Help Find A Cure for Crazcnuk's bike?

[Crazcnuk]

Took the bike for about a 200km ride, Friday. At 5000rpm steady (speedo cable is broken) on the highway, and about 20km in town, averaged 28mpg (US)

Used about a liter of oil.

Bike ran great at normal cruising speed. Once i was in Edson, though, it started to make a bunch of wierd noises. I checked all the oil levels, all were withing tolerance.

Let it sit while I got some stuff done, then rode it 80kms home, with no noises. Not sure what it was doing.

[Crazcnuk]

I think that changing to the stock Pilots might cure most of the problem.


The whole time, other than at full throttle, the issue has been that the carbs are running excessively rich.

Today I had some freinds follow me while I did some normal crusing around. They observed that when I accelerate I get a large puff of black exhaust, and they can see the black exhaust until I let off the throttle.

A small puff of black is normal, but they said mine was more than normal, and the fact that it blows black continuously on acceleration is another indicator that it is running very rich in the low to mid range.

At this point, I think it's the 45 pilots that are out of place. Since most driving is actually done in the mid range, and economy is never good at wide open throttle, I think changing the pilots back to stock may make a big difference, at least to the economy issue.

I am not sure that my tubes are worn enough to make a difference, I can't actually measure them, and the oval I see may be just an illusion caused by the collar at the top, it's that small. I assume true wear in them would be very visible?

I am not sure if I can get Marvel Mystery oil here, can't recall ever seeing any.

I haven't checked the case vent, but I will. It hasn't given any sign of that, but who knows. My half moons are leaking slightly...

I had no idea there were different size float seats. The ones I put in looked just like the old ones.

I have a stock exhaust system coming. I think I will try and find some 42.5 pilots, and put everything right back to stock, 110's, 42.5s, stock float height, put the stock exhaust on, and go from there. The only unstock thing then would be the K&N filter, but I don't think it will bother the tune.

[Rasputin]

Hey Craz. Marvel Mystery Oil is available here at our NAPA stores. If your local one does not carry it they can get it in for you or I could send you up a bottle. I forget what they charged for it when I bought some a couple weeks ago. It was right beside the seafoam in with the other types of fuel additives etc. Good luck with yer bike

[egsols]

I doubt very much that your float seats would be the wrong size, but one never knows what a PO has done. I didn't know about the different size float seats until I changed mine up using ones for Virago's.

The reason I mentioned the case vent is because of your lack of top end. If the crankcase is building up too much pressure, I think that's where you would notice it the most.

I had a look at a set of tubes yesterday and you're right it's pretty hard to tell if they are worn. I wonder if putting the needle in while having them in front a light would help?

I'm still baffled by your oil consumption, that's a lot of oil to be going through without it showing up as smoke or a puddle on the floor.

With the 110's, the K&N's and your elevation, it might just hit the right mix.

[Crazcnuk]

That's my thought on the subject.

Basically, other than the air filter, the bike will be stock with updated coils, so setting the carbs back to spec should work as designed. At least it's a better starting point.

I will certainly check the vent.

I am just not sure why a PO would have the stock mains and bigger pilots, unless the carbs were on a bike with 4-1's and other mods, that needed a big jet change, then down the years ended up on a stock bike and the owner put the stock jets back in but, like me, never thought to check the pilots.

[3Phase]

Sorry, been busy; mom broke her upper arm falling down her driveway and it's always going to be mom before motorcycles.

A few possibilities and combinations that don't involve money or tearing down and rebuilding your engine to
chase ghosts and create a $5000.00 garage queen:

The vacuum lines to the petcock are collapsing under vacuum when the engine warms up. I bought new O.E.M. vaccum lines from Yamaha but they couldn't handle heat. They were fine when the engine was cold but once the engine warmed up the lines visibly pulsated at idle, then flattened out and closed up at speed. Running on Prime cured it until I could buy some new high-temp orange silicon vacuum lines.

You have the fuel petcock and vacuum advance lines reversed - petcock vacuum line to the #2 carb ported vacuum nipple and the vacuum advance line to the intake boot nipple.

The carb float needle seat inlet screens are plugged or there's a small hamster living in the tank-to-float-bowl-inlet plumbing. You get low speed flow while the hamster can hang on to the bottom of the pipe and swim but lose high speed when his hindquarters get stuck to one of the inlet screens.

Rubber plugs? Are there supposed to be rubber plugs in the carb jet towers but they're missing? Maybe the PO bought the wrong rebuild kit or tried to put in smaller mains with larger pilots and no rubber plugs.

The washers under the main jets are missing.

The jet needle holes in your O.E.M. X2 needle jets/emulsion tubes aren't just a little worn, they look like high-lift big block Mopar camshaft lobes.

One or more slide diaphragms have holes or tears in them. Mine looked fine when I first bought the bike and checked them but by the time I got back from the first test run to Las Vegas, about 500 miles, they had holes. They're patched until I get new ones but they look like pitiful refugees from some sort of tragic shaving incident....

The choke/enricheners are worn out, missing parts, misassembled or misadjusted and not closing.

Using oil - checking the crankcase vent is on my short list of things to do this weekend, too. I check my oil when I buy gasoline and my bike seems to use oil when it feels like it. Most of the time I can ride for hundreds of miles and it won't use any oil at all. Sometimes it uses half a quart or more between fillups. It does not smoke and it does not leak and it does not leave residue on the tailpipe or the rider (me!) and it does not seem to matter what type of riding I do. <scratching head>

Anyway, these are some of the motorcycle-related things I was thinking about over the last couple of days.


Regards,

Scott

[desert1]

air intake

Hows the air intake snorkel look Craz....not being crushed by the seat or plugged with varment crud? Little buggers get everywhere....
Bruce

[Crazcnuk]

Snorkel is good, had it out abut 50 times, all the stuff 3phase listed have been checked, except for the crankcase vent.

Went for another run tonight, 153kms, used 10.1litres of gas which works out to 35.5mpg (US) and 42.7mpg Canadian!

Ran this one mostly at 4500rpm (115kph). with one full throttle race against Derwat.

[olebiker]

You are getting better mileage than I am. I think my tank seal is shot.

[Crazcnuk]

Some friends of mine are going on a road trip leaving this Friday. I would love to go, but I think I need to get some 42.5 pilots in there to test first.

The only other odd thing in my carbs are the 5GLZ18 needles, rather than the 5GL16's that are supposed in there (according to the manuals).

Someone, here, or in another thread said that the XS1100 EPA tested at 47mpg.

I assume that would be US gallons? Any idea which year(s) tested that high.

47mpg (US) would be 53.6mpg(Imp)

47mpg (imp) is 39mpg (us)

[egsols]

I seem to remember reading that the mileage calculations (for highway) are based on a vehicle running on a dyno to simulate 70km(42mph) for 30 minutes and at 68f(20c). Yeah that's how we all drive!

The only other odd thing in my carbs are the 5GLZ18 needles, rather than the 5GL16's that are supposed in there (according to the manuals).

How do you identify the needles?

I have a couple sets of 80/81 carbs...one set was put on my old 79 by a dealer back in '89 has 110 mains and 45 pilots, the other set came off a butchered 81 with 4 into 4's exhaust, running 110 mains and 42.5 pilots. Both sets are running 300 x-2 tubes (same as yours) but both sets are running the fixed needles.

My running 79 has the 5 step needles and the 266 tubes. I'm wondering.... if your carbs were designed to run the 5 step needles.... shouldn't they be matched to the 266 tubes, not the 300's.... or did the PO replace the needles, due to a torn or worn out diaphragm, not realizing a difference between years?

[Crazcnuk]

Yeah, EPA is a bit retarded. I did some checking around and mileage estimates for the XS1100 vary quite a bit.

XS1100E 44.7mpg
XS1100F 47.8mpg
XS1100G 40.3mpg

One site says mileage range 29.5-43.5mpg!

I do think that, as with any high-perf motor, the mileage on these bikes varies, wildly, depending to how you drive.

As for the internal parts, that is the great mystery. According to MikesXS, for the XS650s, 1980 Canadian Model BS34 carbs used 5 step needles 51X11. However, I think that is Mikes numbering system, so I don't know how they compare to what we have.

I bought the tubes that go with those (Y-0), thinking they must go with my needles, but my carbs have the x-2 tubes in them.

The needles have the numbers right on them.

I think all the XS's had 5 step needles until 1980 when the US ones went to fixed needles and capped idle screws.

[psycoreefer]

266 and 300 tubes will both work with the "stepped" needles. How do I know - because 79 specials came with 266 tubes in the center cylinders and 300 tubes on the outer cylinders and Identical stepped needles in all four. I think the 300's have a few more holes in the sides -> leaner mixture, but not by much. I'm running 300 tubes all across now.
I think the only difference between the needles with clips and those without are the extra groves, I believe the taper and such is the same as a stepped needle in the center position.

[3Phase]

Jet Needles

Mark	Slots	Length	Dist.1	Dia 1	Dia2	K1	K2	K3	K4	K5	K6	A1	A2	A3

5GL16	1	51.000	3.000	3.000	0.000	16.800	20.800	34.800	0.000	0.000	0.000	1.45	3.00	7.00 

5GLZ18	5	50.500	3.000	3.000	0.000	16.300	20.300	34.300	0.000	0.000	0.000	1.45	3.00	7.00 

5GZ6	5	52.500	3.000	3.000	0.000	17.200	39.200	0.000	0.000	0.000	0.000	1.45	8.00	0.00 

5IX11	5	51.500	3.000	3.000	0.000	15.500	34.500	0.000	0.000	0.000	0.000	2.15	6.00	0.00 

5IZ7	1	51.800	3.000	3.000	0.000	16.800	34.800	0.000	0.000	0.000	0.000	2.15	8.00    0.00 


1980 SG     = 5GL16 
Crazcnuk    = 5GLZ18 
1978-79 All = 5GZ6 
MikesXS     = 5IX11 
1980 G      = 5IZ7 

The table does list A4 to A6 but they're all 0.00 for these needles. Including them mangled the formatting so I left them out.

Regards,

Scott

[psycoreefer]

Where did you find such a cool table with our needles on it?