Roughness Off Idle - Continued from Electrical Thread

[Guest]

Pete, I will be watching your thread for the jetting procedure that you will use. You will have to get it on the road first though, as it's hard to do the jet testing by running the bike in the shed. A few miles on the tarmac can tell you a lot.

That point is getting closer every day, just uploading pic's and vid's from today's fun actually...

I tell ya Don, I'm getting quite antsy because the light at the end of the tunnel is glowing brighter...

 

[Suzuki_Don]

Another UPDATE:

Yesterday (Sunday) I removed the ignition cover, loosened the 3 screws holding the Dyna S modules base plate and retarded the ignition on both sets of cylinders by a couple of degrees. Took it for a ride so it was fully warmed up. Put it back in the shed, threw the timing light on it, doing 1-4 and 2-3 in turn and both sets were exactly the same on around 11 or 12 deg initial advance. Have not checked for pinging yet, that will take a longer ride under different conditions.

 

[Suzuki_Don]

UPDATE: I took the bike for a three day run and it was running quite well, although it is still pinging a bit at low revs when opening the throttle. I need to retard the Dyna a bit more.

I think it is set at 12 deg initial advance at idle, and I think it should be 10 deg as on the 650 motors.

The quandary I am in is that the 650 handbook states that total advance is 40 deg for that motor. I have 550 bottom end, 650 top end. So it should be timed to the 650 specs IMO. The 550 advance unit which I am using operates at 17 deg initial at idle and 37 deg total advance.

So if I retard the Dyna base plate to get the 10 deg initial advance at idle, that means the total advance is being retarded by 7 deg as well, which would give me a total advance of only 30 deg.

Which I am worried will damage the motor at higher revs.

COMMENTS PLEASE - advice even.

Also see below a couple of the plugs I pulled from my motor after the three day run - What do you think of their colour. Particularly the black soot around the threaded base of the plug. And how do the centre and side electrodes look.

Thanks in advance.

 

[Guest]

Don, is the Dyna S fully electronic or does it still use the mechanical advance like mine?

If it uses the mechanical advance, can you not use the weights from a 650?

Alternatively, the 80 - 82 450's have similar sounding timing with the 10/40 setup, so maybe some weights from one of those will fit?

Of course I'm probably barking up the wrong creek altogether but it might be worth a thought...

 

[Nessism]

Don,
Retarding the ignition at idle will retard at high rpm's as well. Only down side is loss of power and economy.

Might be time to play with the weights and springs between the two advancers so you can get an optimal set up.

BTW, those plugs look good to me.

 

[Suzuki_Don]

I might try and modify the 650 advance unit that I have. It is about a 1/4" longer than the 550 unit currently on the bike. Or I could file the stops on the 550 unit so the bob weights can advance a bit further at higher rpm. And then check with timing light at full advance after marking the 40 deg mark on the timing plate (on advancer).

Pete, unfortunately the bob weights will not swap over. Good suggestion though.

 

[Guest]

I might try and modify the 650 advance unit that I have. It is about a 1/4" longer than the 550 unit currently on the bike. Or I could file the stops on the 550 unit so the bob weights can advance a bit further at higher rpm. And then check with timing light at full advance after marking the 40 deg mark on the timing plate (on advancer).

Pete, unfortunately the bob weights will not swap over. Good suggestion though.

That's a pity Don, but I guess it would be too easy right?

I guess the other (expensive) alternative would be a programmable ignition...