Please help identify my bike

[NicoV]

I've wanted a vintage dirtbike for a while now and made a trade the other day so now I'm the proud owner of a Husky 250. The problem is that I can't figure out exactly what model it is.

Here's a pic of it.


It seems to have some parts off a MC 258 (Swedish military bike). The fuel tank and rear fender I'm pretty sure are off one of those, and the exhaust looks to be the same too but that might've been used on other models, it goes round the post. The seller thought it was a MC258 but the frame doesn't match and the engine is a manual, not automatic. From what I've found I think the frame is a 1972 frame but I'm not sure, can't find a frame number on it anywhere.
The engine id is 2033 which comes back to a 1974 250CR, I'm pretty sure the cylinder is not original to the engine because it has 2 extra head studs (or holes for them) whereas the head has just 4 holes. The 74 parts doesn't show the extra holes/studs.


Can anyone help me identify the exact year and model of it?

This thing needs a lot of TLC (piston is stuck in the cylinder amongst others) and I'm gonna need a whole bunch of parts to get it in good shape again. Might as well try and get it back to it's stock configuration while I'm at it

 

[NicoV]

After further investigation I guess the frame could be a 74 too. I can't find the brackets that are just below the upper mounting holes for the rear shocks anywhere though. But someone may have added those, even if they do look stock.

No serial... Nothing on the other side either.


What years/models had these angled rear sprockets? Also note the sides on the rim, same on the front wheel.


The headlight is probably off a MC258, not sure about the front fender, it's shorter than anything I'm finding online. Could just be cut off obviously.


The exhaust, I'm pretty sure it's off an MC258.

 

[NicoV]

Muffler


And the fuel tank, pretty sure this is off a 258 as well. It has some brackets on the inside for the oil mixing pipe but the pipe itself is gone.


Better shot of the engine. This side looks okay-ish but the clutch/kick cover has cracked and has been badly repaired. Does anyone know if a cover from a different year will fit?

 

[visiteur1948]

HUSQVARNA 250 RT

 

[NicoV]

I'm not so sure about a 250 RT, there are a lot of details that don't match. Eg the swing arms on mine are the 74 model.
I think might simply be a 74 Mag 250 with some parts from other models A lot of details match, eg the handlebars, wheels, seat. The front fender might match too if it weren't cut off (I confirmed that it is in fact sawed/cut off).
Other than the front fender all plastic has been replaced, it has the wrong exhaust, and wrong fuel tank.
So that gives me a nice shopping list, gotta get it running first though..

But what puzzles us most is why it has no frame number. Any ideas there?
If one were to order a replacement frame back in the day, would it have a frame number?

 

[jimspac]

It also seems to have 125 or 175 Leleu hubs on it front and rear. The rear wheel at least does not belong on that bike actually the front end is Betor forks that came on the 125 and 175 models as well

The frame number is likely buried under paint; flat band on right side of steering stem just above lower bearing Scrape the paint off the band on both sides of the stem. If the frame was replaced with new it would not not have been stamped

Since the head is off measure the bore size. 250 bore will be around 69mm The cylinder does not seem big enough for a 250 The whole thing might even be a 74 125 or 175 with a MAG swingarm. At any rate Welcome to the Vintage Hodge Podge

 

[NicoV]

Thanks!
The bore is 69.5 so it's definitely a 250, engine id and bore were amongst the first things I checked Actually the first thing I checked was the number of fins on the cylinder which pretty much confirmed it was a 250.

The frame is going to be repainted anyway so I'll try and scrape away some paint. It looks way too flush though, I don't think I'm gonna find anything there. But we'll see!
Would these brackets that are just below the rear shock brackets on the frame be on a 125 or 175? I haven't seen those on any of the pics I've found online no matter what year.


Re: fork, it looks exactly as in the parts manual for the 74 250 so I think it is correct? At least the front has a Leleu hub, haven't checked the rear but I did notice that at least the rear sprocket not correct. The rims do look correct though but then again those were probably also used on the smaller models.

My theory is it was originally a mag as the majority of the parts on it suggests that, but it was ridden hard and replacement parts were taken from other bikes.

 

[jimspac]

The rims are Akront, used on many Euro models back in the day. Akront came out with ridgeless rims due to the popularity of the DID rims that were introduced by the 1973 Honda Elsinores. If there is a serial number on the frame, they were usually faintly stamped.

The brackets you circled were an addon by most likely the 1st or 2nd owner trying to extend the competitive life of the bike by laying down the shocks to increase the rear wheel travel. Very common on many racing bikes in the mid 70's .

The 74 250 MAG had Husqvarna black leg forks and Husqvarna black conical motocross hub.

 

[NicoV]

After scraping some paint I found part of a serial number I can clearly see it says MK there but unfortunately that's where the fun ended because I can't make out anything else with 100% certainty of what it says. I think there might be a 1 after the MK but can't tell if it's part of the serial or just a scratch that I made with the knife I used. Also think I see the lower part of a 3/5/9 there but it's really to faint to be sure.
You weren't kidding when you said it was faintly stamped!

 

[visiteur1948]

 

[NicoV]

Thanks Visiteur. My engine is a 2033. At least the tag on it is clearly readable

 

[NicoV]

 

[jimspac]

How bad is the clutch cover? You may be able to use one from a 72 125 /175 and up as I read the early developement of the MAG and GP 360 engines were built on a 125 case set. You can also check from 250/360 GP and the 76-78 models in general. Your cover may be repairable. I use JB Weld and repair from the inside and out to ensure oil sealing

 

[NicoV]

It's pretty bad really It's cracked in several places and fixed using JB weld or something similar. On the outside.... It looks like crap so if I'm gonna restore this bike I'll have to find a new cover. Thanks for the tips on possible replacements. Will a 75 CR cover fit? It has ribs in the front but it looks like it might fit.

 

[ruwfo]

It's pretty bad really It's cracked in several places and fixed using JB weld or something similar. On the outside.... It looks like crap so if I'm gonna restore this bike I'll have to find a new cover. Thanks for the tips on possible replacements. Will a 75 CR cover fit? It has ribs in the front but it looks like it might fit.

View attachment 28955

Yes, any 75-80 left side cover will fit no matter the model or engine size.. remember kicker & gear shift lever stay on the case, when
removing it usually. That's because rewinding the kick spring if you take the kicker off is a real pain to get right

Husky John

 

[NicoV]

Thanks for the tip

First thing on the todo list is to get the piston unstuck and see how the rest of the engine is. The clutch works and all gears seem to engage so it doesn't look too bad. But I'm a bit worried about the crank because there definitely has been water in the engine. Above the piston it looks pretty good, honing it will probably do. But I don't know how things look below the piston because I haven't gotten it to move yet. Going to fill it with diesel and we'll see if that helps.
Supposedly it was last ridden a 2-3 years ago.

 

[jimspac]

If the piston is low enough, you may be able to turn the flywheel and lift the cylinder off the base gasket enough to remove the wrist pin and pull the cylinder and piston off the engine. The piston that way can be removed from the cylinder without risking damage to the crankshaft

 

[NicoV]

That'd be great but I don't think it's low enough, I will have to check. It's stuck with the piston crown just enough down for both the intake and exhaust ports to be open, the crown is right at the top of the intake slots.
I'm having a bit of trouble keeping it sealed for my diesel bath. Seem to have gotten the intake sealed, I clamped a piece of plastic between the intake flange and the reed cage. Did the same for the exhaust which also seems to be sealed, but diesel is coming out somewhere and I'm not sure where, I can see it dripping off the bottom of the case. Could be leaking at the cylinder base, or maybe a leaky crank seal.
I'm thinking maybe I have to put the cylinder upside down into a bath in order to get the ring area soaked properly.

I also removed the clutch cover and at least underneath that there were no visible problems. The gears and clutch look great. There was a little bit of water in the oil but no rust whatsoever there.

The piston will come out, I've seen much worse. The question is how many (if any) parts I will have to replace afterwards.
These pics are from a 68 Rotax 370 opposed twin.. I actually had to dismantle the engine until I was left with a crank, piston and cylinder stuck to it. We had to get it out with a pneumatic hammer, hoping the cylinder would survive (this engine has the intake on only one of the cylinders and it's hard to find an intake cylinder in usable condition, the 3rd pic explains why). Unfortunately rust had taken its toll on the sleeve and a piece of it came out with the piston. But we did eventually get it out, and the crank was in no worse shape than it was before

 

[ruwfo]

i've used ATF-Acetone mix a "home brew" mix of 50 - 50 automatic transmission fluid and acetone (nail polish remover)
with decent results also Deep Creep by seafoam works great..Just remember if it took 2 years to rust it isn't going to break loose over night, give it some time.
Husky John

 

[jimspac]

Marvel Mystery Oil works well and I think I used that with sporadic shots of PB Blaster. Took about 2 weeks of putting it in 3rd gear and popping the rear wheel in opposing directions to break the rust enough to allow the fluids to do their job. This I did on a 1982 750 Maxim which is an inline 4 cylinder. End result - Saved all 4 pistons, rings, and the cylinders cleaned nicely with a cylinder hone