CR(M)250AR SUPERMOTO BUILD
CR(M)250AR SUPERMOTO BUILD
Hey fellas,
Thought it would be a good idea to fill this forum up with builds to try and expand the resources available here.
This is my short term project designed to build up my two stroker skills and to keep me patient while im between built trips to Newcastle to work on my KTMito . (im dieing to get back on the track on any bike!)
I bought a Honda CRM250AR 1999 from Newcastle 4 months ago, and managed to bring it home to Melbourne recently where I took it for a few rides and diagnosed problems that needed tending to.
first things first...
For those who dont know, the CRM250AR was the production version of the EXP-2 Enduro prototype that used Active Radical Combustions to decrease emmissions.
The bike at low revs and low throttle openings closes and exhaust flap (hondas fancy word por PV) and introduces hot exhaust gases back into the cylinder to become thousands of tiny spark plugs (known as Active Radicals).
Therefore the Spark ignition is no longer required, the engine 'diesels' as it undergoes controlled detonation combustion.
When Undergoing AR combustion the engine purrs steadily without the expecting 'ring-ding-ding' unsteady combustion cycles common in two strokes. its almost akin to a four stroke.
Crank the throttle open and the engine comes to live with potency close to a CR250 honda.
Now that your all up to date with the CRM history, here is the low down on my build progress.
I dont have much spare time so this post might be a bit erratic and not in a particular order but I just dont have the time right now haha please just appreciate it for what it is
The ancient knobbies were removed and replaced with Pirelli Scorpion road tyres.
Forks serviced with fresh oil; more viscous and higher oil level to increase air spring effect toward the end of travel.
preload on shock increased
new brake pads
Fresh brake fluid
sanded back all plastic panels with wet and dry, I am making replica decals using white and black 3M Di-Noc Carbon Fiber
and am going to prepare the panels to make them nice and shinny using a new product I found called Novus, for plastic polishing (usually pinball machine perspex)
then I pulled the engine out, after 3 weeks of trying to bash out the siezed swing arm pivots. Replaced the swing arm bolt, the two bushes, the four bearings, the four seals and the nut, after covering with heaps of grease
pretty bad hey!
Touched up the frame paint using a paint texta as a primer, and later on I will touch up with a proper enamel and clear coat. just wanted to touch it up and prevent the rust for now.
removed the triple clamps and steering stem, punched out the races and replaced with some new after market bearings.
pulled the engine down, left the top end with Lozza after an encounter with airport security that one could only describe as interesting as I tried to go through baggage check with a big lump of aluminium two stroke goodness in my bag.
sanded and repainted the engine covers in a less 'plastic' looking gold
hit the engine cases with a stainless wire brush to remove 10 years of grit.
I was very happy with the brushed aluminium look that I got after a half hour of rubbing.
got a wossner piston on the way to replace the cracked piston that was in the poor girl
Shes also getting all new seals throughout the engine and new crank bearings.
Got a Vforce3 reed intake and am replacing the 32mm PE carb with a PWK38
And modified intake boot to suit the cr250 vforce
The bike already has a pro-circuit pipe and a mugen (honda's version of yoshimura) muffler
aswell as a mugen shaved head and a mugen racing ignition.
I had an issue with a leaking carb warmer line so I removed this with a m5 thread taper, a stainless bolt and some Wurth purple goo
after pulling the clutch apart I found that it was heavily grooved and required filing down to make smooth. should last another 5000ks or so before she needs replacing with a new one.
See the odd scuff marks on the outside of basket, any idea what this is from? Im clueless what caused this? any reason for concern???
In terms of gearing, I am reverting back to the OEM 14/42 gearing which is good for 150kmh as the CRM250AR has an overdrive 6th gear. these are OEM sprockets with a 520 Oring chain.
I should have the bottom end back this week sometime after I sent it to a mate to have the fly wheel pulled, the cases split and the crank bearings pulled. I hope to be able to do this in the future but Im just slowly getting my garage together with the tools I require.
Then she is 100% ready to put back together apart from the top end.
I am hopeing to have her back together and running for a trackday in mid May at Broadford.
Breaking News; Bottom end is done and getting it back tomorrow night!
very good news
Thought it would be a good idea to fill this forum up with builds to try and expand the resources available here.
This is my short term project designed to build up my two stroker skills and to keep me patient while im between built trips to Newcastle to work on my KTMito . (im dieing to get back on the track on any bike!)
I bought a Honda CRM250AR 1999 from Newcastle 4 months ago, and managed to bring it home to Melbourne recently where I took it for a few rides and diagnosed problems that needed tending to.
first things first...
For those who dont know, the CRM250AR was the production version of the EXP-2 Enduro prototype that used Active Radical Combustions to decrease emmissions.
The bike at low revs and low throttle openings closes and exhaust flap (hondas fancy word por PV) and introduces hot exhaust gases back into the cylinder to become thousands of tiny spark plugs (known as Active Radicals).
Therefore the Spark ignition is no longer required, the engine 'diesels' as it undergoes controlled detonation combustion.
When Undergoing AR combustion the engine purrs steadily without the expecting 'ring-ding-ding' unsteady combustion cycles common in two strokes. its almost akin to a four stroke.
Crank the throttle open and the engine comes to live with potency close to a CR250 honda.
Now that your all up to date with the CRM history, here is the low down on my build progress.
I dont have much spare time so this post might be a bit erratic and not in a particular order but I just dont have the time right now haha please just appreciate it for what it is
The ancient knobbies were removed and replaced with Pirelli Scorpion road tyres.
Forks serviced with fresh oil; more viscous and higher oil level to increase air spring effect toward the end of travel.
preload on shock increased
new brake pads
Fresh brake fluid
sanded back all plastic panels with wet and dry, I am making replica decals using white and black 3M Di-Noc Carbon Fiber
and am going to prepare the panels to make them nice and shinny using a new product I found called Novus, for plastic polishing (usually pinball machine perspex)
then I pulled the engine out, after 3 weeks of trying to bash out the siezed swing arm pivots. Replaced the swing arm bolt, the two bushes, the four bearings, the four seals and the nut, after covering with heaps of grease
pretty bad hey!
Touched up the frame paint using a paint texta as a primer, and later on I will touch up with a proper enamel and clear coat. just wanted to touch it up and prevent the rust for now.
removed the triple clamps and steering stem, punched out the races and replaced with some new after market bearings.
pulled the engine down, left the top end with Lozza after an encounter with airport security that one could only describe as interesting as I tried to go through baggage check with a big lump of aluminium two stroke goodness in my bag.
sanded and repainted the engine covers in a less 'plastic' looking gold
hit the engine cases with a stainless wire brush to remove 10 years of grit.
I was very happy with the brushed aluminium look that I got after a half hour of rubbing.
got a wossner piston on the way to replace the cracked piston that was in the poor girl
Shes also getting all new seals throughout the engine and new crank bearings.
Got a Vforce3 reed intake and am replacing the 32mm PE carb with a PWK38
And modified intake boot to suit the cr250 vforce
The bike already has a pro-circuit pipe and a mugen (honda's version of yoshimura) muffler
aswell as a mugen shaved head and a mugen racing ignition.
I had an issue with a leaking carb warmer line so I removed this with a m5 thread taper, a stainless bolt and some Wurth purple goo
after pulling the clutch apart I found that it was heavily grooved and required filing down to make smooth. should last another 5000ks or so before she needs replacing with a new one.
See the odd scuff marks on the outside of basket, any idea what this is from? Im clueless what caused this? any reason for concern???
In terms of gearing, I am reverting back to the OEM 14/42 gearing which is good for 150kmh as the CRM250AR has an overdrive 6th gear. these are OEM sprockets with a 520 Oring chain.
I should have the bottom end back this week sometime after I sent it to a mate to have the fly wheel pulled, the cases split and the crank bearings pulled. I hope to be able to do this in the future but Im just slowly getting my garage together with the tools I require.
Then she is 100% ready to put back together apart from the top end.
I am hopeing to have her back together and running for a trackday in mid May at Broadford.
Breaking News; Bottom end is done and getting it back tomorrow night!
very good news
Last edited by Jeram on Sat Nov 26, 2011 4:06 pm, edited 1 time in total.
Re: CRM250AR full rebuild from the ground up
After speaking to the old man, we seem to think that the clutch is in the condition it is due to something in the engines past which has since been fixed.
ie: loose clutch hub cause clutch to rub on primary gear (OUCH!!!)
or shattered clutch plates flying around inside the side cover.
I think its the first of the two
ie: loose clutch hub cause clutch to rub on primary gear (OUCH!!!)
or shattered clutch plates flying around inside the side cover.
I think its the first of the two
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
got some graphics for the bike.. going to put black/gold decals to replace the ugly red decals on the radiator shrouds and 3D mugen carbon stickers for the top of the white number boards.
http://i.ebayimg.com/04/!B3UOQMwB2k~$(K ... Hw~~_1.JPG
http://i.ebayimg.com/06/!B1,V1,gEWk~$(K ... w!~~_1.JPG
http://i.ebayimg.com/00/$(KGrHqUOKj8E0v ... 2!~~_1.JPG
http://i.ebayimg.com/00/$(KGrHqQOKioE15 ... V!~~_1.JPG
http://i.ebayimg.com/04/!B3UOQMwB2k~$(K ... Hw~~_1.JPG
http://i.ebayimg.com/06/!B1,V1,gEWk~$(K ... w!~~_1.JPG
http://i.ebayimg.com/00/$(KGrHqUOKj8E0v ... 2!~~_1.JPG
http://i.ebayimg.com/00/$(KGrHqQOKioE15 ... V!~~_1.JPG
Re: CRM250AR full rebuild from the ground up
went got another useful tool today, a 650degree heat gun.
I was impatient to gave it a quick test on one of the side panels today and its true, it does bring back the shine.
now all I have to do is use some wet/dry to get the last few big scratches out, then used the novus 3 to get the medium scratches out, the novus 2 to get small scratches out and the novus 1 to get it really really smooth...
then Ill hit it with the heatgun, the hit with armorall and wax...
should look better than new when done
I was impatient to gave it a quick test on one of the side panels today and its true, it does bring back the shine.
now all I have to do is use some wet/dry to get the last few big scratches out, then used the novus 3 to get the medium scratches out, the novus 2 to get small scratches out and the novus 1 to get it really really smooth...
then Ill hit it with the heatgun, the hit with armorall and wax...
should look better than new when done
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
Those marks on the clutch are in the wrong direction for it to be something scraping while the engine is running.
RD350LC- RGV Mods, PWK28's
RZ500 - YZR Replica, PWK28's
RZ500 - YZR Replica, PWK28's
Re: CRM250AR full rebuild from the ground up
New theory, do you reckon some idiot was filing the clutch gears?
haha
got some more bits for the bike in the post this week.
my plastic repair kit
Rubber Mikuni jet holder/case with a heap of jets in it
more fork oil to top it up to the right level
fuel filter
shitty news is that the ebay seller who I got the bearings off sold me CR250 crank bearings, seller is now being an arsehole saying that he wont accept a refund unless in original packaging... farked if I know what happened to those little Honda parts bags. Paypal has forced the refund but unless I send it back to him in 10days in the same condition I received it in I wont get my refund and the arsehole seller will then have my money and the bearings.
haha
got some more bits for the bike in the post this week.
my plastic repair kit
Rubber Mikuni jet holder/case with a heap of jets in it
more fork oil to top it up to the right level
fuel filter
shitty news is that the ebay seller who I got the bearings off sold me CR250 crank bearings, seller is now being an arsehole saying that he wont accept a refund unless in original packaging... farked if I know what happened to those little Honda parts bags. Paypal has forced the refund but unless I send it back to him in 10days in the same condition I received it in I wont get my refund and the arsehole seller will then have my money and the bearings.
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
oh, and now I have to wait 2 weeks because the bearings I need are on back order from Honda.
so hes not only sold me the wrong bearings, hes refused the refund, cost me an hour in mechanics labour (installing wrong bearing) and delayed me 2 weeks.
so hes not only sold me the wrong bearings, hes refused the refund, cost me an hour in mechanics labour (installing wrong bearing) and delayed me 2 weeks.
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
while waiting for my bearings to turn up so was a bit bored haha
Re: CRM250AR full rebuild from the ground up
got my engine old bearings ripped out, new bearings put in, and the crank pressed into the half case... all up $100 plus labour, and cleaned my cases for free
Im very happy, I didnt even snap at them for taking two weeks to do it
Got it home, was meant to be completing uni projects today, but I couldnt help myself...
gearbox in, tested all the gears 5 or six times, popped the other case half in the oven...
NOTE TO SELF: dont put it in upside down in oven ever again, main bearing fell out in oven lol and I had to get it back in
then the two case halves came together with ease, then I bolted the two halves together and installed all the seals
now I just have to do the alternator, counter balancer, shift shaft, clutch and primaries gears... then its time to put her in the frame
Im flat out so will save that for next weekend (I by that I mean Ill end up out there tomorrow most likely haha)
Im very happy, I didnt even snap at them for taking two weeks to do it
Got it home, was meant to be completing uni projects today, but I couldnt help myself...
gearbox in, tested all the gears 5 or six times, popped the other case half in the oven...
NOTE TO SELF: dont put it in upside down in oven ever again, main bearing fell out in oven lol and I had to get it back in
then the two case halves came together with ease, then I bolted the two halves together and installed all the seals
now I just have to do the alternator, counter balancer, shift shaft, clutch and primaries gears... then its time to put her in the frame
Im flat out so will save that for next weekend (I by that I mean Ill end up out there tomorrow most likely haha)
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
was a bit skeptical of my big end bearing...
so I made a video and sent it to lozza...
got the dreaded reply "Its fucked"
so I had to pull my cases back apart and am going to send her off for a new bearing, washes and if the pin needs doing also that will be done.
shouldnt slow down the build too much coz i still havnt got my top end back.
atleast now Ill know that the engine has been completely rebuilt and nothing should go wrong for a long time
so I made a video and sent it to lozza...
got the dreaded reply "Its fucked"
so I had to pull my cases back apart and am going to send her off for a new bearing, washes and if the pin needs doing also that will be done.
shouldnt slow down the build too much coz i still havnt got my top end back.
atleast now Ill know that the engine has been completely rebuilt and nothing should go wrong for a long time
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
The "scuff marks" on the alloy clutch basket are caused by the tool the factory uses to remove the casting "flash" or excess material which is present during the manufacturing process. The tool is something like a thick circular bandsaw blade and it is pushed over the outside of the basket to simply and quickly broach away excess material. Most baskets from most manufactures have a similar marking on their baskets, but not as wide and defined as your one. The RD/RZ baskets have marks but only 3/4mm wide, not 8/10mm like yours, so they don't usually stand out like dogs balls like yours.
Graham
Graham
Re: CRM250AR full rebuild from the ground up
Thanks graham, that solves that mystery
looking forward to getting my hands on a YZ490 rod
looking forward to getting my hands on a YZ490 rod
Re: CRM250AR full rebuild from the ground up
this build just got very serious
YZ490 rod
2005 CR250 cylinder
KTM250SX oversized piston
Zeeltronic
CR pipe
PWK38
268cc of pure carnage!!
Should make for some serious fun !!!!!
YZ490 rod
2005 CR250 cylinder
KTM250SX oversized piston
Zeeltronic
CR pipe
PWK38
268cc of pure carnage!!
Should make for some serious fun !!!!!
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
Re: CRM250AR full rebuild from the ground up
here is my cylinder... looks very very clean and freash !
2005 CR250 cylinder with PV, its freshly plated and bored out to my specific size.... what a bargain!!!
2005 CR250 cylinder with PV, its freshly plated and bored out to my specific size.... what a bargain!!!
the following 4T propaganda was brought to you by your local 2T lobby group...
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "
"whats that youve got there?... a 450? "
yeah...
"what cereal packet did that come out of? "
huh?...
"I just wanted to know, because theres nothing worse than finding a piece of shit in the bottom of your corn flakes. "