Suzuki 2 Strokes

Hey guys!
I thought I'd share my recent score on this old enduro I found the other day. I have been looking for a two stroke dirt bike for a couple months now and saw this one up on CL and thought it was a good deal so I jumped on it. All the ad said was that it was a 1979 250cc Suzuki enduro and was running 6 months ago and just needed some carb work. Being that I have acquired a keen interest in Suzuki smokers these days I researched a bit more into what the bike could be since it had no model designation visible or descirbed. The http://www.suzukicycles.org/ website is such a great resource! I determined that it was a PE250 and realized that it was truly a pretty sweet bike so I called up the seller and made a deal. When I brought it home I realized it was not a 79, but had to be a 77 according to Jarmo's site because it has a metal tank (78 and on had plastic tanks) with black decals and the motor and frame numbers were very low numbers.







I got it running in about an hour after getting it home, just cleaned the carb real quick(it was nearly spotless) and got rid of the old premix and poured in some fresh 20:1, checked for spark, kicked it over and started up fine.

Nice bike, very similar to my 1976 RM 250. I like the way Suzuki tucked the expansion camber out of the way from damage. Don't think I have seen a bike strapped in a pickup bed like that before. Aluminum tank? I bet those are getting hard to find.

Yes I believe it is an aluminum tank, it has a few dents, but that's expected of an old enduro

The bike seems to be starting well and I took it for a lap around my block yesterday, man this thing pulls! haha..
There is a knocking sound coming from the engine, particularly noticeable at idle, I am hoping it's just because the plug in the jug right now is one step hotter (NGK B8EV) than the standard (NGK B9EV). Regardless I did a compression test on it just to get a feel for the state of the cylinder and rings, the service manual called for over 100psi and 140psi as a known good reading. I was happy to find that I was sitting right at 140psi and it held for some time.
My other concerns are the intake and exhaust manifolds, they have turned into rotten goo, and should be replaced.
The exhaust is quite awful smelling, I'm not sure if the pipe can get hot enough to burn off all the old oily gunk from however long this bike sat, so I may end up taking it off and trying to figure a way to clean out the inside.
I used the factory recommended 20:1 premix, but was reading on other forums that I can probably switch to 32:1 because of the improvement in modern synthetic 2 stroke oils. With the 20:1 in there right now it definitely smokes quite a bit, I'm gonna try 32:1 on my next batch and keep an eye on the plug to see if this is too lean or just right.
I need to get a new brake lever, then register the bike and get it out in the dirt for my maiden voyage! Fun things to come!

On second thought, I think the knock might have something more to do with not running 95 octane fuel as recommended. Since I can only get 91 at the pump here locally that's what I used for my pre-mix. Next time I find a station that sells higher octane gas I'll try that out and see if it cures the knock.

My 76 RM250 had a knock when I first got it way back in the eighties, I rode it all season and then torn it down to find one of the wrist pin clips missing and a bit of damage to the cylinder wall of coarse. I had it bored out, I can't remember the over size and put in a Wico piston. I put new rings on it once since then. I don't run it much now but try to get it out a few times in the summer. I run 91 octane I believe and I haven't noticed a problem. I have always used Golden Spectrol mix in it at the ratio recommended on the bottle. The noise you are hearing could just be a sloppy piston/cylinder clearance, I wouldn't think it would ping much at idle. My TS 250 makes a little noise at idle but I assume it has quite a bit of wear as it had a hard life before I got it, it runs fine and I haven't felt the need to tear it down yet. I bet your PE would give my TS a good run for the money on the road!

Yeah that could be true, however it only has just over 3000 miles on the clock and it had tons of compression, I think if it had sloppy piston/cylinder clearance my test would have yielded lower values, but can't know for sure I guess without opening up the top end. I'm gonna leave it how it is for now and just have some fun with it.

Mat wrote:Nice bike, very similar to my 1976 RM 250. I like the way Suzuki tucked the expansion camber out of the way from damage. Don't think I have seen a bike strapped in a pickup bed like that before. Aluminum tank? I bet those are getting hard to find.

No I don't believe I've seen a bike strapped like that myself !
in fact we'd get a ticket for that in my part of the World !!

Cheers,
Roger

Suzuki GT750A

GT750Battleship wrote:

Mat wrote:Nice bike, very similar to my 1976 RM 250. I like the way Suzuki tucked the expansion camber out of the way from damage. Don't think I have seen a bike strapped in a pickup bed like that before. Aluminum tank? I bet those are getting hard to find.

No I don't believe I've seen a bike strapped like that myself !
in fact we'd get a ticket for that in my part of the World !!

Cheers,
Roger

Suzuki GT750A

Haha, so much flack for my tie downs! It was very secure and safe, I had it ratcheted down tight and it wasn't going anywhere

I had one of those back in the day, it was a nice old bike. It will smoke a TS250, had one of those too. If you change to 32/1 you will have to mess with the jetting because it will run richer since the fuel has more gas and less oil. It's worth restoring it, I think reproduction number plates and fenders are out there and the aluminum tank can be painted.

This bike is serious fun.