'69 CB250 Tracker

So this is the starting point....


and here's the engine...


and here...


I can design. I can fab basic stuff. I have friends who can weld and friends who can paint. What I CAN'T do is put an engine back together with any degree of confidence. What I DON'T have is a mechanic friend. Who can spot the problem in this scenario?
Little help here fellas?

I'm reorganising the bedroom to get a workbench in. I'm a single dad so when the munchkin has gone to sleep I can give a couple of hours a night to this. But where to start and how? These are my issues right now...

What I want to end up with is a very clean but fairly basic tracker style looking bike. So.... lets go!!!

I can't be much help but I can sympathise. The amount of times I have found myself neck deep in the proverbial with no clue where to even start, yet somehow I've been working on the same bike for 3 months.

Ill be watching!

That looks like a 70s CB360. I dont think Honda made a 69 CB250. Either way it looks like a fun project. There are a million + 360 motors out there. An easier place to start would be to find a complete motor still together and use that motor in the bike. Then learn on the motor you have now and build it up. I always like to have a spare motor for my bike. Anyways, just a thought. Good luck with the project and enjoy the process. ;D

CB250 switched to left side drive and a full frame in 1968 or so via a quick google search. I know the older versions were a stressed member frame and right side drive chain...

You can get a print or online manual for that later series of 250 pretty easily. It's not as complicated as it looks, just take your time, be patient... kind of like riding it when it is all back in order, it IS a 250 after all...

Parts are pretty easy to get as well, even the dealership can still get some stuff in. http://www.cmsnl.com/honda_model8286/ is probably the closest you'll find to "one stop shopping" for it.

Happy tinkering!

Sunnamp, it's definitely 250. Chassis # CB250 6017892. Engine # CB250E 6022256. Anyone know of a site where you can plug in your numbers and it tells you the year built?
Scruffy, I've used CMS before for carb rebuilds and stuff. Just never rebuilt an engine. Kind of exciting, kind of scary. One friend just said, go for it. You'll get 80% without help and use professionals for the rest. sounds like a plan to me. I will look for the online manual though. Thanks!

Wizzer said:

Sunnamp, it's definitely 250. Chassis # CB250 6017892. Engine # CB250E 6022256. Anyone know of a site where you can plug in your numbers and it tells you the year built?
Scruffy, I've used CMS before for carb rebuilds and stuff. Just never rebuilt an engine. Kind of exciting, kind of scary. One friend just said, go for it. You'll get 80% without help and use professionals for the rest. sounds like a plan to me. I will look for the online manual though. Thanks!

Click to expand...

Does the frame have a compliance plate? The date should be stamped on it

No compliance plate. I don't think they were necessary in Australia until '71

that might be a cb250 but it's different from the earlier cb250/350's which have bolt on passenger footpegs and don't have those slots in the gearshift cover or the threading on the cam for the tacho or whatever it is. those parts all look like cb360 parts. here's a cb360 http://en.wikipedia.org/wiki/File:1976_CB_360.jpg
i think what you have is a http://en.wikipedia.org/wiki/Honda_CB250_G5
i have an australian delivered 1970 cb350 which theoretically shouldl look exactly the same as your bike except for engine capacity, and i can tell you there's a lot of differences,

Your bike is a 1972 CB250K2.

I ran the engine number and the chassis number here: http://www.hondascooterspares.co.uk/Spares/vinList.asp

I'd start by cleaning parts one at a time and then bag them by page in the parts book. That way you get to identify the parts and you also find out what's missing. Then I'd inspect the parts that are likely to wear out like cams and rockers against the specs in the Factory Service Manual.

Then I'd lap the valves and start assembly, one step at a time. Look on line for pictures of motors like yours opened up for clues as to what goes where. Your 250 is the small brother of the Cb360 and many parts will be common to both.

When you are cleaning single pieces of metal, degreaser and water are fine but dry them and spray some WD40 and then bag them. Do not do that to the gear clusters or the crank. You will want a baking tray or washing up bowl to put those in and wash them in WD40 with a stiff 1" paint brush to get them clean. Oil any beraings after cleaning them and spin them until they sound clean. Once you do it, it will be obvious.

Good luck and take your time.

Liam, I have a '71 350 for my next project. The head is very pitted inside and parts are hard to find so I picked this up instead while I find the right bits. I think you're right about the G5. Scruffy, your site says K2 but a Google image search indicates otherwise. The gear cover, the tubular frame behind the tank rather than pressed.
Thanks guys. Nice pick up before I started ordering stuff that wasn't right.
teazer, that's exactly what I'll do. Having never done it before I was feeling a little overwhelmed looking at all those pieces of the jigsaw and that's exactly the direction and advice I needed to nudge me along. Thanks!!

Does that mean I have a 6 speed box??? How to tell?? And can I fit 360 pistons in? It looks like a lot of meat in the sleeves there and the same size gudgeon. Excitement just crept up a notch or 7

OK, the guys who know what they are doing tell me taking it out too much will warp the sleeves. Makes sense. But there is a lot of sleeve there. I want to take it bigger. More top end!!! Anyone know of a usable piston bigger than the standard 56mm with a 16mm wrist pin?
I've cleared a space in my bedroom to fit a workbench. Now I can start sorting this engine out and put it back together.





The manual is downloaded and I've found a good site with exploded veiw of the engine. I can now work on it at night when the munchkin is in bed

For great exploded views of any engine, check www.cmsnl.com

Good luck!

That's what I'm using. However I'm rapidly realising that I will need some experienced help when it comes to the fiddly bits. Some many little plugs and spacers and springs and gears. All similar looking.
All the major pieces and a lot of the minor pieces can be traced to their source. But the little bits.... So many. I'll see how far I can get in my own