New member intro, GT380 resto project.

Photos and progress of your restorations, even bikes you had but no longer own.

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jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

New member intro, GT380 resto project.

Post by jeffz »

Hi Everyone,
I just got a 1973 GT380, that has been sitting for about 10 years. Naturally, it needs a lot of TLC to get on the road again. I'm 63 and have refurbished a few
bikes over the years, but am not an ace mechanic. The seller told me the bike didn't run well due to excessive play in the ignition timing shaft. I'm presently going thru the fuel system, but need info on the bearing(s) on the timing shaft. I haven't removed it yet, but can save some time if someone here has done this job, and can tell me the specs on the bearing so I can have the replacements in hand before disassembly. TIA for any help in doing this unfamiliar job.
I don't presently have an image hosting site, so no way to share pics, but I will try to get some up to show the resto progress.
Thanks!
Jeff in AZ
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jabcb
Moto GP
Posts: 4240
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: New member intro, GT380 resto project.

Post by jabcb »

The GT380 points cam shaft has a plastic gear. The manual instruction for setting the points show using a wrench on the points cam nut to turn the crank. But that will eventually break the plastic gear.

Suzuki recommended turning the rear wheel in 6th gear when adjusting the points. But my GT380 doesn’t have a centerstand so that isn’t very practical. I remove the plugs to make it easy to turn the crank & use the kickstart lever.

See: http://www.ozebook.com/compendium/techb ... 0mc119.pdf
Check you motor VIN to see if you have the updated drive gear & only need a new plastic driven gear.

Fortunately the plastic driven gear is still available from Suzuki. See: https://www.partzilla.com/catalog/suzuk ... aker-denso

You bike has ignition & alternator by either Denso or Kokusan. Make sure you get the correct parts when ordering points, condensers & brushes.


I use Flickr to host images. Its free & easy to use.

Manuals & service bulletins are here: https://www.oldjapanesebikes.com/mraxl_ ... /index.php
I have a preference for hardcopy manuals — you can get them via eBay.

Crank seals can be an issue on these bikes if they sat unused for a long time. Some members have techniques for rejuvenating those seals.

I’m around your age and started working on vintage bikes as I was winding down towards retirement. Started out with minimal skills & lots of time.
Working on these bikes can be a great retirement hobby. So just take your time, do some research & have fun!
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
jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

Re: New member intro, GT380 resto project.

Post by jeffz »

Hey, thanks for all that info. You sure have alot of bikes!
I will check my vin# to see what I have. I forgot about the crank seals, sure hope it doesnt spring leaks. Assuming I can get it running, lol. I just got the stink out of the gas tank, long way to go yet...
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Alan H
Moto GP
Posts: 3160
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: New member intro, GT380 resto project.

Post by Alan H »

Welcome to the asylum Jeff. Nice intro. Good luck with tbe triple work.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

Re: New member intro, GT380 resto project.

Post by jeffz »

[img]37FFA2E1-5DE4-44FD-9FC6-00DE9DB60BA7[/img]

Oldjapanesebikes is a great resource. Found the parts nos. I needed, and the parts online. Yay!
Thanks
dollydog
Yeah Man, the Interstate
Posts: 630
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: New member intro, GT380 resto project.

Post by dollydog »

this place is a good source for part numbers and being able to see if parts were changed over the years, it's invaluable :D i use postimage to post my photo's, it's also free :D
cheers, dd.
https://alpha-sports.com/suzuki_parts.htm" onclick="window.open(this.href);return false;
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.
jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

Re: New member intro, GT380 resto project.

Post by jeffz »

dollydog wrote:this place is a good source for part numbers and being able to see if parts were changed over the years, it's invaluable :D i use postimage to post my photo's, it's also free :D
cheers, dd.
https://alpha-sports.com/suzuki_parts.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
I appreciate that.
I joined Flikr, but am such a tard with computers, I have to learn how to post images again. Can't find intstructions there or here. I'll get it eventually.
dollydog
Yeah Man, the Interstate
Posts: 630
Joined: Fri Aug 11, 2017 7:09 am
Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: New member intro, GT380 resto project.

Post by dollydog »

i'll walk you through it, jeff :D
save your photo's to a reasonable size on your pc or laptop.
go on postimage.org and click on 'upload' - top left.
new page opens. click on 'choose images'.
pop up will be your computer - mine opens up on my desktop, yours may be different.
find the image you want to upload and click it.
uploading bar will fill up and it will say 'completed'.
bottom of page there will be several options.
click on 'HOTLINK FOR FORUMS' and copy.
write your post and to put your photo where you want, right click and 'paste'.
the link will show, but the photo won't until you post your post :D
all done and nice shiny suzuki for all of us to see. sounds complicated, but it's easy :D
hope this helps, and sorry i don't do flickr.
cheers, dd.
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.
jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

Re: New member intro, GT380 resto project.

Post by jeffz »

Image
Yay! Thank you dollydog! Flickr can now go and get stuffed...
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jabcb
Moto GP
Posts: 4240
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: New member intro, GT380 resto project.

Post by jabcb »

Nike bike. :up:

The motor & forks are for a 1974 or later model. The gas tank is for a 1974 model.
For pics of the different model years see: http://suzukicycles.org/GT-series/index.html

The VIN is GT380-XXXXX. You can figure out which model year you have by looking up your XXXXX in these chart:
http://www.ozebook.com/compendium/suzi/ ... /page1.gif
http://www.ozebook.com/compendium/suzi/ ... /page2.gif
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
jeffz
On the street
Posts: 35
Joined: Wed Sep 04, 2019 2:34 pm
Country: USA
Suzuki 2-Strokes: GT380
Location: Mesa, Arizona, USA

Re: New member intro, GT380 resto project.

Post by jeffz »

Thanks for all that info. That Jarmo dude is really into Suzukis!
My bike was built in 12/73. It is titled as a 73, but its frame no. puts it as a 74.
What puzzles me is the 74 was the only year with CV carbs. I thought CV carbs have a rather large diaphragm on top. Like the BS34's on my KZ1000.
My carbs look like VM's, with the cable going straight down into them. They also have a common sorta frame on top, and fuel rails connecting them, again
like the 4 carbs on the KZ1000. I will find out more when I remove them later this month.
I hate the vacuum petcock. Stupid idea, not having a secure fuel shutoff. A problem waiting to happen. A friend says he has a Pingel to fit me. I already
ordered some rubber parts for the petcock, and a cheapie complete petcock that might fit, but it's vacuum, too. If he gives me a deal on the Pingel, I'll get it.
I got a proper owner's manual (L model) today. Kinda pricey at $24., but I really like old, authentic literature. It has pictures of the plant and test track in it. Cool!
I also got a pair of new shocks, which are surprisingly plentiful on (the auction site we don't name), for ~ $75. Cheap compared to what I paid for Honda units
20 years ago. These are 99% identical, if you look close. Not marked Suzuki, but neither are the ones on the bike. If they are knockoffs, they are good ones.
I will tackle the breaker cam shaft soon. I hope the gear isn't broken. I will order the bearing and oil seal tonight. I will get pics of the job.
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jabcb
Moto GP
Posts: 4240
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: New member intro, GT380 resto project.

Post by jabcb »

According to the online parts diagrams at Partzilla, the 74 through 77 models have the same carbs.
SuzukiCycles.org has lots of good info but it its not 100% perfect.

The later model GT750s have CV carbs & they look as you were expecting.

The tank opening for the petcock is a rather narrow slot.
Pingel petcocks use a round opening. The have adapters that go between the petcock & slot. If you go with a Pingel, you will have to widen the gas tank slot a bit.

A downside of widening the slot is that you can’t switch back to a stock petcock because of the widened slot.
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
karl pa
To the on ramp
Posts: 490
Joined: Sat Sep 05, 2015 3:14 pm
Country: us
Suzuki 2-Strokes: GT
Location: southeast pa

Re: New member intro, GT380 resto project.

Post by karl pa »

jeffz wrote:I hate the vacuum petcock. Stupid idea, not having a secure fuel shutoff.
You can modify the petcock to be a positive shutoff. On the newer style what I do is tap threads in the two ports of the diaphragm chamber, then plug them with set screws and epoxy, then connect the two passages on the inside of the handle valve by removing the material to make one reverse J shaped passage rather than the two separate. I leave out the diaphragm and plunger but put the cover back on. No one can tell, everything looks original.
When the handle is pointing front it is in the off position, pointed down is on, pointed rear is reserve.

I modified the petcock on my 73 GT550, plugging the two holes to the diaphragm, and replacing the valve handle 180 degrees reversed.
When the handle is pointed up is in the off position, but unfortunately I don't remember if down is on or reserve. One of these days I might remember when I am sitting along the side of the road with an empty tank.
By the way, nice bike and welcome.
Last edited by karl pa on Wed Sep 11, 2019 5:24 pm, edited 1 time in total.
76 GT185
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe
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Alan H
Moto GP
Posts: 3160
Joined: Thu Feb 16, 2012 11:50 am
Country: England
Suzuki 2-Strokes: 4 x GT550s - J, M, A, B.
Location: The Republic of South Yorkshire

Re: New member intro, GT380 resto project.

Post by Alan H »

If you don't like the diaphragm tap, just fit one of these between the normal tap & carbs. Ebay item 372757410027 or similar. Put a piece of tape on the speedo with 'TAP' on it as an aide memoire to remind you to use it, and also get a laugh when people look at your bike, see the tape and tap the clock.
Gives me a laugh every time with my GT750. Honest!
Cheaper option too, or just fit a tap repair kit. They work as well, so long as you don't lose the spring......
Last edited by Alan H on Wed Sep 11, 2019 4:59 pm, edited 1 time in total.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
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Evans Ward
To the on ramp
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Joined: Mon Oct 24, 2016 12:35 pm
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Suzuki 2-Strokes: 76 GT750, 72 H2 750, 84 RZ350
Location: Macon, GA. USA

Re: New member intro, GT380 resto project.

Post by Evans Ward »

Welcome! That’s a nice looking bike to start with. You’ll find this site helpful and friendly.
1976 Suzuki GT750 (Maui Blue), 1972 Kawasaki H2 750 Mach IV (Candytone Blue), 1984 Yamaha RZ350 (KRR- Yellow/ Black).
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