carb rebuild

[Mike Swartwood]

I wish to thank everybody for the help I have received. Although I do all my own maintenance I am not a very good mechanic. I just never had a bike this long with this many miles and now have to do what I would call serious maintenance. My 93 now has 100,000 miles on it. With the help from this site I have in the last year fixed the air compressor circuit board, a water and oil leak, replaced the steering head bearings, starter, and clutch plates. Because of a medical condition that will not be resolved till fall I decided to take on my last problems. I have now done a valve adj. and I think I have the starter clutch problem taken care of. The last thing is the carbs. I ordered 4 rebuild kits and took I carb apart and I see where the new gaskets and O-rings go. I have 2 concerns. The kit comes with a new needle valve and seat that I see must be pressed out from the bottom where it looks like a small disc needs to be removed. The kit has no replacement for this so what do I use to fill the hole? I have read about drilling out a disc to get at the idle adj. screws and then screwing them in gently while counting the turns so that you can put them back at the same point. I have also read that they should all be set at 2 turns out. So which setting should I use and the stupid question, where is it on the carb. I also took all 4 vacuum slides out and ordered 4 new ones as 3 had holes and1 had a tear starting at the slide. Again I wish to thank all for the help as I could not afford to have had a shop do all this work and the bike would be what I have seen called a boat anchor.

[lonestarmedic]

Get JIS Phillips screwdrivers!!! And be prepared to vise grip some screw heads and replace. Also take the time to get flat screwdrivers and grind down to fit the jets. Or be prepared to buy jets. I have 4 different ones custom sized.

 

1) The parts to reseal the needle seat are not in a kit. You will need a disc, screen, and o-ring. They are pressed out and in. Using a socket at the outside and a pusher and a small c-clamp or vise. Notice the stake marks around the disc. I would use a dremel or file GENTLY to remove. Now, as long as the original seats are good I would not replace them, just use the new needle. What I do is use a small mirror and light to look in the seat for corrosion and scoring. Then I use a q-tip with carb cleaner and compressed air. Finally a q-tip with a bit of WD-40 for a starting point.

 

2) Idle adjustments screws behind the little brass disc below the big diaphragm cover. Put a stop on the bit so it does not go too far in. Before touching a screwdriver to the idle screws shoot penetrating oil in the cavity and let them sit. Then flush out with brake cleaner. Finally a fresh shot of penetrating oil. THEN go ahead and try to move the screws. Do not just unscrew. Go out a turn and then in a turn to get the oil in the threads. Then in until seated and count the turns if you like. I just set mine 2 turns out then adjust on the bike. I use the old idle-drop method. Along with the premise that too lean will cause the throttle to "hang" when revved up. And the throttle will drop below idle then back up to idle if too rich. All sorts of tricks on the idle enrichment.

 

3) Included vs needed rubber parts. You probably need the rubber jet block plugs. one small and one large per carb. About $6.00 each. Not in kit. The little O-rings next to the diaphragm are not in most kits. The o-ring under the jet block and around the main brass tube may not be in the kit. Main jet access plug o-ring on fuel bowl may not be in kit.

 

4) I just did a complete overhaul of my carbs and finished last week. I replaced all 4 of the idle enrichment valves. Also known as cut off valves. Under a three screw cover on the side. 2 were good and 2 were hard and wrinkled. I used the K&S brand at $20.00 each. Bought them from Dennis Kirk. In stock, decent shipping, and good price. The K&L are also good, just about $10.00 more money.

 

5) Pull the idle jet and emulsion tube from the jet block and clean like crazy. That itty - bitty idle jet is a pain to clean out.

 

Any questions do not hesitate to ask. I am not an expert on the carbs, but the experience is fresh in my mind.

 

JB

[lonestarmedic]

Get JIS Phillips screwdrivers!!! And be prepared to vise grip some screw heads and replace. Also take the time to get flat screwdrivers and grind down to fit the jets. Or be prepared to buy jets. I have 4 different ones custom sized.

 

1) The parts to reseal the needle seat are not in a kit. You will need a disc, screen, and o-ring. They are pressed out and in. Using a socket at the outside and a pusher and a small c-clamp or vise. Notice the stake marks around the disc. I would use a dremel or file GENTLY to remove. Now, as long as the original seats are good I would not replace them, just use the new needle. What I do is use a small mirror and light to look in the seat for corrosion and scoring. Then I use a q-tip with carb cleaner and compressed air. Finally a q-tip with a bit of WD-40 for a starting point.

 

2) Idle adjustments screws behind the little brass disc below the big diaphragm cover. Put a stop on the bit so it does not go too far in. Before touching a screwdriver to the idle screws shoot penetrating oil in the cavity and let them sit. Then flush out with brake cleaner. Finally a fresh shot of penetrating oil. THEN go ahead and try to move the screws. Do not just unscrew. Go out a turn and then in a turn to get the oil in the threads. Then in until seated and count the turns if you like. I just set mine 2 turns out then adjust on the bike. I use the old idle-drop method. Along with the premise that too lean will cause the throttle to "hang" when revved up. And the throttle will drop below idle then back up to idle if too rich. All sorts of tricks on the idle enrichment.

 

3) Included vs needed rubber parts. You probably need the rubber jet block plugs. one small and one large per carb. About $6.00 each. Not in kit. The little O-rings next to the diaphragm are not in most kits. The o-ring under the jet block and around the main brass tube may not be in the kit. Main jet access plug o-ring on fuel bowl may not be in kit.

 

4) I just did a complete overhaul of my carbs and finished last week. I replaced all 4 of the idle enrichment valves. Also known as cut off valves. Under a three screw cover on the side. 2 were good and 2 were hard and wrinkled. I used the K&S brand at $20.00 each. Bought them from Dennis Kirk. In stock, decent shipping, and good price. The K&L are also good, just about $10.00 more money.

 

5) Pull the idle jet and emulsion tube from the jet block and clean like crazy. That itty - bitty idle jet is a pain to clean out.

 

Any questions do not hesitate to ask. I am not an expert on the carbs, but the experience is fresh in my mind.

 

JB

[frankd]

You can buy a decent JIS phillips screwdriver at Harbor Freight for about $2.00. You'll be amazed at how much better the JIS phillips works as compared to the U.S. version on metric screws.

[Mike Swartwood]

Thank you. I think I had a problem finding the idle adj. screw is because there is no plug covering it up on any of my carbs. The only time the bike was at the dealer was after the original break in to check the oil and make sure it was running correctly. It was running fine when I took it back so I do not think they removed them. My guess is they were never installed. Has anybody heard of this? I will start cleaning everything up and rebuild the rest of the carbs while I wait for the new diaphragms. Thanks again

[Mike Swartwood]

Thank you I will do that