CBR250 Forums banner

CRM250AR the Honda oddball

6505 Views 24 Replies 6 Participants Last post by  mekros
I'm a sucker for punishment.... The RGV is on hold since I had to move interstate, it's now being babysat by a friend who has too many RGVs.

I've settled into life in NSW reasonably well and thought I would have a change in riding style and go the dirt bike/motard path (Yamaha WR250R).A few other friends in Melbourne decide the same thing and a bike is spotted up here that he wants, no problems, I can store it temporarily. The deal is done, a price is worked out and the bike lands at my place. A month later said mate says he will long term run into financial problems. I decided to take on the bike and fix it up, decide what to do later. Besides, who can resist a two stroke, especially one that has a reputation for being different.

So the bike is a 1997 Honda CRM250AR. It's a two stroke single, with "activated radical" technology. So at low throttle openings it closes the exhaust port to next to nothing, raising the compression to use the waste heat and unburnt fuel to cause compression ignition (diesel along). Once you get on the gas, it behaves like a normal spark ignition engine and powers along, so in theory you get the best of both worlds.

(space reserved for a picture of the bike when I find it from the archives somewhere)

The fun starts with the bike itself. It has an ADR compliance plate, but was imported as a bike from the UK. I don't know how it works, but it has the plate and engine number so when I register it later I'm not complaining.

Over the long weekend period I decided to break from the family routine and get some shed time. In next to no time it is stripped down.

This is what I achieved:

corroded exhaust and suspension link

A lot of help from liquid spanner

Remembering to be methodical


...and tagged

end of day 1


Slow progress time because it is spent cleaning

first round of cleaning the expansion chamber from this...

...to this

Honda dirt bikes from the same era have a dreaded reputation of seizing their swingarm pivot bolts. I seemed to have lucked out and with a bit of cleaning the bolt is at this stage
See less See more
  • Like
Reactions: 3
21 - 25 of 25 Posts
Whilst I was waiting for bits to come in:
My second child was born, now that means even less time to tinker and ride :eek:
A set of Sun branded XR400 motard rims were bought at a cheap price from a guy that decided to part out his bike.

I've been playing around with what can restore colour to faded plastics:

I learnt that Honda did a swifty with the headstem bearings so you have to be on your toes when ordering the generic part.
When the parts arrived, a local workshop was kind enough to let me use the press so the linkage and headstem bearings are back on, the path to reassembly has begun.
See less See more
Oh boy, can you do me a massive favour? I bought a 99' CRM which apparently had a swing arm replaced. Now, the previous owner also mentioned the linkage bearings need replacing and rightfully so because they were utterly destroyed. So I get home and I'm trying to just put it back together so I can keep it as one piece til I have enough time to work on it and no matter which way I try and installed the linkage and shock, it won't line up with the swing arm. I noticed that there was a "Pro-Link" sticker on the swing arm which I had also seen on my mate's '84 CR500. A little research showed me that the first model of the CRM had that and the swing arm/suspension was different. think the previous owner bought the wrong swing arm but I need someone to take some measurements for me. Would you be able to get these two measurements for me? http://i.imgur.com/5FAiPHY.jpg I would be greatly appreciative if you can. No need for dead accuracy, just to prove or disprove my theory. If it wasn't for this my AR would be registered and riding by now!
Rough measurements by eye and using tape measure...

Swingarm pivot to suspension link is 190mm

Protrusion of suspension link is 20mm
I got a chance to work on the bike a fair bit and bearings were pressed in or fitted

Fitting the lower steering race was interesting.

motard wheels test fitted.

I have three front brake calipers and all of them have different problems so none of them are optimal. I need to rebuild one set. The clearance between the caliper and the rim means it is an outright pain trying to take them on and off, I’ll have to have a motard set up and a dirt set up.
See less See more
ok, progress has seriously slowed down with an increase in responsibility at work and two children really do suck up all free time.
I've managed to source some electrical connectors, snap the head off the rear brake bleed nipple after flushing the fluid (drained it by undoing the brake line banjo bolt initially), and some other trouble with the front brake.
](*,) The fun of restoration.
8 months of progress and no posting....shame on me.

I managed to slowly chip away at things, replaced the the brake caliper with the snapped bleed nipple, threw away my good speedo cable (that was a moment in stupidity), crimp new connectors onto the electrical plugs that were stuffed and assemble it into what resembled a working bike.

A CR250 was sourced (the last of the steel framed beasts) and I'm comparing them side by side to see what of the CR I can use on the CRM for cheaper parts.

A few more months in between.

Fresh fuel into the tank and into reserve mode.....she smokes! All the indicators are on??? None of them flash? More head shaking and laughing at the irony and delay to registration.

I then have to move (again), this time to the foot of some local mountains where I'll get to enjoy some twisty riding and the bike is now waiting for a mate to bring around a power supply so I can do some electrical fault finding.
21 - 25 of 25 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.