Barn find freebie 1978 xs1100E

[donebysunday]

Meeting

BOB and his wonderful family was a pleasure !
When you were first warming up the engine and I saw that wiff of blue smoke I thought valve seals. On the other hand I overfilled my brand new 79 SF and it did the same.
Must get together for another longer ride and check out progress on both of our bikes.
Maybe we can get dbShea to come along, one of you guys can be leader, these days I follow. Don };-)

A big thanks to donebysunday for stopping over and then taking a ride with me as I gave the xs an initial run. I was able to get the idle sorted and during the ride the cycle felt great and didn't have any issues. When I parked after the ride I used the side kickstand and saw oil seeping out of the airbox at the seal line between the top and bottom half. I didn't have any gas or carb float issues until now but may have overfilled the crankcase when I changed the oil. I'll investigate further but for now I am quite happy to have it on the road again.

Thanks,
Bob

[Eastcoaster]

oil

check that crankcase I have filled mine with leaking fuel and spewed oil right up the air box through the breather like I hit an oil geyser

[olinrj]

A big thanks to donebysunday for stopping over and then taking a ride with me as I gave the xs an initial run. I was able to get the idle sorted and during the ride the cycle felt great and didn't have any issues. When I parked after the ride I used the side kickstand and saw oil seeping out of the airbox at the seal line between the top and bottom half. I didn't have any gas or carb float issues until now but may have overfilled the crankcase when I changed the oil. I'll investigate further but for now I am quite happy to have it on the road again.

Thanks,
Bob

[olinrj]

Skids,
I definitely realized that after the fact! Unfortunately, I couldn't reach the idle screw without taking one of the petcock vacuum lines off, so I had to shut off the xs every time I adjusted the idle. Looking back now I suppose I could just turn the petcock to prime and cap the vacuum line. I'll give that a whirl and report back.

Thanks,
Bob

[skids]

You definitely have to wait for the engine to reach equilibrium prior to making changes! (As long as the engine keeps running).

[olinrj]

T.C.
Thanks for the troubleshooting tips. There is about a quarter inch of throttle turn before the cable engages. I did verify the carbs were bench synched. All had the same exposure at the pilot jet port holes, but I cannot remember if one was fully exposed or not. The vacuum advance hose is indeed plugged into the correct nipple on the number 2 carb body. The caps and vacuum lines all are attached and secure but I didn't vapor test for leaks with propane or other gas. I am thinking that I was too overzealous in my initial idle setting and didn't wait for the engine to properly warm up before taking it off choke. I'll reser the idle control know and go from there. Thanks again,
Bob

[TopCatGr58]

Hey Olin,

Okay, throttle cable not stuck....but ensured that there is actual a 1/4" slack in the throttle cable at the handlebar..there's an adjustment possible there!

Turn the main central idle screw back/CCW until the screw isn't hitting the setting plate.

Also, ensure that you don't have any vacuum leaks with the intake port synch caps/plugs.

Did you BENCH SYNCH the carbs/butterflies?? The carbs are out of balance and that causes the runaway idle. There is a tech tip about using a bread stick tie, but that's still not as accurate. Instead, use the 3 pilot jet port holes in the top of the carb throat engine side, the butterfly will partially cover one when almost completely closed, and set the others to the same position, and this will get them close enough to not have the run away idle, but then you will still want and need to vacuum synch them...but you should be able to get a decent test drive/ride with just a bench synch.

Also, ensure that the vacuum advance unit is plugged into the #2 carb metered port on the carb body, NOT the intake carb mount/port!

Then once started/warmed up and not running away with the idle....you can adjust the main idle screw to set it to around 1100 rpm.

T.C.

[olinrj]

I repaired both fuel supply tees and last night got the carbs on and everything back together. Today I put a couple gallons in the tank and started it up. Initial startup was rough and it didn't want to idle without the choke on. I adjusted the idle a bit at a time until it would idle without feathering the throttle. I decided to try to take it around the block and that's where it got interesting. While off the throttle but in gear the bike seemed to want to accelerate. I took this initially as me not being used to the cycle. When I began to slow down for a stop sign I clutched in and the motor raced to around 6k rpms. I thought I lost the throttle cable. I shut off the bike and once stopped verified that the cable was intact. I tried to start it again and it once again surged to about 6k rpms. Because I was a couple blocks away I decided to feather the clutch to get going and try to make it home. Once in gear, the rpms dropped to match the cycle speed, so it wasn't a runaway. It's in the garage ready for a little more attention.
Does anyone have any thoughts on this? My initial theory is the idle screw is set too high and now that the engine warmed up and got put under load things are freeing up and acting like they should and my initial adjustment to get it going then is way off for what it needs now. I work tonight but will try to get a few minutes in tomorrow if possible. I'm so close to getting a real ride in that I can taste it!

Thanks,
Bob

[olinrj]

Thanks Mike. Today I stopped at harbor freight and picked up the o-ring assortment. Tomorrow I hope to pull the carbs and get the tees repaired and reassemble everything. I'm still planning to put some miles on the xs this year, I just don't know if it will happen in September.

Thanks,
Bob

[MPittma100]

There is an alternative to the tee o ring fix. There are aftermarket brass tees available too. There are 2 types - one tee is for the bowl vents, the other is for fuel. Basically the same tee but 2 different widths. Depends on year model carbs you have.

Problem is that they are not cheap. Some guys are asking almost the same amount for used OEM tees?

http://www.ebay.com/sch/i.html?_from...l+tee&_sacat=0

http://www.ebay.com/itm/Yamaha-1J7-1...RVDIcc&vxp=mtr

3H3-14988-00-00, 2H7-14988-00-00, 1J7-14988-00-00 are some OEM part numbers.

[olinrj]

The engine runs! Everything sounded good to the ear during the initial run but I have a couple of items to follow up on- first, the choke doesn't stay in positionn it slides back to off. I had to hold it with my hand during starting. Second, fuel was leaking between the number one and two carbs. There was no indication ofan issue while it ran. The first thing I'll do is use the o-ring fix on the tee as the rubber showed visual deterioration when I cleaned the carbs. Hopefully this sorts out the leak, if not I'll just go down the list.

Here's a closer look as my test tank. Just an old one probably from a snowblower with a shut-off, filter and tee. I do need to change the mount, probably going to fab a clamp-post I can attach to the handlebars.



Thanks,
Bob

[olinrj]

Carbs and airbox are back on. I have the test tank nearly set up but had to quit to complete domestic duties. All in all a good day as I don't usually get much of anything done on my first weekend day off. It's a unique situation, 4 days on, 4 days off, and I work nights. Having 2 young boys, 5 and 2, I can't keep a night schedule during my weekends or I'd miss out on too much of their lives. So I switch back and forth every 4 days, usually getting a nap but most often it ends up being a 30 to 36 hour day. I know many people work swing shifts or extended shifts but I'm now experiencing it and it's a unique way to earn a living.
Sorry for the rambling but I felt it important to include in this thread as it may help explain the starts and stops in progress as well as the random posting times of my posts.

Thanks again for everyone who has stopped in to lend advice or just followed along.
Bob

[olinrj]

Mike,
Thanks for the confirmation of the jets. Because I haven't ridden the xs more than up the block the day I got it, and the previous owner said it ran great when he rode it regularly, I'm going to leave well enough alone unless something comes up during the final tuning.

Thanks,
Bob

[MPittma100]

After another break from the bike I have been able to put some time in the garage and got quite a bit done. I tweaked the valve shim tool to fit the head and took measurements and verified what shims I have :
Intake
1 .003 Shim 260
2 .004 shim 255
3 .004. Shim 260
4 .005. Shim 260

Exhaust
1 .006 shim 290
2 .008 shim 285
3 .008 shim 290
4 .007 shim 285

Based on this I'll need to change at least 6 shims to get everything back into spec. Some advice I am seeking is whether to go to the high side of the spec or just get it into the range. Any thoughts are appreciated.

I was able to replace the cam chain tensioner with the automatic tensioner and all went well.

The carbs came off and I started digging into them. Two had fuel staining on the outside of the float bowl and each one had sediment in the bowls. I cleared all the jets and noted what size was for each. The mains are 137.5, the pilots are 42.5 and what I believe are the air pilots, at 8 o'clock on the airbox side are 210. I don't know how the change in both pilots will affect performance but there must have been a reason for replacing the stock sizes. Again, any thoughts are welcome.

I hope to continue progress once my weekend starts on Wednesday and will let you know how it goes. Thanks for stopping in on my thread/diary.
Bob

Every stock E carburetor I have rebuilt had 45 pilots and 210 air jets. None of the manuals specify those sizes, but have been in every E? I've seen this in 7 E carb sets.

[olinrj]

The carb boots are back on and I cleaned up a little of the oil and grime on the back of the engine while I had the room. Tomorrow morning is the start of the weekend and I plan on getting the carbs back on, charging the battery and giving the engine a try.