1981 GS250 Rebuild Project

[philo]

Just wanted to update...I tested the bike fully over the weekend and other than a minor problem with the front brake to tail light switch (at the brake lever with the tiny spring) that has since been fixed it rode great. Everything worked perfectly; no drips, great charging, etc. Top speed of about 90 on flat roads. My brother rode it while I rode behind to gauge his speed (speedo ends at 85). I had it trailed at 96 MPH on a light downhill section, which was around 9500 RPM according to him. The max HP is achieved at 10k but with the 15 T engine sprocket it needs a slight decline to fully use it. It moves surprisingly fast but you have to keep that engine wound-up because it feels a little sluggish below about 7k RPM. Really, I think 300cc matches the current setup of the bike more than 250 but that is another consideration for when I finally get to the top-end rebuilt, assuming that kind of change can even be made. For now it still needs a front brake rebuild so that's next; stopping is terrible considering the speed. I'll post again when I finish that, which may be a couple of weeks. For now I need to ride! Thanks again for all the help.

 

[Guest]

Awesome stuff Phil, glad to hear it!

 

[philo]

Picked this 1980 GSX250E up for $50. Missing the headlight, front brake and fuel petcock but otherwise in good condition. Engine was also stuck. 4,800 on the odometer. Had been sitting over 10 years and it showed, BUT the bike looks like a bike that was well taken care of before it sat so I have my hopes up.

So far engine came unstuck with relative ease with some penetrating oil into the cylinders and some rear wheel shaking. Waiting for some carb seals, spark plugs, and an oil filter so I can start/test the engine and work the corrosion off of it (50 miles or so from what I read before another oil/filter change?). Carbs are off right now; I'll probably strip and dip it soon while I wait for the o-rings but it was 111 degrees yesterday so I am in no rush.

 

[Guest]

$50? Bargain! Nice score

That looks pretty much the same as the one Mike-S built up as a sort of motard style with long travel suspension etc.

Here's the thread:

http://www.thegsresources.com/_forum/showthread.php?t=175721

Good luck and keep us up to date!

 

[philo]

Nice thread, fun to read and (IMO) an awesome idea for a 250.

A few interesting notes about the GSX250...

It was not sold in the US in '80/81 and is VERY different looking than the '82 GSX250 (though quote similar in engineering), the closest year I could find to it for parts (thanks Pete for that). However, I did find that the GSX250 is somewhat of a hybrid between the GS250 and GS450 from '80/81. So here is a quick summary of the similarities...

GS250
Engine (8 valve, though without the X, strange I know)
Frame (added a tank mount for the GS250 frame)
Fork (Looks the same, not 100% sure though)
Carbs (Mikuni BS30)
Brakes

GS450
Wheels (18" aluminum alloy; GS250 uses 17" R and steel rim/spokes)
Tank & Panels (more sporty looking)
Seat

Probably more similarities but that gives the basic idea. The performance of a GS250 with the look of a GS450; though, a lot of weight was dropped from the GS to the GSX and the engine sprocket was geared one 1T less to help adjust for the larger rear wheel. All-in-all should be a fun bike to ride. My brother rides the GS250 around town when we ride and I have been stuck on my FZ6R (my long distance commuter bike) so the GSX250 has me really excited! Watching him take-off on that GS250 in a wheelie @10k RPM does bring a smile, though...watching a 250 race 1500cc+ harleys (I know, it's a Harley, but still) is so funny, makes me want to join in

Most recently I rebuilt the starter button and starter motor and re-wired most of the corroded grounds. Everything else tested correctly on the mm and when I finished I was getting spark from the plugs and the engine was turning over. I ordered a new petcock and some A&H super washing soda to clean the tank out. I also did a full dip and rebuild of the carbs with the extra set of o-rings from the GS250 carbs so the bike should be good for a 50 mile test burn. Still needs tires, headlight, battery and front brake (thanks for that mikesxs link, going to get a new mc there). Also a lot of cleaning still remaining but I was able to get some of the plastics re-dyed while I had everything off for wiring. I'll post again in another week of two once I get it riding, and a new updated picture. Thanks again for all the help.

 

[Guest]

Thanks for the update Phil, very interesting! And yes, that definitely sounds like a 250 in 450 clothing

Wheelie on the 250 at 10K RPM hey? I've never voluntarily wheelied my 450... maybe I should try that some day... maybe... haha

Sounding like the GSX is gonna be some fun for sure!

 

[philo]

Petcock arrived and after some time it started up. Ran it for a few hours at low rpm's on the center-stand with a couple of large ind. fans keeping it cool. Going to give it another oil/filter change now and some tires so I can log some miles locally and see how it shifts/rides, but the engine sounded really strong. Still has a way to go. Here is an updated photo...