Suzuki 2 Strokes

Hi I'm new to the forum and im looking at a 76 GT550 that is for sale locally. The bike is in real nice shape but is there any way I can tell if the crank seals are bad before I hand over the cash? I heard it run last week and it idled fine but there was still snow on the ground so I couldn't ride it. Any help would be appreciated.

Mike

Tell the seller, you have concerns. Let him know, for that very reason if he would please allow you to remove the plugs to take a look. When you do, compare them. If one looks noticeably leaner than the others that's a sign. Don't ask him that, until you arrive to avoid him switching the plugs. Also look around areas of the oil pump. Motor oil in the area behind the pump and on engine side cover by the kicker and exhaust would also be a sign. That's about it, unless a compression test is performed. The plugs are an accurate way of knowing, if all 3 carbs have the same exact settings and are jetted exactly the same. Also assuming all jets are clean. I wouldn't buy a 2 stroke, without comparing the plugs first. I can't see anyone having a problem, allowing someone a few minutes to remove the plugs. Exhaust pipes, smoking less than others are also a sign. However, several things can also cause that and it's nothing to be over alarmed about for that reason. But, a combination of that and a lean plug reading on the same cylinder is something to be weary of.

Hi,be aware of the good looking ones ? shiny bikes ,could be masking a real problem ! You really need to hear it running & to ride it,if it's had any recent work,ask for receipts,if possible take someone with you that knows something about the model you're looking at,don't buy the first bike you look at ! ask questions in regard to previous owners & why it's for sale ? petrol tank internal rust can be a problem, it's a "two stroke" you're looking at, so if it hasn't been ridden in years rather than a few months,the crankshaft seals could be suspect...requiring a crankshaft rebuild..expensive ! Excessive smoke once warm while riding could indicate a crank seal problem or it has a leaking oil line valve,allowing oil to enter the crankcase even when standing,(I have a mate with a GT550,his bike has this problem) If you're used to riding modern bikes,be prepared for period braking & handling !!! Go on the Web & have a look at Suzuki GT550 Field Guide this will explain a lot of information on the bikes & the differences between the various models,very good reading.

Cheers,
Roger

Thanks for the quick reply. Are the plugs easy to get at or do you have to pull the tank? I've been looking around on the site about replacing the crank seals and it's something I would probably do next winter anyway. I don't think I would have any problem tearing the engine down and removing the crank. I would actually be looking forward to doing it. I will will take your advise on the plugs.

Roger, it is shiny but but it does look well taken care of. The owner said he rode it all last year. He has a couple of projects going in a very small garage and said he wants to make room for another. I guess it's always a gamble. Just how expensive is a rebuild of the crank?

Hi,I've got the 750 so you costs would be considerably less,I should think..if you pull it apart yourself & taking the crankshaft to the repairer !
my crank was a mess..2 mains/rods cracked piston,third gear was not so good !
Motor bored out to first oversize,Wiseco Pistons/rods used...all up around $3,400 Aussie dollars back in 2008,but will last me a long time Sounds like the seller is quite genuine,being busy with other projects,regular use is a big bonus with these bikes,good luck & I hope you enjoy her,if you buy

Cheers,
Roger

GT550 Field Guide? I didn't know there was one. Link?
The plugs are easy to get at. On the center, drop the socket on first, then attach the ratchet to the socket. I use a 3/8 breaker bar because the 'head' is much smaller than a ratchet.
Touch the header pipes to make sure it's running on all 3. A common problem (not really a problem) is it wants to run 2 at idle, but quickly picks up the third as the RPM's increase.

Hi Coyote,oldjapanesebikes (Ian Sandy) who is a member here posted the info a while back
If you Goggle GT550 Field Guide you'll find it...excellent work by Ian,as is the GT750 Field Guide
Cheers,
Roger

If you do buy the bike, don't just assume the crank needs doing.
Run it and you may be pleasantly surprised.

Don't do it because you think it 'might' be a good idea. Most cranks on running bikes are OK.
If it ain't broke - don't try and fix it - it might make it worse.
Do a search on here for 'GT550' - lots of help and advice.

Main thing to remember is that they are a 40 year old bike and 45 year old design.
'Modern' handling/brakes/lighting were something quite different then.

Field guide to the 550 here (clicky)

I think I'm going to take the plunge. I realize it's an older bike and design. I was 16 when it came out in 76. There was a Suzuki dealer two miles from my house so my friends and I were always there drooling over the 380's and 550's. A lot of the guys in high school had the Kawi triples but I always liked the Suzukis. Probably because I was riding their dirt bikes since I was 11. I broke my wrist at work in November and I won't be able to ride motocross for the foreseeable future if ever again. This will be the first street bike I've had since I was 20 except for a few months on a Harley about 10 years ago. Not sure if I will be able to ride it for a while but it will give me something to look forward to and work on in the meantime

Mike.

Good man.
The GT550 actually came out in 1972, (J model), I had one then - bought it as a 21st birthday present for myself. Lovely bike. I now have a K (running) an A in resto, another K, a J and a bitsa which is a spares bike as well as loads of other 550 related bits.
I always did (and still do) prefer the 550 to all the other triples, Suzy or Kawa.
Less frantic, better handling, easier maintenance and more refined.

Alan H wrote:Good man.
The GT550 actually came out in 1972, (J model), I had one then - bought it as a 21st birthday present for myself. Lovely bike. I now have a K (running) an A in resto, another K, a J and a bitsa which is a spares bike as well as loads of other 550 related bits.
I always did (and still do) prefer the 550 to all the other triples, Suzy or Kawa.
Less frantic, better handling, easier maintenance and more refined.

Right they came out in 1972. I was referring to the 76 that I'm looking at coming out when I was 16. Always wanted one. I also always want a 72 TS185. I got a new TC 125J Blazer in 72. It was $425 brand new.

Mike546 wrote:Thanks for the quick reply. Are the plugs easy to get at or do you have to pull the tank? I've been looking around on the site about replacing the crank seals and it's something I would probably do next winter anyway. I don't think I would have any problem tearing the engine down and removing the crank. I would actually be looking forward to doing it. I will will take your advise on the plugs.

Roger, it is shiny but but it does look well taken care of. The owner said he rode it all last year. He has a couple of projects going in a very small garage and said he wants to make room for another. I guess it's always a gamble. Just how expensive is a rebuild of the crank?

You have the right attitude and outlook in reference to crank seals and buying an old 2 stroke. Another thing you can do, when the bike is idling. Stick the palm of your hand directly behind the top of the pump. There is a breather located there. If the seals are bad, you will get mists of motor oil on your hands. The truth is, a large portion of these bikes, still have the original crank seals. That alone, makes the purchase somewhat risky. Unless, someone can provide proof that the seals have been replaced. But, as mentioned earlier. If the bike has been ridden consistent enough over the past few years. Chances are the seals will be o.k. for a little while. I bought a 750 a couple years ago and the seals were fine the first several hundred miles. Then they simply split apart, due to 40 year old rubber and me riding the bike often enough. It's a gamble. But, if you have the attitude and understanding of these things when buying it helps to soften the blow mentally when and if it happens. The 550's motor is a lot easier to tear down due to it's size and cylinders. Compared to the 750. It's a real challenge just to get the cylinders removed on a 750. Like Allan H mentioned. I also agree that the 550 is a better all around bike. Compared to the 750. You'll absolutely love it. Understand, that sellers say a lot things that aren't quite truthful. That's why you have to investigate.

pearljam724 wrote:Understand, that sellers say a lot things that aren't quite truthful.

No!!??!! Say it isn't true!

Some sellers can be like Lawyers..& Politicians...you can trust/believe me !!!
Regards,
Roger

A pal of mine who has owned very few cars (and only one bike) told me once that, as he knows nothing of machinery, he based 90% of the decision (whether to buy or not) on his assessment of the seller. If he doesn't trust what they are saying, he walks. He's a wise chap and hasn't bought a bad vehicle yet.
Me, I have sometimes bought with my eyes and ears and ignored the other 'tells' from the seller - and regretted it a number of times, showing I don't know as much as I thought I did
Mike