im about to blow up the bike

[tjfisher30]

Originally posted by TopCatGr58
Okay TJ,

Did you remove the main jet nozzle/ and ensure the holes are clean/clear? Are your vacuum diaphragms working properly, no holes?


T.C.

are you talk abut the emolsion tube the tube the slide needle runs threw ? how do you get that out safely

[81xsproject]

I think (at least on the late model carbs) you just use an 8mm wrench.

[randy]

tjfisher30;

Yes.

The emulsion tube is the thing that the needle slips into. You can get it out by loosening the main jet and tapping the main with a soft (plastic mallet, screwdriver handle) object. That should break it free (depending on crud factor), then unscrew the jet and you should be able to push the tube out. Watch the keyway when you re-install it, it only goes one way.

Clean each hole with a solid #22AWG copper wire (phone wire, bell wire) until you can see light through them, then blow them out with compessed air. that should do it. repeat three more times

[chopwatchagot]

TJ, I certainly don't want to add any confusion to an already very frustrating situation, but as I found out in rebuilding the "funky" carbs T.C. is talking about, the jetting situation can be even more bewildering! Yamaha must have been doing some last minute experimenting between model years but unfortunately, they have way better test equipment than we have. I believe it was Todd who posted some Pics and a very good description of those carbs, the ones with the tunnel between the main tower and the pilot jet tower. Well, in mine I found #115 and #120 main jets in place( not the 137.5's). Thinking that with the pod filters and 4 into 1 header I should richen up the fuel mixture I tried the 137.5 mains as TC suggested. It was WAY too rich so I worked my way back down to the 115's and 120's that were in there originally and it runs great. I really don't know why, but at this point I don't really care. Anyway, best of luck in figuring it all out.

Dean

[tjfisher30]

ok good news went threw the carbs again and they are not the funky ones i clean them 3 times sunday with 3 cans of carb cleaner all ports clean all jets clean and clear did the T.C. stacks for the pod filters ... ok put them on messed with them for a few mins cranked her up and its alive ran rough with a little poping them warmed up and ran better .. took her around the apartment about 10 mins low end really sluggis them the mains kik in around 4 grand or so the tack is bouncie and them she runs strong i would say i need to sync them in ? what you guys think oh ya new plugs looked a little white with a start of brown blackist

[Ken Talbot]

Yes, if you have not vacuum sync'd them, they need to be done. These big 'ole bikes will run on two cylinders, and they will run with out-of-sync carbs, but you won't know what they can really do until to get it all right.

[tjfisher30]

shes running

i tweeked her today ajusted the mix screw 1/4 turn at a time till i found the sweet spot sych them in best i could with a homemade vac gauge what a pain that is they are probly still out but real close ill buy a merc stick or try and borrow one later but i can clean her up now and register her what are the rubbers on the head between the fins?

[HankD]

I don't recall seeing you mention anything about the jet needles. They are responsible for the range in between the pilot jets and the main jets, from a rpm perspective. If your needles are adjustable with the c-clips, I would suggest lowering the clip one position which will raise the needle allowing more fuel to come into play sooner. If you don't have adjustable needles, you can shim them up with small washers. Since you have gone to pod filters, you may also need to address the pilot jets.

Something else, are you sure your carb bowls have enough fuel in them? If the fuel level is too low, it will generate a lean condition, which you abviously don't need given the additional air flow.
Hank

[rev79xs11]

If you had the diaphrams out they may not be seated properly causing a leak and no main operation. You can sheck them when you have the float bowls off and there is absolutely no gas in the carbs (like after cleaning and reassembly). Use a shop vac to supply vacuum to the front of each carb one at a time. Open the butterflies and watch the slider to make sure it moves freely. Check each carb. I always check them cuz it ticks me off when I realize I screwed one up and have to tear down again.

[tjfisher30]

needles adustment

ok been out for awhile and i need to move up the needles but how do you shim them up the bottom has the plastic clip and a centering point (the little tit for lack of a better term) ? do i cut it off and shim up? i do not have the adustable needles

[wingnut]

80-81 card needles

If you pull up on the needles while holding the plastic you will find that they will move up some. Remove the clip and put a .025 inch thick washer under the clip and reinstall the clip. Push the needles back down into the plastic and put it all back together. Set the pilot screws to 2.5 turns out from seated and she should run real strong. My bone stock SH with 110 mains really likes this set up.

I just made a small clarification about the pilot screws to avoid any confusion John

[tjfisher30]

Re: 80-81 card needles

Originally posted by wingnut
If you pull up on the needles while holding the plastic you will find that they will move up some. Remove the clip and put a .025 inch thick washer under the clip and reinstall the clip. Push the needles back down into the plastic and put it all back together. Set the pilot screws to 2.5 turns out from seated and she should run real strong. My bone stock SH with 110 mains really likes this set up.

I just made a small clarification about the pilot screws to avoid any confusion John

thanks worked out perfect running great finally and im running 112.5 mains