[nigel cooper]

Thanks guys for the comments,The inner tube idea sounds interesting and easy to try.I have already started building my own muffler.Its 32″ long,3″ diameter running along the rear end from a silicon tube from the end of the piping with a large 90 degree bend before it enters my muffler.basically just copying the RLV muffler-just making it longer.Will try the”honk tube” on the end though just to see what happens.

[nigel cooper]

yikes! seize it!! will definetly remove the oil and even put a label on it as well.thankyou

[nigel cooper]

stock ignition setup,sharkshifter mount / 92mm x 31.3mm,totally stock engine except for the carbs main jet and needle/float (Ians recommendation) and cylinder head(volume removed by Ian at Viper as per his recommendation)kick start items removed and hole plugged.I can send you pictures if you like.Just pm me.thanks

[nigel cooper]

brilliant product! Using/reusing existing Honda parts from your engine makes the most sense to me and it can save you about 1/3 of the cost.Why re-engineer and manufacture new components that are proven,already and easily accessible.Just change only what needs to be changed from the CR250 engine.

Does it have an external water pump and how much does the engine and exhaust weight?

Could anyone in north america purchasing one, post your opinions on it after trying it out? Vibration levels,smoothness,power and torque ect.

[nigel cooper]

Does it have 6 gears and a counterbalance shaft?

[nigel cooper]

I think thats a great find.Wish  I had one.I think you can get replacement parts via Britain.More qualified guys will have more to say.

What ever happened to your Honda fuel injected  4 stroke CBR125 sportbike engined shifter kart?  That was a real nice piece of machinery!

[nigel cooper]

wow,that engine has been my dream engine since it came out.I just cant afford it.($6000 US I think)I figured it would be bulletproof.Just a simple 2 stroke engine with no gears,just a couple of counterbalance shafts.Nothing new-just plain old fashioned big displacement.

Any chance you can run it direct drive and bypass the clutch issues that you have been having?You could save a little weight by getting rid of the starter and battery but you would need a push start.

If it wasnt for the clutch and the difficulty in getting your gears,which it sounds like you did eventually get overseas,would you be real happy with it?

[nigel cooper]

I have mine mounted on a little aluminum plate held in place by 2 of the boot bolts.The coil is fastened to two vibrasorbers on the plate with a grounding strap.

[nigel cooper]

If you have the time,and feel like going through the old forum archive,you will find a few dyno curves posted by Ian at Viper,I remember there was one of his race engines and it was 62 hp,32ft/pounds torque,but  I dont recall the max rpm.There just happened to be a curve of an almost stock 2001 cr250 posted which was perfect for me.

[nigel cooper]

that horsepower and rpm seems low.The charts that I have seen on the forum for a mildly tuned 2001 CR250 are 55HP at 9500 and the curve up to that point is quite linear? And with a new box you get another 5hp and another 500 rpm with the same engine.

How does the kart compare to your CRF250 kart?

[nigel cooper]

thanks for the reply Brian,I chose not to go the RAD valve route,(for now)as I think it will be more than enough HP stock for me to handle I can always change it later.I left in the powervalves as well.Sorry to hear that your not happy with how the project turned out compared to a 125.From my notes on older posts I believe the next step would be replacing the stock Honda ignition module with a Viper racing one.

[nigel cooper]

same place as on a cr125,downstream of the reed cage on the side that your pump is going to be on.Whatever happened to your CRF250 kart from a few years ago? You sure did a nice job on it,the pics of it looked great.(I think it was yours?)

 

 

 

 

[nigel cooper]

if you have not, check out the link in this forum “All things CR250” and the Classic forum archive.Very helpful and interesting.There are a couple of excellent posts by Ian Harrison of Viper Racing regarding your topic-spark plug choice,needle/seat,powervalve ect.

Something to consider is how you will be starting the engine.

[nigel cooper]

Thanks Ian

when I was rebuilding a cr125 a couple months ago,the Honda dealer advised me that there is only an A piston available as the B piston had been superceded by the A piston.After getting off the phone with Honda today I asked him about the 2001 CR250 pistons,same thing, only an A available.

I guess in Canada it is A only.If I end up needing a B I will have to buy from another country and have it shipped instead of picking it up in person.

 

Merry Christmas everybody!

nc

[nigel cooper]

Thanks Ian,

I was not sure if Honda had done away with the 2 sizes like they did with the CR125.

What about cylinder to piston clearances?      .06  to .075mm?

[nigel cooper]

Save yourself money,grief and frustration.Sell the engine and buy a CR250 setup.Same power,less weight,smaller engine and kart parts/accessories  are available.Thats my opinion.

[nigel cooper]

thanks Chris,I had a feeling the guy was way off. Finding hp/torque/dyno charts for honda motors online is easy.The TM engines dyno results are hard to find,must be a secret.

[nigel cooper]

Thanks again Ian,

I guess Ill have to get them from honda.Im buying bearings often at work and can get great prices for myself due to the money we spend at our supplier,but I learned from a previous post of yours that the CR250 crank bearings are special and I must have them.(PS. turns out I`ll have to buy a honda crank as well.When I got the engine apart I was shocked to find a Wiseco crank.I was assuming a honda crank and sending it out for rebuilding)oh well,i have all winter

 

nc

 

[nigel cooper]

checked with senior parts guy on the way home,only one piston available.

[nigel cooper]

thanks Troy,

it does help a bit.Honda told me that they had 2  pistons? Same part numbers except a D on one number ?I will be back there next week and get some part numbers from him and let the forum know what I found out.

[nigel cooper]

Thanks Ian,

amazing info again from the wizard of all thing Cr250. I`m leaning towards a rebuild of the existing crank by ken oconner racing.He has a youtube video explaining how he rebuilds them(special jig),uses the japanese pro-x parts (like you mentioned) and his website has an article explaining what you have said and the tolerances he has the crankshafts leave his shop.It really does look like he knows what he is doing.For $150 us dollars,plus shipping,I am ,at this point considering this option,if not-buy a new one.Either way  I will be checking it on my own vblocks before installing it.

[nigel cooper]

its a 2001,even on ebay with shipping and customs it still would come out to over $400 (can)

 

 

 

[nigel cooper]

Thanks Steve for the quick reply.I checked it out like you wrote and sure enough,on a 1996 part diagram they show the spring and washer!!Hurray,back to Honda tomorrow to order the parts.I want a spring on my engine.

 

thanks again

[nigel cooper]

I really liked what Eric Davis had to say on his post.I was really interested in comment #4.

Why did cr250 sprints not take hold? Cheap and big power? To me its seems the way to go

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