'75 GT 550 Timing

Getting your blazingly fast Suzuki powerplant to perform even better!

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Apexxn
Still in the Driveway
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Country: United States
Suzuki 2-Strokes: H1, RD, NSR, MT1

'75 GT 550 Timing

Post by Apexxn »

Are you guys still setting the timing at the service manual suggested 3.37(top of my head don't have the manual in front of me). I know on some of the other vintage strokers I don't go with as much timing as the manual states. For instance Yamaha RD manual 2.3 and now a days everyone sets it at 1.8.
GTandcbr
Yeah Man, the Interstate
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Suzuki 2-Strokes: suzuki gt 550j
Location: Wales

Re: '75 GT 550 Timing

Post by GTandcbr »

Clymers says B.T.D.C 3.37 or 0.132 in and it also says to do the left pot first.
98 carb Blackbird and GT550j
Craig380
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Location: Manchester, UK

Re: '75 GT 550 Timing

Post by Craig380 »

I found my GT380 preferred the timing to be slightly retarded compared with the factory recommended 2.25mm BTDC. I used to run it at 1.9mm BTDC, and it ran happier there.

It always felt a bit 'on edge' to me, at 2.25mm. Dyno tests have shown that on a stock motor, having the timing retarded by a fraction makes no difference to power and torque anyway, and it's far less likely to hole a piston ...
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
Vintageman
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Suzuki 2-Strokes: Suz, Yam, Honda, Kaw.
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Re: '75 GT 550 Timing

Post by Vintageman »

If you retard the timing over stock you loose power with respect to how the bike was designed. The GT550 is not high revving even if you mod it a little. It has a very broad mid-range :up:

My Yams, I run stock timing :up:

I run chambers on all my bikes.


Try it both ways see what you think.

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