T350 project- bunch of questions

General discussion about Street two-stroke Suzuki motorcycles.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
Marshall
On the street
Posts: 19
Joined: Sat Aug 09, 2014 2:00 pm
Country: USA
Suzuki 2-Strokes: Suzuki T350

T350 project- bunch of questions

Post by Marshall »

I was given an old Suzuki T350 in pieces and I'm trying to rebuild it. I have a bunch of questions about it since parts and information seem to be hard to come by.

1. The fuel petcock is broken, and NOS replacements seem prohibitively overpriced ($100-$300). Are there any reasonable replacements anyone can recommend, or should I just buy a universal one?

2. All the fuel line is shrunken and hard as a rock. What size was the fuel line originally?

3. It looks like the motorcycle uses the battery as a voltage regulator since the rectifier only converts AC to DC and doesn't regulate the voltage. I bought a Tympanium voltage regulator to replace the rectifier. With no need for the battery to regulate voltage, can I replace it with a battery eliminator (capacitor)?

4. I had to buy a new wire harness and I see that there are 2 with different part numbers. What's the difference between 36610-18600 and 36610-18601?

5. What size chain does this bike use? And if I buy a new chain, do I have to buy new sprockets along with it?

6. I was missing the insulator blocks that go between the carburetors and the engine. I bought ones for the T250 but see that they're quite a bit smaller in diameter than the ports and carburetor on the 350 I have.

7. Does anyone know of a good rebuild kit for the carburetors? Again, the NOS parts are extremely expensive, like $90 for a needle. Are there any reputable rebuild kits out there?


Thanks for your help.
User avatar
jabcb
Moto GP
Posts: 4311
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: T350 project- bunch of questions

Post by jabcb »

Marshall wrote:1. The fuel petcock is broken, and NOS replacements seem prohibitively overpriced ($100-$300). Are there any reasonable replacements anyone can recommend, or should I just buy a universal one?
Depending on what you mean by broken, you may be able to rebuild the petcock.

I have Pingel vacuum petcocks on a few bikes, but they are pricey.
Pingel also has manual petcocks that are cheaper.

There are some cheaper manual petcocks -- perhaps another forum member can recommend one.
Marshall wrote:3. It looks like the motorcycle uses the battery as a voltage regulator since the rectifier only converts AC to DC and doesn't regulate the voltage. I bought a Tympanium voltage regulator to replace the rectifier. With no need for the battery to regulate voltage, can I replace it with a battery eliminator (capacitor)?
Correct, a stock T250/T350 uses the battery as the voltage regulator.

But the ability to start & run a stock T250/T350 without a battery varies.
Some bikes will start easily & run fine without a battery (except for the part where you burn out lights).
Others need a battery with a fairly good charge to start &/or run good at low rpm.
Marshall wrote:4. I had to buy a new wire harness and I see that there are 2 with different part numbers. What's the difference between 36610-18600 and 36610-18601?
What year T350 do you have?
This affects the wiring harness. Lights on/off is controlled by the ignition key on some years & by a left handlebar switch on other years.
Marshall wrote:6. I was missing the insulator blocks that go between the carburetors and the engine. I bought ones for the T250 but see that they're quite a bit smaller in diameter than the ports and carburetor on the 350 I have.
The T250 & T350 share lots of parts. But the carbs & exhaust are different.
Marshall wrote:7. Does anyone know of a good rebuild kit for the carburetors? Again, the NOS parts are extremely expensive, like $90 for a needle. Are there any reputable rebuild kits out there?
Carb jetting depends on which model year you have.
Those cheap carb kits don't have variations for the different jetting. So even if they had good parts, the parts might be the wrong ones.


An online parts manual will answer lots of your questions.
The service bulletins are also online.
Perhaps someone can provide the links, or I'll post them later when I have the time.
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
Marshall
On the street
Posts: 19
Joined: Sat Aug 09, 2014 2:00 pm
Country: USA
Suzuki 2-Strokes: Suzuki T350

Re: T350 project- bunch of questions

Post by Marshall »

jabcb wrote: Depending on what you mean by broken, you may be able to rebuild the petcock.
The round dome looking nut on the bottom that screws into the body was broken. Also, the rubber seals are shrunken a bit and dried up
jabcb wrote: But the ability to start & run a stock T250/T350 without a battery varies.
Some bikes will start easily & run fine without a battery (except for the part where you burn out lights).
Others need a battery with a fairly good charge to start &/or run good at low rpm.
I'm hoping the voltage regulator is able to correct the voltage so I don't get any problems with lights burning out. As far as the voltage being too low, I guess that depends on the alternator if I don't use a battery.
jabcb wrote: What year T350 do you have?
It's a 1972 I believe, with a build date of 10/1971


Thanks for the help.
alanr
To the on ramp
Posts: 260
Joined: Sat Jan 29, 2011 10:51 pm
Location: New Zealand

Re: T350 project- bunch of questions

Post by alanr »

if its a 72 or 71 you will need 36610-15103 main wiring harness.I brought mine from Suzukisimon.the numbers you have are for a 71 T250 only.I have both so I know.
CB360T
TT250
alanr
To the on ramp
Posts: 260
Joined: Sat Jan 29, 2011 10:51 pm
Location: New Zealand

Re: T350 project- bunch of questions

Post by alanr »

the chain is a 525.buy new sprockets that have 525 on them.
CB360T
TT250
alanr
To the on ramp
Posts: 260
Joined: Sat Jan 29, 2011 10:51 pm
Location: New Zealand

Re: T350 project- bunch of questions

Post by alanr »

insulater blocks are cheap on ebay.dont buy keyster carb kits,I made that mistake(didnt run well) so I cleaned the old parts and threw keyster away.I have seen petcock parts on Belgium ebay.dismantle and see whats needed.possibly new diaphram.look at my posts to get some ideas.I m not a know all but a know alot.
CB360T
TT250
User avatar
mike1161
On the main road
Posts: 129
Joined: Sun Aug 26, 2012 7:24 pm
Country: USA
Suzuki 2-Strokes: 1970 T350, 2012 Triumph Thruxton
Location: Palm Harbor, FL

Re: T350 project- bunch of questions

Post by mike1161 »

alanr wrote:the chain is a 525.buy new sprockets that have 525 on them.
Also, for the chain, you have to buy a regular (non O-ring) chain. I tried the O-ring chain, but it was too wide to fit. See the explanation in the last post in this thread:
viewtopic.php?f=9&t=7792&p=131055#p131055" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Current bikes: 1970 Suzuki T350, 2012 Thruxton
Previous bikes: '71 Honda CL350, '82 Yamaha 550 Seca, '86 Yamaha RD350, '88 Suzuki RG500 Gamma, '86 Suzuki VS700, '75 Kawasaki Mach II (S3), '12 Triumph Bonneville T100, '08 Triumph Daytona 675 SE
Vintageman
Expert racer
Posts: 1485
Joined: Tue May 18, 2010 5:38 pm
Country: USA
Suzuki 2-Strokes: Suz, Yam, Honda, Kaw.
Location: New Hampshire

Re: T350 project- bunch of questions

Post by Vintageman »

Carbs:

If you have good jet needle all else you can get new. Accept second pilot not sure how critical that is

The Keyster Kit comes with the early jet needle (first year) so you need to jet accordingly (i.e. Main jet change I think) else wont work properly. The fuel needle valve is OK too.

The early jetting or later jetting worked for me on the later T350 and T305 just fine. The later needle is obsolete. If you can get OEM # for it contact paul miller he still may have some. I upgrade to later jetting specs on my bikes when I made all shinny new

Crusinimage kit on eBay junk- for example jet needle does not match neither early or new T350 jet needle
Current registered, inspected, and running well 2 stroke motorcycles
74 GT250 (T350 upgrade),
76 GT250 (T350 upgrade),
71 T350,
70 T350,
74 GT380,
75 T500,
73 GT550,
75 GT750,
72 Yamaha DS7 (R5 upgrade),
77 Yamaha RD400 (Daytona Cyls),
73 Kawasaki H1 500
Marshall
On the street
Posts: 19
Joined: Sat Aug 09, 2014 2:00 pm
Country: USA
Suzuki 2-Strokes: Suzuki T350

Re: T350 project- bunch of questions

Post by Marshall »

alanr wrote:if its a 72 or 71 you will need 36610-15103 main wiring harness.I brought mine from Suzukisimon.the numbers you have are for a 71 T250 only.I have both so I know.
Will the one I have work? It looks like everything lines up. Am I correct in thinking that there are only minor variations?
User avatar
jabcb
Moto GP
Posts: 4311
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: T350 project- bunch of questions

Post by jabcb »

The T250 & T350 are pretty much the same except for items related to engine displacement (cylinders, intake, exhaust, etc.) & cosmetic items (fuel tank, side cover, oil tank, etc.)

There are two basic variations on wiring:
1) the lighting on/off switch location (left handlebar or ignition switch)
2) wiring differences because of headlight bucket.
If the headlight bucket has lots of room in it, then Suzuki used that room for lots of electrical connections.
If the headlight bucket has no room for wiring, then the electrical connectors are under the tank.

If the wiring harness you bought is setup for the lighting on/off switch & headlight bucket that's on your bike, then you should be able to make the wiring harness work ok without too much problems.

The two headlight bucket designs are:
http://www.partzilla.com/parts/search/S ... parts.html
Image
Image
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
Marshall
On the street
Posts: 19
Joined: Sat Aug 09, 2014 2:00 pm
Country: USA
Suzuki 2-Strokes: Suzuki T350

Re: T350 project- bunch of questions

Post by Marshall »

alanr wrote:insulater blocks are cheap on ebay.dont buy keyster carb kits,I made that mistake(didnt run well) so I cleaned the old parts and threw keyster away.I have seen petcock parts on Belgium ebay.dismantle and see whats needed.possibly new diaphram.look at my posts to get some ideas.I m not a know all but a know alot.

Do these things go by a different name on Ebay? If I search for "insulator blocks" or "carburetor insulator blocks" I get a couple of hits for the T250 but nothing else.
Marshall
On the street
Posts: 19
Joined: Sat Aug 09, 2014 2:00 pm
Country: USA
Suzuki 2-Strokes: Suzuki T350

Re: T350 project- bunch of questions

Post by Marshall »

jabcb wrote:The T250 & T350 are pretty much the same except for items related to engine displacement (cylinders, intake, exhaust, etc.) & cosmetic items (fuel tank, side cover, oil tank, etc.)

There are two basic variations on wiring:
1) the lighting on/off switch location (left handlebar or ignition switch)
2) wiring differences because of headlight bucket.
If the headlight bucket has lots of room in it, then Suzuki used that room for lots of electrical connections.
If the headlight bucket has no room for wiring, then the electrical connectors are under the tank.

If the wiring harness you bought is setup for the lighting on/off switch & headlight bucket that's on your bike, then you should be able to make the wiring harness work ok without too much problems.
Mine is definitely the large headlight. There were all sorts of connectors in there. Unfortunately the previous owner cut the harness in half and clipped off a lot of the connectors.
User avatar
jabcb
Moto GP
Posts: 4311
Joined: Mon Dec 13, 2010 4:32 pm
Country: USA
Suzuki 2-Strokes: 69 T350 thru 75 GT750
Location: southwestern Pennsylvania

Re: T350 project- bunch of questions

Post by jabcb »

Intake parts diagram: http://www.partzilla.com/parts/search/S ... parts.html
The carb insulator part number is 13129-18000

Looks like Paul Miller has the NOS part.
http://www.ebay.com/itm/Suzuki-SM30K-Sn ... 1039769045

You should try to get a complete gasket set.
Paul Miller probably has them. His phone number is 860 828-1771
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
alanr
To the on ramp
Posts: 260
Joined: Sat Jan 29, 2011 10:51 pm
Location: New Zealand

Re: T350 project- bunch of questions

Post by alanr »

the wiring harness will not fit in the headlight,(it is for the T250 under tank fitting)you may get it to fit with lots of patience and some swearing and mistakes,I would sell and buy this.http://www.ebay.co.uk/itm/Suzuki-T500-T ... 93f6408d.I" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; did and it took an hour to fit.no swearing or mistakes only beer afterwards.before you buy anything (if you are in doubt)ask here first.if I had done I would have saved plenty.learn from our bad buys.this will work if its definitly a 71.http://www.ebay.co.uk/itm/Suzuki-T500-T ... 27e9aa98c3" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; :up:
CB360T
TT250
Post Reply