My first XS 1100...running rich?

[Travis75az]

Hello to all,

I'm a newbie to the XS11 and motorcycles in general. I raced moto for several years as a kid and had a bike in college, but I haven't messed with a motorcycle in 10 years. I live in AZ and I just bought a 81 XS 1100. The VIN is only 9 digits so I'm having a hard time figuring out the exact model (Title says Model: X1S).

http://i1087.photobucket.com/albums/...5az/XS11-2.jpg

I bought the bike as a roller and paid to have a guy wire it. I also had a local shop get it running and mechanically sound. (I know I should be doing the work on this bike, but I've got enough knowledge to be dangerous - truthfully I'd probably end up catching the thing on fire).

Recent work to get it running:
1. Carb rebuild kit
2. Intake Boot set
3. Slide Diaphrgams
4. 47.5 pilot jets
5. Compression test (130/130/125/145psi)
6. All fluids
7. New Battery
8. Carb sync / tune

I've been riding it around for a couple days and everything seems to work well except for a couple issues. I'm hoping you all can point out and give me some direction. You all are infinitely more knowlegable than I am!

AZ unfortunately requires emissions. I took the bike down and it was hot - 40 minute ride in 90+ temps. I have K&N filter pods and straight pipes 2 into 1 (it's loud and yes, it's awesome).

Test: Idle for 30 seconds and rev to 2400rpm for 30sec and back down to idle. **Please note - I don't have a tach so I was just guessing on rpm (should I have added more throttle?)

Hydrocarbons: 791 out of 1800 = Pass
Carbon Monoxide: 11.25 out of 5.50 = Fail

I used a 91 octane, nothing more.

The data looks like it's running rich? The bike smells like raw fuel even after sitting overnight. Original Pilot Jet is 42.5 (per CLYMER manual). With the K&N filters, modified exhaust and Phoenix altitude (or lack there of) why would the shop select the 47.5 jet?

Am I right/wrong/suggestions?

I already tried to get out of the emissions testing by registering in another county, but that's not going to work. I also read a few posts on adding Methanol to the fuel, but I don't think it will bring the CO down enough to pass. I just want to get the thing plated and ride!

Thanks in advance!

[motoman]

Leave in the stock pilots.......... stock mains for 81Special are 110's(if it still has the 81 carbs on it). May wanna have 112.5's or 115's with the pods. With the straight pipes, it's never gonna tune totally correct or run good in the upper rpm ranges. BTW, some nice ridin' weather there now......

[natemoen]

Give us thebfirst half of the vin and we can tell you what year/model it is. I agree, put the original pilots back in there, could even be the wrong style pilot jets altogether, the kits often di have the wrong pilots.

[DGXSER]

Whats left of the stock bike would suggest it was a special, but it is all guess work at this point, and really of no importance to your issue.

With the K&N Individual filters/POD filters, and that exhaust system, it will prbably run like crap but may get you to the registration with stock jetting. Like Moto suggested, the carbs are interchangable from one year to another, so it is hard to be sure what year carbs you have.

Stock jetting for the 81s is 110 across with 42.5 pilot jets, floats set at 23 mm +/- .5 mm. But with the redical pipes and the filters, I am guessing it will barely run with stock jetting.

[XS1100_OEM4ME]

1980 Special?

The forks look like a "Special", the strait spoke front wheel with slotted rotors looks to be 1980 as well as the grove in the stator cover looks 1980, so my best guess is it started as a 1980 XS1100 Special or 1980 MNS

[cywelchjr]

Those readings definitely show it to be rich. Since the pilot jet affects both low and high speed, going back to the stock jets and properly tuning the carbs may well make it pass, but that is STILL going to be very hard if impossible with straight pipes as these engines do NOT tune well (actually hardly at all) with straight pipes, so you may need to get a baffle put into them at least, if not an actual muffler put on to provide the back pressure the engine needs to tune properly. But once you get the back pressure the engine wants, it should then be pretty easy to get it tuned well enough to pass the test, as when running right, these engines run very well and clean.

[Travis75az]

Thanks to everyone for the very informative responses!

The first part of the VIN: 4R000

I let the bike warm up and did a few rips up and down the street. I pulled the plug and this is what it looked like:

It was about as black as midnight but no oil.

I'll put the original 42.5 pilot jets back and try out the 112.5 mains. Does anyone know of a link to a baffle I can install in the pipe? Do shops do this?

I'm sorry for my ignorance, but I'm learning a ton and enjoying every minute of it!

[Travis75az]

Here's a pic of one of the carbs. Is there any other serial or indentification on the carb that would determine the model Mikuni?


Another pic of the bike:

[petejw]

hi Travis75az,

ur definately running rich, as the boys previously
stated drop ur pilots down to 42.5 and u should be sweet
with 112.5 or 115 main jets if u have them on hand,
with ur plugs if u do a search for soda blaster,
the bi carb will clean those plugs up nicely, if u cant
clean them replace them with new ones.


looks like u have a,

1981 XS1100SH 4R0-000101 Black Blue, Cardinal Red

[Travis75az]

Well I talked to the shop that did the "work" on my bike and they were extremely hesitant to reinstall the original Pilot jets. They said "we couldn't even get it to run with the original jets, it probably won't even idle. You've got modifications like straight pipes and filter pods and the bike just doesn't want to run." Please note that these guys are a reputable shop, but they're primarily a two-stroke moto shop.

So now I'm in a delima: They said they'd install the original jets and "do their best" to get it running; or I could just take it to another shop and see what they can do?

From what it sounds like, I wouldn't be able to lean it out enough with the A/F screws with the current 47.5 jetting to pass emissions.....

Thoughts?

[cywelchjr]

You probably won't be able to lean it out enough with the straight pipes to pass emissions. You are very likely going to need to either put a muffler on it (you might be able to put a harley muffler on it) or something similar that you might be able to get from a harley shop, which will actually likely increase performance, or find some way to put baffles in it, the muffler is likely to be FAR easier to do, but will require some fabrication work to make it work. I don't know how things work in Az, but here in Ca, any vehicle that has to pass a emissions test when sold must be made to pass by the seller unless sold for parts, if it's sold as a driveable vehicle, even if "as is" the seller STILL is responsible for making it pass.

[TopCatGr58]

No aspersions to the shop that worked on it, but as stated, the plugs are showing it too rich, but just running it up and down the street and then pulling the plugs is not quite the right technique to check the plug color. A proper throttle chop requires normal operating temps, then sustained under load run for 30seconds to a minute..preferrably up a slight hill, getting into the mains...~4-5k rpm, then pulling the clutch, hit the kill button, coast to a stop, and then pull the plugs. This will give you the proper reading of the MAINS. So..the plug color you're seeing is more indicative of reading the pilots. There are two styles of Pilots that will fit into these carbs, the VM style and the BS style. The VM is also known to cause excessive richness, and it's easy to get them mixed up. The VM has the metering orifice near the threads, the BS has the metering as the pointy tip. Here's a diagram from MikesXS.net that illustrates that:


Folks have welded a washer on a bolt into the end of the straight pipes, where the washer/bolt can swivel so you can "TUNE" it to try to get some semblence of backpressure.

Lastly, the 91 octane fuel actually burns slower and not as completely as the lower grade stuff, so put in some regular gas as well to help provide more complete combustion for the emissions test. Also, if the engine is NOT pinging then continue to run the lower grade fuel, premium is not required unless you have a pinging/preignition condition, a recent octane discussion cleared up the misconceptions of early octane ratings in the late 70's vs. modern octane ratings.

T.C.