Thumper Club Forum
Technical => Project Progress => Topic started by: Moto63 on May 29, 2025, 03:42:11 PM
-
Having bought the Honda cb250rs from Kev(Berlin) last week, I’ve had a couple of small outings on it. Lovely bike, definitely as good as remembered mine to be back in the early 80’s.
So....Why not build a lovely little rs250 street tracker🤔 I already had a few RS bits kicking around in my garage. So I’ve decided I’m going for it. The big thing I need is an rs250 engine, no immediate panic as I can use the one from Kevin’s bike as a mock up for the time being. I’ve already gathered a lot of bits to get a rolling chassis. I’m taking a lot to be soda blasted next week. Then the tug welder will be getting some use. I’m afraid I don’t know how to post photos. Especially now my go to man Mathee has generally left the site. He used to do them for me.
I fully intend to have this one finished within 5months, ready for winter...oh and hopefully the Stafford show 🤞
Cheers, Michael
-
Aye Michael,
OH! Really? Hovering mudguards and all! ;) ;) ;)
I'd be willing to post up your images or give a bit of tutelage, if you would prefer?
Crack on, Bill
-
Aye Michael,
OH! Really? Hovering mudguards and all! ;) ;) ;)
I'd be willing to post up your images or give a bit of tutelage, if you would prefer?
Crack on, Bill
That would be most appreciated Bill, thanks.
No levitating mudguards on this one though, just a nice ally fixed one 😁.
My plan is to crack on with this one, ready for winter. Then over the winter months I’ll crack on and get the XBR tracker finished.
I can email photos, just don’t know how to post them on this site. So if you don’t mind me emailing you some pics from time to time, that’d be great 👍
Cheers, Michael
-
PM'd you.
Bill
-
Having bought the Honda cb250rs from Kev(Berlin) last week, I’ve had a couple of small outings on it. Lovely bike, definitely as good as remembered mine to be back in the early 80’s.
So....Why not build a lovely little rs250 street tracker🤔 I already had a few RS bits kicking around in my garage. So I’ve decided I’m going for it. The big thing I need is an rs250 engine, no immediate panic as I can use the one from Kevin’s bike as a mock up for the time being. I’ve already gathered a lot of bits to get a rolling chassis. I’m taking a lot to be soda blasted next week. Then the tug welder will be getting some use. I’m afraid I don’t know how to post photos. Especially now my go to man Mathee has generally left the site. He used to do them for me.
I fully intend to have this one finished within 5months, ready for winter...oh and hopefully the Stafford show 🤞
Cheers, Michael
Michael.
I’m glad all is well with the Cb250rs.
You realise, of course, that you are now a hostage to fortune as a result of “finished within 5 months, ready for winter…….and hopefully the Stafford Show”.
The performance police will be monitoring you closely.!
😂😂😂😂
-
Kevin.
Given that my xbr650 Tracker has been on the bench for the last ten, yes ten, years. 🙄🤣 I think I need the “performance police” on my case. Keep me in check.
In my defence, regarding the XBR tracker taking so long. I had just started it when I had my accident. That put paid to just about everything for about 8 to 10 months. Then being a gluten for punishment, I decided to take on our house build.
HOWEVER..... I’m obviously all fixed up now, the house build is 99.5% complete. So I can now devote more time back on my bikes.....AT LAST 🙄
Plus, the RS tracker is a far simpler build than the XBR tracker.
I’m really looking forward to getting stuck into it, ideally just need a decent condition RS engine to slot into it🤞
Ps... the XBR tracker is now about 80% complete 😉
Cheers, Michael
-
You could always pop the XBR engine in it. I'm told it's easy.......
-
Well I’m afraid you’ve been misinformed Ian. It’s definitely not easy. The XBR is a traditional cradle type frame. Where as the RS is hung from the main spine under the tank, and bolted through the frame just in front of the swinging arm. It’s the Honda FT500 which is a simpler swap.
Plus I don’t really want that kind of power for this project, it’s essentially going to be ridden during the winter months. So the RS250’s power is ideal.
Cheers, Michael
-
I'm sure you're right, Michael. When I was complaining my 250RS was underpowered that's what I was told!
-
“finished within 5 months, ready for winter…….and hopefully the Stafford Show”.
The performance police will be monitoring you closely.!
😂😂😂😂
I am watching you Michael 🤓
-
Well Ian. I couldn’t wish for a better performance pooleece man to keep his eye on me 👁.
And if the little rs tracker turns out anywhere near as nice as your yams. I’ll be a happy chappie.
I’m hoping it will be a relatively quick build as I’m basically keeping the rs rolling chassis & engine. All fully stripped, blasted & repainted. Then altering the subframe, new seat, different tank.
So nothing like as involved as the XBR tracker.
Anyway. Health permitting, you WILL see me at the Stafford show with it in October.
Cheers, Michael
-
Right.... before I go any further. I’ve had some news regarding the frame I was going to use for this project. Looking extremely likely that it was, at some point a pinched bike/frame. Hence I can’t proceed much further until.
A... I sort this issue out with the dvla
B... I buy another frame + logbook
So... I’m retracting my initial claim of completing this within a 5 month period 🙄🤦???
-
:( OH! A bit like hot copper pipe then?
That really is not a good surprise to have. Maybe finish the 650 tracker, rather than cluttering up the joint, with another load of bits/scrap?
Look after No.1
Bill
-
:( OH! A bit like hot copper pipe then?
That really is not a good surprise to have. Maybe finish the 650 tracker, rather than cluttering up the joint, with another load of bits/scrap?
Look after No.1
Bill
I totally hear what you’re saying Bill. But the 650 tracker has been done to a reasonably high standard. I didn’t really want to take it out in the slimy winter grime.
The idea of doing the RS was that I wouldn’t do it to such a high standard. So I wouldn’t be overly fussed about taking it out during the winter months. Plus the RS’s power is ideal for those slimy, greasy/salted up winter roads.
I’m not giving up just yet. I see it as a set back. A set back I could do without, but a set back. I’m not down and out yet.
Cheers, Michael
-
;D Yorkshire gritstone! ;)
Bill
-
Well.... had a bit of good news today. The frame I’ve got is genuine. Long, boring story which I honestly can’t be bothered typing it all.
Anyway, it’s all systems go now. So I’ll forward Bill a few photos as he’s kindly offered to post them fir me 👍
The performance pooleece can start watching from today because the “different tracker” project is back on 👍😉
Cheers, Michael
-
Michael's post and images.
"Here’s the first pic of the RS tracker project. A butchered frame, swinging arm and wheels.
For all the purists out there, the frames sub-frame had already been removed before I got it. I’ve
just removed the brackets that had been welded on. I now intend to get it all over to the soda
blasters, then once back I’ll fabricate a new rear sub-frame and take things from there.
I hope the performance pooleece will be on the ball to keep me on my toes 😉?"
Uploaded by Bill
-
👍
-
Rapid acquisitions! 2 posts, the first of a manky engine, the second after pressure washing.
Michael's notes follow:
"The engine I bought off fleabay arrived this morning, it was exactly as the seller had described,
pretty tatty looking but you could tell it wasn’t quite as bad as it looked under the grime. Here are 5
photos of the offending item. I think there’s two before and three after it had undergone a quick
degrease and wash. It’s already come up to a reasonable finish. I am just having trouble with the
bottom bolt in the front mounting bracket, seized solid it is. :(
Once I’ve removed the troublesome bolt I’ll give it another good degrease and wash. I ultimately
want to strip it, check it all over internally, refresh it and have the casings re-coated. Sadly the
bloke I used to use is now retired. So if anyone knows of a very good/decent engine builder please
let me know👍🤞
Frame, swinging arm, wheels and a few bits and pieces are now at the blasters getting......eerr. Blasted 😁"
Uploaded by Bill
-
Second post re: engine acquisition images after pressure washing.
Uploaded by Bill
-
Michael, you certainly have the bit between your teeth on this one......I told you I'm watching you 😂
-
Ahh… yes Ian I do have the bit between my teeth with this one. It’s great to be able to finally get back in the workshop and do some messing with bikes. Instead of being consumed by the house build. Yes. I know it’s a first world problem 😏
However. Things on the bike front definitely took a downward spiral yesterday, once I started stripping the engine down. I’m sure Bill will post up the pics in good time. Anyway onward and upward old chap.
Cheers Michael
-
Looky, looky, inside the eBay engine! :o
Well, it's a good job that I took the decision to strip the RS engine I bought off fleabay. Don't think the damage to that piston will polish out do you. So my plan is to fully strip it all. Get all the cases sent for vapour blasting. Then get the engine fully rebuilt. With a shiny new piston. Professionally.
So. I hope the progress poo Leece are taking note of all this work 😁😉
Uploaded by Bill
-
I din't think I've evr seen one quite as bad as that. Meanwhile I'm still string to get the right bits for my little Beeza, at the same time have discovered a stripped thread in the Norton's primary chaincase so that's all in bits. The B'Zuki - so far - is still performing well.
-
Nowt wrong with that piston that a good tig welder can't put right 😉.
Ahhh the joys of buying off eBay
-
Nowt wrong with that piston that a good tig welder can't put right 😉.
Ahhh the joys of buying off eBay
Yeah, I can’t see that polishing out with a dab of solvol can you🤣😜
-
It has been suggested that having tried NO2 fuel by somebody on FB, you might change the ratio! Joolz might care to comment?
Have seen this happen before when running NO2 at 25lbs flow and 100lbs boost
Would recommend running 15/80 next time
Another FB suggestion was that "..... forget the 250 engine and look for an XL500". However, this extra poke is not what is intended, more of a pootler for Pennine byways. ;)
A similar fate has also been experienced by a past owner on FB.
Back in the day that happened to my 2nd RS on the way back from London to Manchester and keeping 65/70 on the road I had forgotten to top up the oil and bike died. Needed new piston. Luckily it did not seize on me it just lost power.
Toodle pip, Bill
-
Is that engine even rebuildable?
-
Take a look at this....
https://www.ebay.co.uk/itm/277188578845?_skw=honda+cb250rs&itmmeta=01JXPVAD8EN5N0YRYB849AKHG0&hash=item4089ba0e1d:g:scQAAOSwIyVoRqWI&itmprp=enc%3AAQAKAAAA0FkggFvd1GGDu0w3yXCmi1cF%2B6Jc6yEFaFZZnNBTRAcBQ%2F59JsTLX7dX%2BFzHsbVjTH%2FcAD8Us6K9W33CPWSVZti9ZK8r%2FP5s9Y5yPrlZS9ZlkAv5%2FHaJ2jV54NzTF%2BwxBodlcUbFmtmoebr34P91uyUj0wC6o6DOEWFmpGthnaocyzp%2Fu4moXJyErwwQG3p3EcCJIsaXD7c7MLZdAgXrzFLD01qT17Vk8DWCNgtIlIWNg0xySJa4u%2B9p8EyVkwNW4gd4mCPfQrdiub67N4%2FKzyY%3D%7Ctkp%3ABk9SR6bUqdvtZQ
-
And this....
https://www.ebay.co.uk/itm/256486015552?_skw=honda+cb250rs+engine&itmmeta=01JXPVH8BNAM37F39F7MV8V5JF&hash=item3bb7c20240:g:1eoAAOSwaj9mI6Uj&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1ehdnUXeQzs7C29NakcpfAGpvaeOaCHGGckJsIHUjvaPWONSKyzeOHrb0DAzADw570Zc7I2M5ZVzDem3torWqxBGyH5VCJsOuuRIk2cYxPpKAMZZoyssn%2FG0wzZhXGgZziPH%2BntXLmxmV1Jc5R6PK4gcUaqIwZtn6NkhVvaKJR%2FsGMECzVIqpEzlGuolZmh%2Br1xditCUlRp8TaHCtgIEZ1NaQei%2BUKjw3S%2BYoxZwnNOZHfVY1OfYqCpYrbdRIDgPktWHxAlT5Qx7gy2XyUfAlgoUhhBcFve3QraE88Nf1gCdw%3D%3D%7Ctkp%3ABk9SR-6HxdvtZQ
-
Is that engine even rebuildable?
Well… ultimately Martin. Everything is rebuildable, all comes down to how deep one’s pockets are really.
Many thanks for both the links you posted. The little cafe racer and the leccy Start engine. I have looked at both previously. The cafe racer I dismissed as I don’t need a complete bike. The engine I dismissed as I figured. That’s another £500 and, again ultimately I don’t know what I’m buying, condition wise. So I’d rather spend that £500 on sorting out the one I’ve already got. I know £500 won’t get the engine completely sorted but will hopefully go a fair way to seeing it running again. I fully intend to keep the “different tracker” once it’s finished, so I want the engine to be of a decent standard, certainly internally.
Thanks again for taking the time to find/post the links up.
I just see the knackered engine as a slight set back.
Onward and upward
Cheers, Michael
-
Good luck with the project Michael. When I first got into RS250s around the turn of this century bikes and parts were dirt cheap. How things have changed. I got 2 massive lots of spares including engines for very little money. If only prices had remained at a reasonable level.
-
Yes. Martin …. Sadly nothing is cheap anymore. 😔
Like you though, I’m thoroughly enjoying riding the RS I bought off Kevin. Lovely, light and nimble. Certainly takes me back to 1981 when I bought one new HVH 212W A red one. Riding it has also made me realise that I made the right decision in selling the grom to buy it. I can definitely see why you’re hanging on to yours.
I’m confident that once I’ve actually built the “different tracker” it’ll be a cracking little bike, properly sorted, definitely a keeper.👍
Cheers, Michael
-
Images of the cylinder head from the eBay engine.
That's the weird thing, the cylinder liner, valves, cam all appear to be in "reasonable" condition. Given the actual engine must be at least 40yrs old.
The first thing I thought when I first clocked eyes on it, was oil starvation, but then on closer inspection of everything else, it almost doesn't tally up. 🤷
Then reading the bit from the bloke on farcebook who says he did the same thing to his going from London to Manchester. Maybe it was simply oil starvation. Guess we'll never truly know. Unfortunately it will just take longer and clearly cost me more money to sort.
I had always intended to strip it, to refresh it generally.
Just got to be a case of onwards and upwards. It was always risky buying it blind, but in fairness to the breaker I bought from. He did clearly state that he knew nothing about the history of the engine as he'd bought it as part of a "job lot" from another breaker who was going in to bankruptcy.
I suspect that a weak mixture, poor oil supply/quality/lack of changing and full throttle caused the granulation of the piston and when finally it was starting to break apart it chapped the valves, but by this time it was so metalurgically compromised the resistance to the steel valves was like putty!
I just wonder how much granular aluminium you will find in the sump and maybe smeared on other working and bearing surfaces?
All the best with it.
Uploaded by Bill
-
Rather you than me Michael. But it's a great project to post up on here (with Bill's help).
I'm no expert on engines by any means but good luck to you.
From my very limited understanding the oil pump will need serious examination too I'd imagine.
I recall Bob Berry's problems with his CBX1000 IIRC in Classic Motorcycle Mechanics , circa the 90's when some blast material got inside and ruined his newly rebuilt engine which again IIRC was being carried out by one of the well known specialists at that time.
I like your philosophical approach! ;)
-
I think I'd be looking at that complete bike assuming you could hear the engine running*. You could probably flog off the rest of it. As has been said, further horrors are likely to emerge with this one.
Re bead blasting: a long time ago I had a Triumph Stag which was a lovely car. It was let down by the state of the cam covers so I whipped them off and put them in to be bead blasted and powder coated. They did look lovely. A few days later the oil pressure gauge was dancing up and down. What I hadn't realised twas that under one of the covers was some steel mesh to act as a sort of breather filter. This had captured the beads which then found their way all over the engine. There were deep grooves in the oil pump and the engine was effectively a write off.
*Oh, just seen it's been sold for £650. There's another for £800 or offers: https://www.ebay.co.uk/itm/306352937578
-
I intend to send as many different photos over to the bloke who I hope will be rebuilding the engine. If he advises me against it then I go to plan B.
Not quite sure what that is yet but I’m sure I can come up with one 😁😉
In the meantime I should be getting the wheels and frame back from the soda blasters in a few days time. That’ll give me something else to focus on. I’ve got to firm a completely new subframe as the original had been cut off. Should keep me out of mischief for a few days.
Ps… I am (if I continue with this engine 🙄) getting the casings, barrel etc vapour blasted Ian. Which obviously only uses water and not any form of medium.
I’ll post up what the “expert” says once he’s had a look at some photos and got back to me 😁🤞
Cheers, Michael
-
Aye Michael, it has been suggested that the head gasket let go, you can see that there is a darkened area to the left of the two valves that are salmon tan in colour. This could be the cause of the weak mixture, high temperatures, etc., leading to the granulation of the piston and its failure. Maybe worth checking those mating surfaces for truth etc?
Best, Bill
-
Having given the grenaded engine a lot of thought and having spoken to the Dave from D&M engineering about it. I’ve decided that I’m “in for a penny, so I’m in for a pound” (probably quite a few in this case🙄)
If I don’t spend the money to get it repaired, who will. Probably no one. So it’ll probably end up scrapped. Yet other R/S engine that ends up going to that Honda scrap yard in the sky.
Plus, no matter I buy, I don’t ultimately know what I’m buying. Even if it’s a runner, the one I’ve bought off Kevin might go pop for all know.
So, I’m going to continue to strip it and get it all over to D&M engineering and let them work their mechanical magic on it 🤞
I’m going to see myself as the custodian of the little RS engine 👍
Cheers, Michael
-
There’s logic in that approach Michael. Once sorted, it stays sorted in your hands. Also, you’re preserving another r/s.
Kev
-
There’s logic in that approach Michael. Once sorted, it stays sorted in your hands. Also, you’re preserving another r/s.
Kev
Thanks for the encouragement Kevin. I kind of feel I need a bit of it at the moment 😁
On the upside, I collected the frame, wheels and assorted brackets from the soda blaster today. So I can now set to and get the subframe made up and welded in place. Oh, that’s once I’ve actually finished stripping the engine down 😏
The list just seems to be growing, day by day. I think this “quick” project will turn into yet another labour of love. HOWEVER, I am determined to get it, at least looking half finished ready for the Stafford show in October 🤞
Cheers, Michael
-
HOWEVER, I am determined to get it, at least looking half finished ready for the Stafford show in October 🤞
Cheers, Michael
😂🚨😂
-
Oh you may mock. You can buy your own jelly babies this year 🤣🤣