Gt185 Crank Seals

General discussion about Street two-stroke Suzuki motorcycles.

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Justinf74
Still in the Driveway
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Joined: Sun Nov 17, 2019 6:12 pm
Country: U.S.
Suzuki 2-Strokes: GT185

Gt185 Crank Seals

Post by Justinf74 »

I’m new to this forum and just picked up a 73 GT185. It hasn’t ran in years and needless to say, both cylinders were low on compression. I was hoping the rings were stuck but they weren’t. Now I’m on to crank seals. This is the first engine tear down for me. Any tips or tricks to make this easier on me is much appreciated. Thanks
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jabcb
Moto GP
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Suzuki 2-Strokes: 69 T350 thru 75 GT750
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Re: Gt185 Crank Seals

Post by jabcb »

An introduction + pics would be appreciated. (You can’t upload pics to this website. Use a photo website like Flickr & post links here.)

Crank seals is a task best left to the pros.
Bill Bune is a specialist shop that does lots of two stroke cranks. Highly recommended: http://www.billbune.com/index.html

Do you plan on doing all of the other motor work?
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Craig380
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Re: Gt185 Crank Seals

Post by Craig380 »

Hi and welcome. Sounds like you'll need to rebore the cylinders, failing crank seals will not cause low cranking compression in the cylinders.

I wouldn't automatically assume the crank seals have failed. For what it's worth, I'd pull the cylinders and pistons and inspect the crank through the crankcase mouths. If it seems OK, mix up some 2-stroke oil and fuel in a 50/50 mix and pour it into the cases and let it sit for a few days, then drain it out. This can refresh the seals a little and lubes the crank bearings too.
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
dollydog
Yeah Man, the Interstate
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Suzuki 2-Strokes: several gt250 ramairs

Re: Gt185 Crank Seals

Post by dollydog »

i've done the same trick, craig, except i've always used diesel or parafin in the crankcases - they don't evaporate as quick. 185's are a pretty easy engine to work on, the only bit i hate about them is the ridiculous gearchange mech on the left side. sure suzuki could have come up with something better than that :D
cheers, dd.
p.s. if you want to upload photo's, then postimage is dead easy to use and free.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
Justinf74
Still in the Driveway
Posts: 3
Joined: Sun Nov 17, 2019 6:12 pm
Country: U.S.
Suzuki 2-Strokes: GT185

Re: Gt185 Crank Seals

Post by Justinf74 »

I haven’t been able to post on this thread all day. I’ve typed out this reply and it keeps sending me to an error page :evil: the crank does spin freely and smoothly. I’m pretty positive the cranks bearings are good. I’m going to try what you guys have suggested and we shall see. Otherwise I’m going to have the cylinders checked and order some new pistons and rings, reassemble and see how she does. Thanks again for the replies
Justinf74
Still in the Driveway
Posts: 3
Joined: Sun Nov 17, 2019 6:12 pm
Country: U.S.
Suzuki 2-Strokes: GT185

Re: Gt185 Crank Seals

Post by Justinf74 »

And I’ll try and get some decent pictures up tmrw. A little background on me is I’ve been into motorcycles for years, I’m 35 but have had an it using from sport bikes to harleys. I’ve always a loved two strokes and love the older bikes styling. I’m not a mechanic by no means, but have a pretty good clue, enough to get me in trouble at least lol.
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