Suzuki 2 Strokes

Hey all,
I'm from Sydney, Australia. This is my first post on the forum but i'm sure it will be the first of many.

I recently acquired a pretty weathered and forgotten GT185. This bike is my first 2 stroke and although I would of preferred a larger capacity GT this one happened to be in my price range.

Despite rotten tires, some rust spots and the numerous redback's lurking around the bike seems in decent enough condition. I purchased it without a key but managed to use the key from my CX500 to turn the ignition, I connected a fresh battery and all electrics are working fine. This weekend I'll be running the carbs through the ultrasonic cleaner, dumping and replacing the oil and attempting to start it.

This bike has done a little over 50,000 k's and from what I gather it's almost definitely going to require a top end rebuild and possibly also bottom end. My experience in working on bikes only extends as far as valve jobs and cam chain replacement however if this motor does require an overhaul I would like to learn to do it myself.

I have a few questions and thought this would be the best place to ask.

What is usually replaced in a bottom/top end rebuild of these motors? I want to start creating a list of the parts required and calculating a budget for the rebuild.

I have read a thread on this forum about parts for the 550 from other models that will fit and are cheaper/easier to find, is anyone aware of similar parts for the 185?

Money is pretty tight for me at the moment, without labour roughly how much can i expect to sink into a top/bottom end rebuild on this motor?

I have searched everywhere trying to find documentation of someone who has rebuilt one of these motors, besides a top end job on youtube i've had no luck. Is there any threads on the forum you are aware of that details a rebuild like this?

Any help would be much appreciated.

Thanks,
Jarrad

Hi,I'm in Sydney also..so I "know" what "red backs" are.. I have no experience with the small capacity GT's,generally a top end rebuild is pistons,rings,little end bearings etc.Depending how much wear has taken place with the bores,a light hone might be all that you need to do,IF the bike has been sitting around for years on end,you may find that the crank seals have gone hard,& this will cause a dramatic loss of compression,two strokes rely on being air tight to operate...!
A major rebuild on my GT750A 5 years ago was around $3,000 !!
a lot more involved of cause,than your GT185....!
You can try to source parts locally first...I'm surprised how much is still available for my GT750 from Suzuki Australia,but I do get a lot of stuff from Europe & the USA,so a bit of Internet "surfing" can be helpful,,? There are a few other Ozzies on this forum,welcome aboard.PS If you require the details of the Guy who did my motor for a quote,you can send me a PM
Cheers,
GT750Battleship.

Hi Jarrad, welcome to the board. From the picture, looks like a good starting point for a project. I've never put a hand on a GT185, but it should be basically the same as rebuilding my T500, so I'll give you a quick overview. It is a pretty simply engine (no valves to adjust or cam chain to replace). I don't know how much you know of 2 stroke engines, so forgive me if I tell you stuff you already know.

Top end: Base and Head Gaskets, Rings, Piston Bearings, Circlips, and Piston Pins (not 100% necessary, but best to do if any wear), Exhaust Pipe Gaskets. Once apart, check cylinder walls for condition. If scored, worn (out of round, or diameter is on the high end of spec), you'll want to have them bored and oversize pistons installed. On my T500, I just honed the cylinders, and put the standard sized pistons in. Regretting that now, as large clearances cause piston slap. This winter, I'll be tearing it down again, and redoing the top end with oversize pistons.

Bottom end: Rebuilt Crankshaft and all case seals/gaskets. The bottom end is really simple to do, as generally you end up installing the crankshaft as an assembly. The crankshaft on these Suzuki 2 strokes are a pressed together assembly, and most folks don't have the necessary tools (presses, measurement gauges/jigs) to make it worthwhile to take the project on. So it gets sent off to someone who specializes in rebuilding 2 stroke crankshafts. With a rebuilt crankshaft in hand, it is really just drop the crankshaft into your (cleaned) bottom case, reassemble with new case seals and sealant, and bolt it back together. (Well, almost that simple).

Crankshaft: Evaluating the current condition of the crankshaft is key. All bearings (mains and large crank ends) should be smooth and without side play (within tolerances). 2 stroke crankshafts also have seals, which should not leak. Unlike 4 strokes, the crankcase under a 2 stroke engine's piston doesn't have an oil reservoir - it is dry, and used to compress the next fuel/air charge going to the cylinder. If the seal leaks, it will allow air to lean the mixture (very bad) or suck oil from the transmission (just bad). You can perform a pressure test (search this site, or the Internet) before you tear down the motor, or just replace the seals preemptively when having the crankshaft rebuilt (this is what I did).

I do not know the availability of parts for the GT185. For the T500, the main bearings and connecting rods are NLA (no longer available), as well as at least one of the seals (but still can be found). If the crankshaft is a viable candidate for rebuild, typically it is just sending off the crankshaft, the 4 seals, and a check, to an experienced 2 stroke crankshaft rebuilder. No idea who does this work near you, but there are folks here who can probably recommend someone.

Good luck with the project, and again, welcome to the forum.

Thanks guys for your helpful replies.

Since the first post I have started the bike, it actually started second kick which I was quite impressed with. However, it is smoking pretty heavily. At least I know it's a runner now though.

I am going to pull it down over the comings weeks and examine the internals. I'm thinking that with 50,000k's on the clock I'm probably going to have to do the bottom end as well.
I found a bloke here in Australia that will rebuild a pressed crank for $90 if all parts are supplied. I've managed to find a rod set with bearings included and many of the other parts required on eBay for not too much $$$.

I'll keep is thread updated as I go along.

PS. The fork tubes on the bike are in terrible condition, probably the most rusted component on the bike, I've searched online for some replacements but with no luck. Does anyone have any for sale?

Thanks

Hi, I had a pal with a 74 GT185 back in the day - lovely bike!
On fork tubes, here in UK many folk send them up to Philpots to have them ground back, straightened if needed, hard chromed, and ground back to perfect size, and the cost is less than half NOS price, IF you can get them. I have had two sets done by them and very happy with the work. I have no clue if there's an Aus company that does that work?
Cheers,
Mike

well if money is tight I can always help you along by selling me that rack!

Haha actually johnakay I had planned on selling the fairing, crash bars and rack on eBay as I won't need them.

I'm in AU though so might not be worth it for you in shipping if you are serious.

Thanks for the tip on the rechroming yeadon, I found a place in Sydney that does it so I will get a quote today.

On another note, pulled the heads off quickly last night. Looks like their is a bit of movement on the pistons so it's probably a good thing I'm tearing it down. I was watching a video on youtube of a guy who said he had bored out his 185 to 200. Would that increase yield much extra HP? I figure if I have to re-bore anyway maybe I should go larger.

Thanks

Does that plater offer "hard chrome" or "decorative/show chrome"? It has to be a hard chrome finish and the fork legs need to be ground before plating and finished off on a centerless grinder.

Yeah these guys were recommended for the service. If anyone in Sydney requires the service this company is called A1 Hard Chrome.

Hey tz375 I just realised from reading another thread that the video i've been repeatedly watching on youtube is actually of your GT185. Nice bike.

I also read that you were looking at some performance improvements along with the chambers, did you ever end up working anything out there? While I am tearing the bike down I'd like to make any improvements I can.

Which video is that? Unfortunately I don't have a 185. I have seen one and raced against another, and have a mate who's building one to race and he's aiming to get around 40hp out of it, but that's as close as I got to one.

Ah that's embarrassing, it was actually vintageman this is the bike i'm talking about http://www.youtube.com/watch?v=NJSIxujKfzk" onclick="window.open(this.href);return false;