Running too lean?

[Cubby's XS1100]

You'll have to do a valve adjustment if you change cams (but haven't you been meaning to do that anyway?....)

Are these the the "puck type" of valve adjustments??? And where would I get them??

[Cubby's XS1100]

You'll have to do a valve adjustment if you change cams (but haven't you been meaning to do that anyway?....)

Do these valve adjustments need those "pucks"? Where do I get those at??

[crazy steve]

Grab that TCI in any case... those are hard to find!!

[crazy steve]

The 'shims' can be gotten online or at most metric dealers (usually on a 'trade' basis). You don't need new ones, used is fine, they just need to be the right marked thickness. Between the two motors and with moving them, you may not need any...

[DGXSER]

There was more to it than the timing and cams, valves and piston also changed.

While the 78 was the strongest, I have to wonder how many folks that are typical riders could ever feel the difference.

[Cubby's XS1100]

I took a look at it last night and thought the same thing. Knowing Yamaha like I do, they probably changed a few more things between these years and models than just the cams. So I am officially chickening out(sorry Steve) and I am getting the 81 TCI box from the guy I got the motor from. I will keep you guys posted on the outcome................Cubby

[DGXSER]

The bike will run fine with the cam swap, and timing swap. It will run fine with just the timing swap. Its a matter of how close you want to get to the 78 performance and how much time and effort you want to invest to get it.

[skids]

The 'shims' can be gotten online or at most metric dealers (usually on a 'trade' basis). You don't need new ones, used is fine, they just need to be the right marked thickness. Between the two motors and with moving them, you may not need any...

Take your caliper with you and compare diameters. Some are .5 mm different.

[motoman]

There was more to it than the timing and cams, valves and piston also changed.

While the 78 was the strongest, I have to wonder how many folks that are typical riders could ever feel the difference.

+1.......the early ones pulled harder on the top-end.......later ones,(80-82) pulled harder on the bottom end......basicly a wash-out and I would use the later 4RO box with your later motor.

[Cubby's XS1100]

The 78 carbs do have a screw over the pilot jet as they feed the pilot from the main jet, there is a crossover under the main jet in the emulsion tube section.
The newer style carbs do use a leaner main jet 110-120.

Is there any way to clean out this cross over to the main jet? I got the TCI box last night and it runs pretty nice 3 grand and up but no idle. I know the pilots are clean so I think they are not getting fuel to them. I will pull the carbs (again) tonight when I get home. And here is a dumb question, what would happen if I just remove the screws that cover the pilot jets??.........Cubby

[natemoen]

If you pull the main jet, emulssion tube and the pilot jet put you can see the little crossover passage. You could use a toothpick or a little passage brush to just scrub it put.

If you remove the screw you would get too much fuel in both circuits.

[skids]

If you remove the screw you would get too much fuel in both circuits.

I am not too sure, but I think the cap under the pilot jets is above the fuel level. You might be sucking air in both main and pilot curcuits if the cap is removed.

[natemoen]

I am not too sure, but I think the cap under the pilot jets is above the fuel level. You might be sucking air in both main and pilot curcuits if the cap is removed.

Maybe at WOT but if that were the case how would the late model carbs get any fuel in the pilot circuit....those towers are all the same height.