP. Just wanting to verify everything to make sure I get all the right stuff.

http://www.scooterhelp.com/moto.barrels/honda.cr250.86_87.overview.html

[2muchquad]

It might be true i could be off on my years,i dont work on the older crs everyday.:) Yeah a powervalve would be better but if you cant find a cr cylinder without a giving a left nut then a 250r cylinder is just another alternative:D

[Project300EX]

Originally posted by 2muchquad
It might be true i could be off on my years,i dont work on the older crs everyday.:) Yeah a powervalve would be better but if you cant find a cr cylinder without a giving a left nut then a 250r cylinder is just another alternative:D

Yeah. I know what you mean. I'm watching a few. Maybe I can find me another good deal.:devil:

[GPracer2500]

The early HPP systems where overly complicated, IMO. It's hard to get them assembled right and if done wrong the rack and cam spindles can be damaged. Then they never work right even if you do get them assembled correctly. I've worked on the 88-91 system (the exterior looked the same/very similar to the pics in that link--I don't think there where major design changes 86-91) and it was a nightmare to get it to operate correctly.

I've also worked on the powervalve system from 92 to 96 and they are MUCH friendlier. That's just FYI though--I doubt a 92-96 cylinder would fit an 86 bottom end.

[Project300EX]

Originally posted by GPracer2500
The early HPP systems where overly complicated, IMO. It's hard to get them assembled right and if done wrong the rack and cam spindles can be damaged. Then they never work right even if you do get them assembled correctly. I've worked on the 88-91 system (the exterior looked the same/very similar to the pics in that link--I don't think there where major design changes 86-91) and it was a nightmare to get it to operate correctly.

I've also worked on the powervalve system from 92 to 96 and they are MUCH friendlier. That's just FYI though--I doubt a 92-96 cylinder would fit an 86 bottom end.


Do you know what all topends will fit the '86?

[2muchquad]

I doubt a 92-96 cylinder would fit an 86 bottom end.

no they wont but ANYTHING can be done if your determined.Go with a cylinder from the 86 on up if you can or the 250r.i think 91 is the last yr that will bolt on if im not mistaken.

[Project300EX]

Okay, so for CR250 cylinders/heads I need to go with '86-'91. And the same years for the 250R/ATC250R?

That's pretty good news, since I'm seeing a decent amount of those years.

[Project300EX]

I finally got a response after asking for the shipping quote twice. She told me her husband traded it off and she didn't know. That's horse ****. I guess it had nothing to do with her not getting the bid she wanted for it. I hate it when people put stuff up without a reserve and get all butthurt because they don't get enough out of it. I'm definatly going to be watching Ebay and waiting for her to put it back up, then I'm going to raise some serious hell.:rolleyes:

Edit: I just talked to a guy and I might be getting a YZ400F motor and harness for $150. I'm so siked, I can't wait for him to call back.

[2muchquad]

I would definately file a complaint with ebay and give that clown negative feedback,thats bullshyt!I hate when they dont get what they wanted for it and try to flake out.Email him and say you want the item or else your gonna leave negative feedback,dont be afraid to leave a negative,otherwise he'll do it again:mad: