Carb Question

[Tex]

Hello All,

   So I plan on changing to #40 jets today. I remember last time I pulled the carbs I had a hell of a time putting throttle cables back on.  Is there a trick to this? Also with the 40 jets in what would be a good base line to state with the mixture screws. Thanks.

Scott.

[Pat Conlon]

Yea Scott, it's a pain...I like the splitter box on my '84...but on my '92 here's what I do...

Loosening up the threaded cable adjusters so that the cables come loose....you need them loose for the slack.
I then wiggle (up and down) the carbs free of the manifold.
Then with the carbs free I can reach with my one hand and with my fingers, open the throttle plates. You have to have the carbs off first to get to the plates located on the engine side of the carbs
The other hand I put a screw driver handle in the throat of the carb to hold the throttle plates open.

This opening of the plates rotates the cable pulley around so I can get to the cable barrels and get them off.

Instead of a screwdriver handle, you can clamp on your Vice grips to the linkage to hold it open...
Either way, open the plates and hold them open....the cables will be much more accessable for removal.

With #40 pilots, starting point is 2.5 turns out on your idle mixture screws...final adjust per blip test.

Cheers laddie..

[Tex]

Once again thanks Pat worked like a charm. 40's are in. I'm out about 3 1/2 turns. At 2 1/2 when I hit the throttle it bogged for a split second. Even and 3 1/2 still a little hesitation when I hit the throttle hard from idle. Maybe I'll go out another 1/2 turn.

[Pat Conlon]

Are your carbs synced?

You've put in fatter pilots. I'm surprised you're out that far...

Try 1/4 turn increments.

On your test ride remember: after the engine heats up...if the idle increases, you're too fat.

[Tex]

Too fat? Well I synced last season. Maybe I should do them again.

[fjbiker]

Hi Scott,

Did you ever end up adjusting your pilot screws out more than 3.5 turns and if so, what was the result?

My Canadian '84 FJ1100 came with a #40 pilot jet from the factory and the original pilot screws settings ranged from 3.5 to 4.75. I just rebuilt the carbs and replaced all the O-rings and brass. When I put it back together, I decided to try the screws at 2.0 as per my manual. I re-synced the carbs.

Initial throttle response was ok but once the engine got hot, I had a major hanging high-speed idle issue. It would float around 1500 rpm for 60 seconds or more before returning to 1000.

I turned the pilot screws out to 3.5 and the issue disappeared except on the very odd occasion when it might hang just for a second or two before returning to normal. I'm thinking of turning it to 3.75, a little closer to the original settings, to see if it clears up that occasional slight hang. 

Just was wondering if you saw a similar issue.

Thanks, Mark

[Tex]

Hi Mark,

   Mine are turned out someone where between 3.75 and 4. She runs good there. But actually when I bring them in she bogs down and if there out to far she will hang up. Someone correct me if I'm wrong but the more you screw them out the more fuel is going in and that's why they tend to hang if out to far.

[fjbiker]

Thanks for the update.

I believe you're right that turning the pilot screw out will make the mixture richer. I am interpreting the hanging idle as being caused by a lean condition. Maybe I'll try turning it out another ¼ turn and see if it has any effect.

Mark

[a.graham52]

i agree with turning the screws out make it richer!

what iv always understood was a hanging/ slow to return idle was due to a lean condition. too rich of an idle will bog/foul plugs.

something else i was told was for like cruising (and probably applies in a lot of places), if you have stumble/missfire feel (and you know its not igntion), then you have a rich condition. a lean condition is just a lack of power feel, "flat spot". UNLESS your wicked, wicked lean!