Tribute to my Dad bike

[gene]

Hey Guys, I bought an 1981 XS1100 Special. Got it cheap, but wow this is going to test how much my dad taught me. I pulled out the air box and carb this morning. The jets I have are 110 main and 42.5 pilot jet. If I use the standard scheme, I will only end up with a 117.5 main. Did they tone these down that much in 81'?

With a 4 into 1 exhaust and drilled air box with K & N the rest are using 145 main and 45 pilot.

I just bought the intake boots on line, but I'm waiting to order the jets.

Also, my dad ran velocity stacks and removed the air box. Anything wrong with that? This bike is going to be tough to keep stock.

Tank has 3 dents who would you guy's recommend I send this thing to?

Thanks for your help in advance.

Gene Jr

[DGXSER]

Congrats and good luck

Hey Gene, awsome you are oding this XS11 tribute to your dad! Yes, the stock jets in the 81 carbs are 42.5 pilots and 110 mains. The mains are smaller due to the unshielding of the pilot jets form the earlier carbs. So the main no longer needs to be lartge enough for both fuel sources.

There is a tech tip on jetting sizes. You may have found it, the size changes it recommends should be from the 110 and 42.5 sizes. You may also want to note they chnaged the float setting down to 23 +/- 0.5 mm. Lots of folks here run the "pod" filters you mentioned.

[gene]

Makes sense now. Thanks for connecting the dots. Looks like 117.5 main and 45 pilot. Might have to round up to 120 on the main.

Gene Jr

[XSPastor]

YMMV but here's my setup...

I've got an 81 special and, as you can see from my signature, I'm running 120 mains (rounded up on TC's advice) and stock pilot jets with a 4 to 1 and a drilled air box with a K&N. It runs well for me. Nice plug color, plenty of power.

[81xsproject]

I don't want to step on toes, but testing with my O2 sensor showed 120's to be quite a bit too big especially with 45 pilots. Even with my pods and a large 4-1, 117.5 with 45 pilots is as rich as is desirable for max power. I also live at sea level.

[XSPastor]

No toes stepped on here! Just reporting what works for me. I'd rather error on the side of rich as long as the plug color is good and it runs well.

[Crazcnuk]

I want max power and 45+mpg!

I have 4:2 turnouts and K&N element with 115's and 45 pilots. Runs very strong, but have not ran enough gas through it to check mileage.

For some reason, our Canadian models appear to come standard with 45 pilots and 110 mains, and wierd needles and needle valves.

[TopCatGr58]

Hey Gene,

Just straight velocity stacks alone are not good, the air needs to be filtered! Check out the tech tips, MODS section, carbs, you'll find a thread about different ways of putting on Indy filters so you can have the velocity stack effect, it's suggested to help straighten the air flow after it gets thru the filter vs. just the filters so close to the inlets, and some cheap Cone filters have a prominent mounting lip that can obstruct the air flow to the small jets and ports around the edge of the inlet bell, so the velocity stacks help in that aspect as well!
T.C.

PS, I'm running 117.5's and 42.5's, sea level, Indy filters and 4-1 pipes, but also little big bore kit. My dyno test a few years ago showed that I could possibly go up to 120's, but haven't done it yet, decent plug color, performance and mileage...only low 30's, but I'm heavy wristed!

[gene]

Hey Gene,

Just straight velocity stacks alone are not good, the air needs to be filtered!
T.C.

PS, I'm running 117.5's and 42.5's, sea level, Indy filters and 4-1 pipes, but also little big bore kit. My dyno test a few years ago showed that I could possibly go up to 120's, but haven't done it yet, decent plug color, performance and mileage...only low 30's, but I'm heavy wristed!

I was thinking the same thing about the air. In Florida the air was cleaner.

Thanks

[gene]

Alot of great advice. Sounds like I should justchange the mains first. I will play around with it and let you all know the results I get. Jets are cheap.

Thanks Again Everyone

[gene]

Hey Guy's I found some photos of my Dad's xs1100. Check it out.

[DGXSER]

Very nice lookin 80 special!! Little bit of customizing to. What did he do for air filter(s)?

[fredintoon]

I want max power and 45+mpg!

Hi Craz,
as they say in Yorkshire of someone who asks for things they can't have:-
"Then want shall be thy master."

[gene]

Very nice lookin 80 special!! Little bit of customizing to. What did he do for air filter(s)?

In South Florida the air is pretty clean as long as you stay away from the beach. He ran without filters just stacks for about 20 years. He used to little plastic bags when he cleaned it.

Out here is California I will definitely run filters.

[gene]

All right I broke down today and bought the big bore kit. APE is grinding the cams to go with the kit. More money than I planned on spending. How many times have you heard that?

Chrome is also ready to pick up. 30 parts in total. Yikes!!! Another nice bill. Hope to have some photos coming soon.