GT550 main jet extenders

Need some help? Put your question up here. Many years of experience on the board to help you get up and running.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
User avatar
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

GT550 main jet extenders

Post by jabcb »

Working on the GT550 cafe build. Am cleaning the carbs & rejetting for expansion chambers + pod filters.

The carb uses series 192 needle jets + large round jets (Mikuni N100.604) + jet extenders. I think the extender part # is 13330-34010, which is NLA.
I have new needle jets & main jets.

The existing main jets + extenders are shown in the pic. They are stuck together. Any tips on separating them without ruining the extenders?

ImageMainJetPlusExtender_1142 by jabcb, on Flickr
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
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: GT550 main jet extenders

Post by sportston »

Wire brush, then plusgas, allow to soak, then heat. Repeat as necessary.
User avatar
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: GT550 main jet extenders

Post by jabcb »

Thanks for the tip.

I bought a second set of carbs because one of the float bowls is bad. So fortunately only need to get 3 good extenders out of the 6 stuck-together ones I have. Hopefully that puts the odds in my favor.
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
sportston
Expert racer
Posts: 1119
Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: GT550 main jet extenders

Post by sportston »

Also you may find shock therapy would work. An impact driver might help. Although if it was me I would try clamping the jet in a vice while trying to loosen the extender using a spanner. Whilst holding the ring end on with your left hand, thump the other end of the spanner with your right palm. The sharp shock will help it free.
Vintageman
Expert racer
Posts: 1483
Joined: Tue May 18, 2010 5:38 pm
Country: USA
Suzuki 2-Strokes: Suz, Yam, Honda, Kaw.
Location: New Hampshire

Re: GT550 main jet extenders

Post by Vintageman »

just maybe this is it ->

https://jetsrus.com/individual_parts/002_207_su.html" onclick="window.open(this.href);return false;
Current Bikes
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),
User avatar
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: GT550 main jet extenders

Post by jabcb »

I had asked the same question on the Suzuki GS forum & got some good tips.

Was much easier than I expected. I applied Seafoam DeepCreep a few times over a week. Then used my heatgun to heat the extender wile holding the main get with visegrips. (This made the extender a bit hotter than the main jet.) Then it only took a moderate force using a wrench + visegrips to break it loose.
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
Post Reply