- service honda cr 250.jpg (75.06 KiB) Viewed 9264 times
92-01 engines were cylinder reed engines and had a mechanicaly operated power valve, many believe that the 2000/01 cr 250 was the best cr 250 engine to date, and service Honda uses them in all the current 250 2 stroke bikes.
02-07 Honda totally redesigned there engine to a case reed and electronic operated power valve, and unfortunately dropped the ball , as they never came close to winning another 250 test ever again. they refined the motor a little each year, but by that stage all the funding was going towards the 4 stroke boom, it wasn't a bad engine, its just the engines before it were a lot better and refined.
the frame conversion was dead easy, and so many people had done it with great results, Hondas best handling 250 with there best engine
I bought a 06 frame from ebay and had it powder coated, and the next few months started buying bits and pieces of ebay and gum tree, there was never any shortage of parts because 02-07 cr 250r shares suspension, swing arm, forks wheels brakes, with 04-08 crf series. parts were cheap and easy to find.
another advantage to the 92-01 engine is that essesntially the bottom ends are all the same with only ,minor updates throughout the years, so you can change your motor as much as you like with cylinder swaps, providing you use the correct head/piston and cdi ( cr 250 piston changed to a flat top piston in 97) I found a 97 bottom end with a new crank kit installed for a good price , i also installed a new clutch basket and clutch plates. I managed to find a brand new 2001 cylinder on ebay that had been sitting in someones garage for 13 years. I didn't get it for a bargain but stll less than half of what Honda dealer wanted
, it also came with a brand new head . Im also running a 9 oz stealthy flywheel weight, most of the riding I do is enduro The powervalve assembly was also easy to source because it never changed from 92-01, I also went with a wiesco forged piston kit. the only part I struggled with was an 01 cdi, it is now an obsolete part and trying to find a clean used unit was not easy , I ended up paying top dollar for one, [/attachment]
the 2001 motor fits straight in, no modification to the swing arm axle, or the bottom engine mount, the fit perfect ! the front engine mounts on the upper frame need to be opened slightly with a dremmel in order for the front motor mount to line up, different head stays have to be fabricated or can be bought off ebay.
its also worth noting that the 92-01 motor is longer than than the 02-07, and can be only installed through the left side , I shortened the engine a few mm at the back where the carb hoses run between the spring swing arm and motor to stop them being pinched.
you also have to run the 2001 rads, as the water pump outlet is in a different position on the 02-07 rads, but the bolt mounting pattern is the same, so they bolt straight on.
99/2000 cr 250 ran pwk 38 air striker carb,. which is what wanted instead of the mikuni tmx Honda ran from 01-07. so I bought a 2000 air boot just for a better fit. the bolt pattern is the same from the airbox to the air boot, no adapter plate required
The01 cdi is a different size to the 02-07 cdi, so and 01 cdi bracket is needed , but good news again!, whilst the brackets and cdi are different sizes, the bolt mount pattern is the same,, it bolts straight on behind the front number plate !
the 2001 expansion chamber also shares the same mounts as the 02-07, and bolts straight on,, however! he silencer does not. you have to run an 05-07 cr 250 silencer, I found this out the hard way.
I used a 02 kick start ,but had to grind a few mm away from the shaft as it would get caught on the frame, from what I know any year cr kickstart will fit, and has the same problem
and that's it , all in all its a very easy mod for a first timer like me , the bike rips !! and handles like a dream. it has no trouble rounding up 4 strokes in the bush. I would have liked to have posted more pictures but I had trouble uploading more than 5 , so I just posted the mods needed. if anyone has any questions feel free to contact me
.. ps I also have gold rims , just saving the bucks for talon hubs and to have them laced to finnaly finish off the retro look
