Pilot Jets?????

[DGXSER]

Just to be clear, synching is done wiht the synch screws only. The mixture screws can adjust vacuum, but it will be a subtle change, nothing like the change of adjusting the synch screws.

[spayne83]

Carb Sync

I used this to sync the carbs

http://www.ebay.com/itm/Carburetor-S...81aa6e&vxp=mtr

It has a plastic screw valve to limit the vacuum oscillations that the gauge shows so I tightened it down so that the needle was steady but still moved when throttle was applied.

I just rebuilt the carbs and I didn't see any of the previous tips broken off and I only snugged down the idle mixture screws down to finger tight where I just started getting tension and then backed them all off 2 turns. However no matter what I did with the screws there was absolutely no change in the vacuum.

When riding it is sluggish off idle and then picks up around 3-4000 rpms but will start popping around 6-7000 and there is no increase in power from 1/2 throttle to full throttle, so I think that I am running really lean.

[TopCatGr58]

Hey Spayne,

Okay, you said POD filters, what type..inexpensive EMGO generic cones, or the fancier XS brand from MikesXS or Partsnmore.com? And how do you have them mounted to the carbs...directly or with velocity stacks/tubes?

The cheap EMGO filters have prominent mounting lips that interfere with the air flow to the inlet bell ports...and cause problems around the 6krpm.

You said you just rebuilt the carbs....but your symptoms sound like a clogged pilot jet circuit! Did you use carb cleaner and spray it thru the pilot jet tower and ensure that it came out the pilot jet screw hole as well as the little holes on the inside/underside of the engine side of the carb throat??

Tweeleft, glad you found the possible problem with the pilot jets, hopefully with the right size, it'll behave better. Let us know what happens.

T.C.

[spayne83]

They are the cheap filters, but I spaced them out from the opening about 1/4" so there should be air flow. I will be ordering a stock air box to get the velocity stacks to mount the filters.

I soaked for at least a day in Yamalube and I did spray out everything, but I am going to rejet with 145 mains and 45 pilots (per a suggestion in another thread) and double check my float height, so I will spray that passage out again and check my plug color.

[tweeleft]

Ok. This forum is outstanding. I've learned how to colortune,sync, read plugs,jetting carbs, and a s''h lot more.

Update:
Replaced 45 pilots with 42.5s
Replaced 142.5 mains with 137.5s(may go to 140s)
Set needle clip one notch rich
Idle screws at 2 turns ish

Test ride had to feather throttle or she would cough once rpms she was ok.
Back in the garage. Colortune,sync. Reved off idle with colortune got mix screw on the sweet(I HOPE lol). Damn raining
Will do test ride soon

[skids]

Go back to the middle clip on the main needle setting. They are adjustible but the adjustment settings are too extreme.

[tweeleft]

Ok tank is still in tuning mode

[tweeleft]

Good test ride. Didn't lower the slide needle clip but will. She sputters a little just before wot. Thinking that's probably it. Hope to do this weekend

[spayne83]

Not sure if you have seen this:

http://www.factorypro.com/tech/carbt...m_engines.html

Hope it helps

[mikubuilder]

Put some Seafoam in your gas for a couple of gas fill ups, that should clear up anything you've missed in the carbs

[tweeleft]

Not sure if you have seen this:

http://www.factorypro.com/tech/carbt...m_engines.html

Hope it helps

Yes I've seen this. As to why I'm doing the slide needle adjustment next. Thx

[tweeleft]

Seafoam is on my list. Thx