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**TopCatGr58** · 08-22-2009, 03:10 PM

It's been a while since I've read the tech tips, I didn't write or contribute the ones that already existed. I've been planning on making some new ones complete with nifty photos and such. I had hoped that one of the other mods that works on these often might have thought about taking some shots and doing a nice walkthru writeup, but he's been quite busy with several other projects as well!

Replacement gaskets are available, but if they were not leaking, and you don't tear them up when taking the bowls off, then you can reuse them. The pilot jets are small, made of brass and can be fragile, the slotted ends can break apart/off. Suggested that once you expose the pilot jet tunnel by removing the large cap screw that seals it, that you squirt some PB blaster in there and let it soak a while...hours! Also, if you have a heat gun, blasting it in that area can also help the aluminum to expand and contract breaking the corrosion bonds that can occur. And be sure you have a tight fitting slotted screwdriver....grinding the sides off of one if need be to get it to be a snug fit. Then I use a light hammer to tap on the screwdriver once it's fitted into the brass pilot jet slot, helps the driver to bite into it and also helps to shock the parts again breaking corrosion bonds. And then break it loose with a QUICK snap twist....not a slow turn.

Inspect the vacuum slide needle and the MAIN jet for signs of wear, rubbing on the needle and inside the main jet orifice..out of round. IF present, then they would need to be replaced. Otherwise, just cleaning will be sufficient.

The 79F uses a fiber washer under the needle seat, unscrew the seat, and clean the fuel filter screen on the bottom of the seat. These are plastic, and can be fragile, you can spritz with carb cleaner, or soak in cleaner, but be careful if you try to pry them off the seat. The needle itself can get a groove worn on it's tip, and you can try polishing it down with fine emory cloth. Q-tip and metal polish down in the seat can help smooth it's surface out so that it'll make a good seal with the valve.

EXTREME care should be used with the pilot SCREWS, their tips are fragile and easily broken, getting stuck in the pilot screw hole in the carb body. When putting it back in and tightening down to a gentle seat...use only 2 fingers to turn the screwdriver and even put your finger in the carb throat to feel the tip poking thru as you seat the screw before you then back it out the 1.5 turns before tuning.

Be sure to spritz cleaner thru the hole/tunnel in the float bowl to ensure that it blows out that other hole down in the bowl...this is the starting jet, use fine wire to poke in there to push/break apart gum/varnish IF it isn't free flowing!

Aside from the bread stick tie, you can also visually set the Pre-Synch by using one of the 3 little ports in the upper throat of the carb to determine how closed the butterflies are set at.

Hopefully you've read the tip for removing the float pins? They are not exactly even in thickness, but are slightly larger at the head, and that's why they STICK in place. Once you carefuly remove them and haven't broken any posts...you might want to use that same fine emory cloth to spin the pin inside of to slightly narrow the pin so that it slides easily thru the post hole without binding/sticking. The float bowl's contours locks the pin in place, so it doesn't need to be so tight, this will facilitate future disassemblies without the worry of breaking off posts when removing the pins!

Others may pitch in more info!
T.C.

**Larrym** · 08-22-2009, 03:34 PM

Join the Carb Club!!

Clerek,

If you've read the tech tips then you're well ahead of the game. I was a little intimidated at first and that's the right way to approach this task: you're concerned and want this to go right.

I did the process on two banks of carbs. (Three actually but the third bank is only for parts...) Two decision/action points stand out as the difference between success or failure in my opinion.

Break the Bank vs. Keep the carbs together

First the tech tips show the bank of carbs still connected together. This is largely due to the way the fuel and carb bowl vent Tees are done. The idea is to not "break the bank apart" unless you really have to. The fuel Tees may leak after you've disturbed their seal and then you would have to deal with another problem. In my case 8 out of the 12 Tees were already leaking so I didn't have the option of leaving the banks together. When I did look inside the Fuel Tee inlets I found a lot of crud even though these carbs came with inline fuel filters. Sure, most people try to blow this stuff out with carb cleaner but then you have soaked the "rubber" parts of the fuel Tees which just can't be good in the long run. I made the decision to break the carb bank apart, address the fuel Tees, and then put the bank back together.

Test for leaks on bike vs bench test

After going through the disassemble/reassembly process I chose to check the carbs for leaks before putting them back on the bike. (When I first got the carb bank I swapped them for the originals, turned on the fuel, and doused the bike with volatile gasoline..Not the way to go here!) This involves setting up a fuel tank and testing the carbs upside down with the float bowls removed to check for needle/seat leaks. Then the bowls were put back on, the carbs set rightside up, and connecting them to that fuel tank again. This tells you if the floats will bind in the down position and therefore leak.

The other owners here provided their much valued input as I myself did the same process you are about to do and are the source of much of what I have just said. If you want more details I can direct you to the threads where there are pics of the process along with the original owners providing the sagely advice which led to my success.

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