Beginner's Restoration Attempts

[EHLawyer]

1979 XS1100 Special. in hibernation, without preparation, for a few years....Got new battery (no maintenance, Power Max GIX50L-BS, $67.00 and no tx/shipping, from ebatteriestogo.com - fits perfectly), so tried to start the beast up. Started up rather quickly, roared well, smoke out of the exhausts, wouldn't idle.......preparing to start by cleaning the carburetors.......once I pulled the fuel tank, noted fuel leaking from the bottom of the air filter.......what would cause that? No obvious leak from the tank...also appears to be slight drip from bottom of carb #1......Any and all help appreciated, and any such help will be rewarded with more questions and more appreciation.

[xssiveone]

noted fuel leaking from the bottom of the air filter....... what would cause that? No obvious leak from the tank...also appears to be slight drip from bottom of carb

This is caused by dirty carbs. When a m/c is stored without prep, as this one was, gas turns to a varnish like substance after a time, causing the float valves (needle and seat) to stick open.

You are on the right track by cleaning the carbs. However, DO NOT SOAK THEM in carb cleaner, unless you first remove the throttle plates and throttle shafts. (more trouble then it's worth) Before attemting to remove the bowl screws and diagphram top covers, get an impact driver like this one: Impact Driver from Harbour Freight. You will think you've found the holy grail after removing stuborn screws/bolts with it. Completely disassemble the carbs one at a time (jets are different from carb to carb on certain models) including the idle mixture screws that the manual will tell you never to touch and all screw-in jets. (Careful with these, brass is very soft) I made up some custom bits for this, just ground them to the correct size. Spray carb cleaner in each passage, allow to soak for 5-10 minutes and then follow by compressed air. (safety glasses are highly recommended) Repeat.. and then repeat once again. Inspect the diaphrams for tears or holes. Tiny tears and holes can be repaired with liquid plastic and reinforced if necessary with a piece of thin latex rubber.

After you've cleaned and reassembled, bench sync them using a metal bread tie or small drill bit. The idea is the get each butterfly opening equal. Then use the idle screw to almost close them. This will bring the carbs in-sync enough to start the engine. Later, you can get a pro sync job, or buy the tool and do it yourself.

Check the Tech Tips on the left side of your screen for hints and tips on various problems and work-arounds that people have found over the years.

And, once you get the carbs sorted out, disassemble and clean/overhaul the petcocks. If the petcocks are working properly, no gas should flow with the engine not running.

[EHLawyer]

Thanks for the advice. After posting my question, did some more searching on the site which confirmed that I am on the right track. I assume that the flooding would also cause smoke from exhaust, gas mixing with oil..........?

Let me ask you this: On the Special, the petcocks have an "off" position, which seems to work as there was no fuel leakage when bike wasn't running, for all this time. Fuel lines run from the petcock to the octopus. Can I just bypass the octopus, so long as I turn the petcocks to off when not running the bike, or is there some other use for that octpus?

Thanks for help and I'll let you know how it turns out.

[xssiveone]

On the Special

DOH!! Missed this part...

Yes, the Special models do have an off postion.. my petcock reference was to the Standard model. I'm not totally familiar with the Specials, but I understand that it is possible to remove the octopus from the system. I belive you will lose the reserve function, but other then that it should work fine.

gas mixing with oil

Thought about this after I made my initial reply. Plan on changing your oil soon. It might not have got that far, but usually if you have gas dripping from the air box, you will have gas mixed with your oil which can lead to bearing damage.

or is there some other use for that octpus?

I'm not sure, but I believe I read of someone launching theirs from a clay pigeon launcher... made for great target practice.

I don't think the octopus is such a bad idea. If it's working properly, you don't have to worry about shutting the fuel off. If it's not working properly, an inexpensive rebuild kit will fix it up.

And in my first reply, I made mention of "liquid plastic".. should have been "liquid rubber". There is an item available that is used for coating tool handles, think it's called Plasti-dip or something similar. It's been used with some success for repairing diaphrams.

[John]

As far as the octopus is concerned, it can be eliminated. I did away with mine years ago. What I did was to cap off the prime port of the petcock....you don't need it, fuel will flow from the run or reserve function. I then connected the two remaing ports together with a length of fuel hose, and it is routed above the air intake boots. Where the hose passes over the 1-2 carbs, I cut it and inserted a T fitting, and attached the 1-2 fuel line into the T fitting. I did the same at the 3-4 carbs. That way I only need to use one petcock to supply the fuel to all the carbs. You will not lose the reserve function, as reserve uses the same port on the petcock as the run position uses. When the fuel light comes on, I open the unused petcock to run to make sure I don't drain one side of the tank before the other. I know some guys are concerned about fuel starvation, but I have never had that problem in all the years of using this set up, and most of my riding is done at 70-80 mph., and I have installed a big bore kit. If you think you need more fuel supply at high speed, then turn on the other petcock. The only drawback is remembering to turn the fuel on and off. Remember, the handle of the petcock will cover the function that is printed on the chrome ring of the petcock...ie, handle down is On, up is Res, forward is Off, and to the rear is Prime.

[EHLawyer]

Carburetors off......first level of success.......gunky as hell, especially the springs on the outside.....WD-40? Carb cleaner? Both?

Also, throttle cable once removed doesn't slide real smoothly in both directions.....I assume it needs lubrication and, if that doesn't work, replace?

I'll keep you all posted

[TopCatGr58]

Carb cleaner first on outside springs, then something a little thicker than WD-40, cause it evaporates. I have used LITHIUM based Spray lube on mine!!

Try carb cleaner in cable, to flush out possible rust particles, then WD-40 to lightly lube and move it up/down/ in/out of sleeve again to further dislodge rust particles, and then try a slightly heavier lube spray. The Lithium doesn't work as well here since it doesn't FLOW, WD-40 may be enough, but if it still feels stiff, then you can get replacements! A lot of the stiffness can come from the BUTTERFLY valves/shaft and once it's cleaned and lubed, it'll turn much easier, less strain on the cable!

Take it slow and easy, and you'll get'er dunn!!!
T.C.

[fabriqueprecis]

carb soaking

I soaked my '80 special carbs for about 4 hours in Berrymans to clean them. THEN I read about the sealed idle mixture screws, which I left alone. THEN I read about removing the throttle shaft and butterfly, which I did not do. SO - should I open up the idle screw seals and see if carb cleaner is in there? If Yamaha says leave them alone, how did the pro mechanics clean these carbs?

I have cleaned lots of carbs with the throttle shafts assembled - never had a problem. Why do you suggest taking the shafts out?

[xssiveone]

Re: carb soaking

Originally posted by fabriqueprecis
I soaked my '80 special carbs for about 4 hours in Berrymans to clean them. THEN I read about the sealed idle mixture screws, which I left alone. THEN I read about removing the throttle shaft and butterfly, which I did not do. SO - should I open up the idle screw seals and see if carb cleaner is in there? If Yamaha says leave them alone, how did the pro mechanics clean these carbs?

I have cleaned lots of carbs with the throttle shafts assembled - never had a problem. Why do you suggest taking the shafts out?

The idle mixture screws are covered to comply with the EPA people. They are pre-set at the factory to provide the least amount of polution output. If you didn't take the screw seals off and the screws out, then there is a good possiblity that your idle circuits might be dirty or plugged. If your m/c is running good, then maybe it's not necessary to take it apart again. Personally, I can't see it being clean with out removing them. And I'm quite certain that pro mechanics don't have any way to clean them other then removing them like us mere mortals.

The reason for not dipping the carbs is that there are throttle shaft seals on either side of the carb to prevent air from entering at that point and leaning out your fuel mixture. Most dip tank carb cleaners are very harsh on rubber and plastic parts. People have either had the seals swell up enough to cause the throttle to be almost imovable, or the seals have been damaged enough to require replacement.

[DeanR]

A couple days ago I sprayed a fair amount of carb cleaner on the outside of carbs with rags underneath to collect runoff (on the bike, just to get them cleaned up a bit) before I read about how strong it is on certain parts. Any chance I hurt anything just spraying down outer areas? Bodies, springs, linkages etc. Also pulled out those plugs. Easy job!

[fabriqueprecis]

Soaked...

Great - throttle shaft seals. Seems like a good idea, actually. Checked the carb and there they are! Not really rubber though, more like a hard plastic. The cleaner didn't SEEM to affect them - yet. Time will tell.

I thought I'd read all the posts and didn't catch this anywhere - I'm trying to search the threads before asking questions that have already been answered.

My idle screws have brass caps that are on (in) pretty good. Have to drill them out?

Glad I read about pod filters here by the way - I'll be keeping my airbox! Thanks.

[TopCatGr58]

Hey Dean,

The spray cleaner isn't as strong as the dip, and it evaporates quickly, so very doubtful that you caused any damage to them!

Glad you were able to get those pilot screw plugs out easily!
T.C.

[xssiveone]

My idle screws have brass caps that are on (in) pretty good. Have to drill them out?

Yes, only way to get them out. They are very thin pieces of metal, so it's necessary to just drill thru them without going too deep and damageing heads of the pilot screws. Once you have the hole drilled, insert a small sheet metal screw a few turns and then pull out both screw and plug with pliers. Should pop right out.