1976 Suzuki GT380 Cafe Project

[jch82]

Hello everyone,

I got the bike from a dude in Cincinnati for $250. His story was that he bought it and was going to get it running and then ride it... He says that when trying to kickstart it, it felt like it was kicking over harder than it should. The final kick he said resulted in "it locking up". His thinking was something in the transmission locked. Well, me not really caring where the issue was, hauled the bike home and started tearing into it. I mean for that kind of money, the motor could be junk and it still wouldn't have been a bad find. My goal is to tear it down to the frame, clean it up, eliminate all the unnecessary stuff, and turn it into a cafe bike. Sorry I don't have a "before" picture of the bike, I was a bit quick to start taking everything apart. Here is where I'm at so far...

Disclaimer: If you can't find your way out of the garage, it's your own fault! ;D

When I got around to tearing down the engine, I found this! Poor little 2 stroke...

My question... Is it possible this happened from the guy trying to kick it over?? I also found a spun crank bearing on the other side of the crank. The middle piston has a bit of scoring on it, but otherwise everything else seems to be in pretty good shape. No issues it seems with the transmission bits either...

Thanks for looking!
Josh

 

[Mad Ratter]

Nice find! will be a good project.
I'm no mechanic, but I reckon he left the fuel on over a long period, the cylinders filled with fuel and tryin to kick it over, it "hydrolocked" ?? could be a possibility.
Just a theory looking at that bent con-rod. Still, at least you know more now you have it apart. Good luck and keep posting

 

[kieferocks]

Nice find! will be a good project.
I'm no mechanic, but I reckon he left the fuel on over a long period, the cylinders filled with fuel and tryin to kick it over, it "hydrolocked" ?? could be a possibility.
Just a theory looking at that bent con-rod. Still, at least you know more now you have it apart. Good luck and keep posting

Pretty sure hydrolocking a 2 stroke with fuel is 99% impossible. The layout of the ports would make it very unlikely. I imagine it was just a weak conrod and finally gave up, but that sure is a strange bend...

 

[bradj]

Good deal man you will be a better person at the end of this motor build

 

[650hardtail]

2 strokes hydro lock all the time...oil leaking thru check valves ( injector llines ) thru years of sitting or by carbs flooding and filling crankcase w gas..

 

[teazer]

+1.

I can show you a few broken and bent con rods from fuel leaking past the float valves. In one case the rider came in to the pits complaining of alack of power. I whipped off the fairing to find big end rollers in the belly pan.

Turns out the rod had bent enough to run on the flywheels when he started it after it flooded. The rub caused it to get hot and when it broke, it punched a hole in the crankcase and parts of the rod and bearing cage went out through the hole.

So. Yes they hydrolock and bend rods.

 

[jch82]

Thanks guys, good to know the guy was probably being honest with me at least! This is my first go at all the engine work, but I have the means and some mechanical knowledge so it should turn out good in the end. I'm pretty stoked to do some metal and fiberglass work though as that is a bit more up my alley!

Josh

 

[Erskine]

Subscribed

 

[interceptor]

I'll be following this one, these are great bikes. I have a 73 GT380 and love it. If you are looking for any parts, let me know, I still have a bunch laying around.

 

[jch82]

I'll be following this one, these are great bikes. I have a 73 GT380 and love it. If you are looking for any parts, let me know, I still have a bunch laying around.

There are a couple things I have been looking to pick up for a decent price...

Ignition Cover - mine has bad road rash and is rubbed through on the bottom side
Crank Assembly - to piece together the good bits on mine with the good bits on another one
Engine Case - several broken bolts and chunk of front motor mount is broke
Small Cover - the little one covers the oil pump
Center Cylinder Head (with or without piston) - one thread for exhaust manifold is drilled and busted up, plus some scoring on the cylinder wall and piston

I did find quite a few things on Ebay, just wondering if there are any other options out there.

Josh

 

[jch82]

I have seen the Clubman bars and also another guy on here that put clip-ons on the forks. I like the clip-on option, but what are my options for a different triple tree? Anything out there already fabbed up?

I would love to get rid of the handlebar stantions if I go the clip-on route. At this point, I am shooting for minimalist and not having any gauges, relocating the ignition (maybe just a hidden switch? no key), adding a toggle switch to the headlight housing for lighting, etc. Basically eliminating everything on the bars except for the essentials... clutch. brake. throttle.

Josh

 

[teazer]

Josh, you probably need a speedo in your state and the whole concept behind cafe racers is an old style road racer look, so it needs a big tacho dominating the front view. There are lots of electronic and mechanical options including your local bike store (or Wally world) for a tiny speedo

 

[jch82]

Josh, you probably need a speedo in your state and the whole concept behind cafe racers is an old style road racer look, so it needs a big tacho dominating the front view. There are lots of electronic and mechanical options including your local bike store (or Wally world) for a tiny speedo

Thanks for the insight, I do know for sure that the stock gauges will never make it back onto my bike...

Josh

 

[interceptor]

I have a couple of parts you are looking for. The covers I'm pretty sure I have, but not an extra cylinder or crank assm. Let me find them and I'll take some pics for you. Also have some clip ons (I'll make sure they fit first) if you are interested

 

[jch82]

I have a couple of parts you are looking for. The covers I'm pretty sure I have, but not an extra cylinder or crank assm. Let me find them and I'll take some pics for you. Also have some clip ons (I'll make sure they fit first) if you are interested

Sounds good, let me know. Thanks!

 

[gk45011]

I'm in Cincinnati as well. I'm subscribed. should be a great looking scoot when your done.

 

[jch82]

I'm in Cincinnati as well. I'm subscribed. should be a great looking scoot when your done.

Going to be a bit of a long build, but I have a few other rideable bikes to occupy my time on the street. Have you ever stopped down to The Comet on Tuesday for bike night? I have been down a few times with a buddy of mine. It's usually a pretty good time down there and always a nice mix of old and new bikes.

I have my bike tore down to the frame right now and I am working on cleaning up welds and getting the rear hoop welded in place. I have cut the passenger mounts off and plan to weld on some steel tubing in roughly the same place to continue the tube frame look for some rear sets. I need to get a engine case (mine has a broken mount) and crankshaft (got a bent rod) so I can get the engine put back together and mounted back on the frame. That way I will be able to fab up the tubing to get the rear sets in a good location and figure out how to mount some linkage rods to make the shifter and rear brake function properly with the rear sets. I guess I could have just used the stock passenger peg location for the rear sets, but I really wanted to keep the open tubular frame and the stock mounts were ugly sheet metal...

Josh

 

[jch82]

Thinkin' I may veer away from the cafe tail section on this one. Here is a potential mock up of the seat pan. I may leave the seat squared off at the back to match up a bit with the rear of the tank. The other thought I had was to round it off with a piece of metal and flare it up a bit.

On the rear, I would weld a cap on the open frame rail and then install some bullet style blinkers and run a 6" LED strip on the square brace I welded under the seat for the tail/brake light.

Here were a few inspirations...

I love the piping and stitching on this seat.

Bullet style blinkers

Josh

 

[gk45011]

I have been to the comet once. I met one or two people but it seemed like a fairly tight knit group. I really wasn't overly social. I am currently stuck with my jeep and party plates till january due to a HUGE error in judgement. I get to hang and build but the riding is around the neighborhood at best and is killing me while I build the new playtoy.