Bring a 1979 xs1100 back to life

[rogueinla]

Hi, new here, so if these sound like stupid questions, bear with me.

I just bought a 1979 xs1100, mileage unknown (broken speedo), the guy I got it from was pretty clueless about the bike, he'd shoved it in his garage 3 years ago, but, it's complete, I had some xs1100s (6 of 'em) back in the 80s, but I never really got into them, I got them as a package deal, all ran, but only 2 had good trans, I only played with them enough to be impressed with the power, then sold them and got a Venture Royale....

I got it home, cleaned the tank of varnish, took off the carbs, took them apart, went over them with carb cleaner, put them back together, I counted the turns on the jets (it'd run when he parked it) so they're roughly back where they should be.

I've put new plugs in it, NGK BP6ES, that's what was in it, or is there a better plug? (just planning on riding around town, some runs to the beach (50 miles) not planning on racing it... (yeah right, all that power is a temptation).

Checked the oil thru the sight gauge, it looked ok, so I tried to fire it up, it's got spark, the starter sounds like hell, and disengages a lot, so that's on the list, it fires with starting fluid, but won't run.

After running for about 10 seconds, it died, I heard a gurgling, and oil poured out the vent tube(?) behind the gearbox. Sooooo...
I drained what I hope is the oil, it's the plug that is accessible from the front of the bike, right behind what is the filter? I got about 2 gallons of this milky black fluid, feels like oil with a ton of STP in it, or maybe it's synthetic? I've never used it, so I don't know what it feels like. If this is the oil, I'm thinking it was a lil overfull, the previous owner mentioned it leaked out the shifter seal. Or, did I drain the wrong plug? I haven't taken the filter off yet. What's a good oil to run in it?

I was going to get a clymers for it, but from the thread here, I don't know if that's a good idea, can someone recommend a good manual?

I've put new plugs in it, NGK BP6ES, that's what was in it, or is there a better plug? (just planning on riding around town, some runs to the beach (50 miles) not planning on racing it... (yeah right, all that power is a temptation).

What else would anyone suggest be done before I fire this thing up? I'm getting gas to the carbs, pulled the plugs from the bowls, and all have good gas rignt now. Also, did Yamaha do a real crappy job on the frame welds, or do the ugly welds above the rear shocks mean this thing's been broke and rewelded?

I'm thinking of draining the gearbox (if I didn't do that already by taking out the wrong plug). What's good to put in there?

Any tips or information would be welcomed, I haven't worked on bikes in about 10 years, and I just want to make sure I'm not missing anything.

I think I can handle the XS, the last 2 bikes I had were the above mentioned 1990 Venture Royale, and a 1993 Harley Ultra Classic Electra Glide (never do that again, unless I want a lawn ornament)

Thanks

Randy

[DiverRay]

Welcome to the club!
The clymers is better than nothing, so I would get one. The drain plug just behind the oil filter is for the engine/trans oil. From what you said, I would suspect plenty of water in it. Change the filter with the oil, and just use Castrol 20/50 for now. It should take just under 4 quarts of oil with the filter.
The spark plugs are correct, but I think you need to clean the carbs once again. You NEED to pull ALL of the jets, and make sure all the passages are clean. you can do a search on "carbs", or check the "tech tips" on the left for more information.
The middle and final drives take 90w gear oil. You should have the plastic "gauge" from Yamaha for checking them. The final drive drain and fill is easy to find, but the middle gear is hidden up under the rear of the engine. The book will help you find the 19mm drain plug for the middle gear. I would run a little "brake kleen" into the middle and final gear boxes to help clean.
Ray

[planedick]

Gear oil...

Mentioned before that 90 WT gear oil for the final drives. Actually the proper oil is HYPOID gear oil, there is a great deal of difference and regular gear oil will not protect the gear train.

[TopCatGr58]

Hey Randy,

Also, welcome to the wacky world of Xcessives!! Aside from the Tech Tips links in the left column, you will also need/want to go to the MAIN FORUM page, scroll down and peruse the tips there, many are NOT linked from the links on the left!!

Like DiverRay said, just pulling the bowls off and spritzing around is no where near effective enough. The Pilot circuits are very prone to clogging due to gummed gas, etc., lots of little aeration ports in the pilot jets, the MAIN jet Nozzle/emulsion tube that slides up thru the middle of the carb body once you remove the main jet, and the top caps, the rubber vacuum diaphragms and slides and needles. There is also a small jet in the little hole in the float bowl that feeds the CHOKE/Fuel enrichener circuit, and it also easily clogs, may need to use a piece of wire and carb cleaner to get it to spray thru!

The rubber mounts for the carbs can form leaks, causing a problem being able to suck the fuel into the engine. The vacuum port caps on the intakes can also harden and leak!

If you'll go to the LINKS section on the MAIN FORUM PAGE, look for Manual for 81SH/H, it'll show you where the various oil containers, plugs, and levels, etc. for them are. It's in PDF format, about 6MB, complete with photos and such, so even though it isn't a direct version of your machine, the engine is pretty much the same!!

Also the fuse blocks are notorious for just falling apart, so you may want to replace and rewire it with a solid fuse type, again, see the tech tips, and I know where you can get a replacement fairly cheap!!

Please take some time, read thru the tech tips, repairs, maintainance, mods, and even MISC, and then do some searches in the tech forum, use several words together to help narrow the response, you'll probably find many of your questions have already been asked and answered there!! Good Luck!

[randy]

Randy,

Everything T.C. said AND, give us your location in your profile, you may find local hands-on help if things get hairy! Good luck with your project.

[rogueinla]

Thanks for all the information, I changed the oil & filter, using the Castrol 20/50 you recommended, gawd was the filter filthy. I guess I wasn't clear about the carbs, I took them off the bike, disassembled them, as far as anything and everything I could unscrew, unclip, unpin, and put 'em back together. If it still doesn't start, I may do it again tonight, nothing like curling up in front of the TV with a buncha tools and some carb cleaner.

Thanks again

Randy

[rogueinla]

Compression, going R to L seated on the bike, is 75, 85, 75, 80, that good or bad? While cranking it over, I held my hand over the carbs, #1 has good suction, poured gas all over my hand, #2, not quite as good, but spit out gas, # 3 & 4, almost no suction, no gas, this say anything about the state of the motor? Oh yeah, it starts if I hold my hand over carb 2, and actually revs and runs for about a minute before dying, sounds semi healthy

[TopCatGr58]

Hey Randy,

THose Comp values are bad, but not sure if you did it correctly. Best to be done with warm engine, but hard to do when engine NOT running! Also, did you have the Throttle WIDE OPEN? If not, then you were not getting proper unrestricted air flow into the cylinders! Also, were you using a good battery to spin the motor quickly? Try again with WOT, all plugs out. Then record values, then squirt a touch of oil into the spark plug holes, and repeat.

IF increases, then rings are worn, if doesn't increase, then could have burned valves. Stock new at sea level is 142 + 14 psi. Hopefully you'll get values closer to 110 or more, and within 10% of each other. After it's running and gets a few hundred miles on it, the rings can reseat and the comps can actually improve and increase!

Btw, #1 cylinder is on left as seated.
T.C.

[wingnut]

Run it a while

Rogueinla, Welcome! When I got mine a year ago I did my compression check like you described. Numbers you have are low by the book but they are within 10% of each other. Thats a realy good thing as it shows you that all are in the same condition. Also I received about the same numbers. After I got the carbs right and the engine running as smoothly as I could I rode the bike for a while. I found the numbers came up to spec. The rings just needed to re-seat after sitting static for so long. There also my be some junk on the valve seats that needs to burn away before you get the numbers you are looking for. As TC says, you need a warm engine and wide open throttles to get the book numbers. Work on getting the carbs right and run it for a while. Then try again if it does not smooth out. This is all predacated on it sounding like nothing is banging around in there If they are still low after all that at least you know the crabs are right before you start the cylinder work.

[oseaghdha]

Crankcase

Welcome rogueinla,
Couple things you should do before trying to run it.
ATF(Dextron) is loaded with detergent. Put a couple of quarts in with some cheap oil. Add some through the spark plug holes and let it sit overnight. Cycle the engine with the starter. Seafoam also is said to work well at cleaning the crankcase and rings. Once you get it running, dump it and replace the oil and filter. I changed mine out twice while reviving my SF. Oil is still nice and clean after about 1000 miles.

You will read about "Triple Cleaning" the carbs. Three times seems to be be the majic number. Some kind of XS voodoo, I guess.

Add inline filters to prevent or retard tank garbage from gumming up the carbs.

Absolutely change the gearbox front and rear.

Good Luck

[skids]

While all of the things that were recommended above could be good, you should be aware that a pressure gage can be way off. There may be a way to check it againt compressed air with another gage if you have the fittings. This is just one more reason to look at differences between the readings.

[planedick]

Not far at all....

I'm not that far away from you at all and I'm always looking for an excuse for a ride. I could easily be induced to ride up there and look at another XS.

[rogueinla]

Thanks for all the info, I took the carbs off again, dissasembled and cleaned again, idiotically broke a float pin post off in one carb, arrrgggghhh... however, it's not quite half broke, and the floast stays in place, so I'm going to use it to fire up the bike until I get another carb body, now the problem is, the bike cranks, tries to fire, but as soon as it pops, the starter kicks out, so looks like I replace the starter before I do anything else

Plane, I greatly appreciate the offer, but, in it's current state with the starter, it'd be a wasted effort. I'm going to look at a parts bike today, so if I get a starter and a carb body, if you'd like to come to N. Hollywood and look at the beast, email me and I'll send you directions and a phone #.

Frustrating devils, ain't they?

Randy

[trbig]

Rogue... not trying to be a smart @$$, but did you clean the jet that is actually in the BOWL of the carbs? It is along the edge of the bowl and it is the one that is most used in STARTING. It's way down in there and kind of hard to see without a light. That small brass tube from your carb goes down into it. Carb cleaner shot into that jet will shoot right back at you from the bottom of the bowl if it's clean... so watch your eyes AND the texture and paint on your ceiling while watching the TV!

Tod

[TopCatGr58]

Originally posted by rogueinla
Thanks for all the info, I took the carbs off again, dissasembled and cleaned again, idiotically broke a float pin post off in one carb, arrrgggghhh... however, it's not quite half broke, and the floast stays in place, so I'm going to use it to fire up the bike until I get another carb body, now the problem is, the bike cranks, tries to fire, but as soon as it pops, the starter kicks out, so looks like I replace the starter before I do anything else

Frustrating devils, ain't they?

Randy

Randy, the Starter does NOT kick in and out like an automotive, there is no sliding gear on a shaft actuated by a solenoid. The motor spins a gear that spins another gear mounted around another shaft that drives the crank. There are 3 pinch rollers that slide down onto the second shaft and grab it like a pipe wrench when the starter motor is turning it, but once the motor catches, those pinch rollers are flung outward releasing their grip. Sounds like your starter is working fine, but you don't have enough fuel, or a good flow of fuel to keep the engine lit. You had said that it ran for 10 seconds using starter fluid/spray! But having old gummy oil could interfere with the ability of the pinch rollers to grab the shaft, has been reported some slipping can occur with synthetic, as well as a high viscosity and very cold temps!

As for your carb float post....BTDT as many here have. JB Weld will fix it just fine, and I think there is a tech tip on repairing a broken float post. So...don't count your carb body a lost cause yet!!!

Tod, if you'll read the second paragraph in my first reply, I mentioned the float bowl jet, and how to clean it with a wire!!

It's difficult to check for vacuum leaks when the engine won't stay running! When you have the carbs off, you might want to also remove the intakes, check the engine mating surface, the rubber can age and crack creating vacuum leaks, not to mention the outside cracks...but those are usually cosmetic, since the manifolds are dual layered. You can remove the dryrotted rubber from the mating surface and use a gasket and some Yamabond type sealant to get them to be air tight when you put them back on! Remember, check the rubber plugs on the vacuum ports...if dry, replace with some from auto store! Keep at it!!

Once you do get it to run for more than a minute, then spritz some water on the headers and see if you have any cold pipes, depending on which ones will provide more diagnostic info for you. Write back here, and we'll help decipher the info!
T.C.