Murray Carb's

[MechanicalRebel]

Planning on saving money and buying murray's carbs. While my bike runs great the carbs the carbs need a lot of work and nothing I do will give me better fuel mileage (estimated im getting 20 mpg). How do I go about my vacuum advance with these carbs. TIA.

1981 xs1100sh

[e30 gangsta]

Don't waste your time with those carbs they're junk. Buy mikuni rs36's instead.

[Schming]

Don't waste your time with those carbs they're junk. Buy mikuni rs36's instead.

Do the RS carbs fit with the stock air box ?

[oldyam80sg]

Or ZRX carbs or do what I did and get 96 Kawasaki GPZ 1100 carbs.

[Bonz]

I am struggling to reconcile "The bike runs great" and "20 mpg". It's not a vacuum advance issue. What exhaust are you running, airbox or pods?

ZRX carbs are a much better option than flatslides of any kind.

Oldyam80sg, how's the ZRX/GPZ carb swap going?

[e30 gangsta]

Flat slides are much better than any cv style carb. Especially if they're tuned correctly. You cannot compare them. The difference in performance is huge.

[oldyam80sg]

Bonz-the carbs are ready to go.I just yesterday put on the stock Yamaha carbs to ride the bike to my Moms house. I just need a free day as I was called into work. Once the bike is at my Moms house,the swap will happen.

[Bonz]

Not debating flat slides are a better performance modification. That wasn't part of your original post. Adding that info at this point changes the lens we are looking at this through. What is the performance gain you are expecting? There must be a number you're comparing to the stock carbs because of your statement.

Are you trying to make the XS1100 keep up with more modern bikes? A 605 pound two valve head 1100 that's 40 years old isn't your huckleberry.

The Murray set up is two carbs, each feeding adjacent cylinders. You need a vacuum port to run the vacuum advance, don't know how that may work given that set up with vacuum pulses coming through the runners at different times. Find a place you can put in a fitting in those runners and run your line up to it. Try it.

With that said, I disagree with the statement. "Nothing I do will give better gas mileage". Nothing you have done to this point has done better. 20 mpg is literally dumping gas through the engine.

[LAB3]

20 mpg is literally dumping gas through the engine.

I've just spent the better part of the month hitting all the twisties in the smoky mountains and no matter how hard I run my bike I couldn't get down to 20mpg.

[Ranger_xs1100]

I've just spent the better part of the month hitting all the twisties in the smoky mountains and no matter how hard I run my bike I couldn't get down to 20mpg.

No matter which one of my 11's I ride, I set the trip-odometer and stop to fuel up full every 100 miles. Always takes ~ 3 gallons (US).

[oldyam80sg]

Even if the carbs are dirty, I still got 32 mpg.Clean carbs will give good mileage. Also check air filter for dirt.You said in first post estimated you cant get 20 mpg-my 97 Jeep cherokee got 17+ and was way lot heavier than an XS.

[Tonyxs11]

if we where talking about cars and fuel i could understand. but we are bikers here so fuel consumption shouldn't even be a thought !!!!! just get on it and ride

[oldyam80sg]

Amen Tony!!

[DiverRay]

That's true, Tony. But you do need to look at what he is saying, 20mpg instead of the 30+mpg most of us get. You do NOT want unburned gas going past the rings and into the oil. If it is burning it, you will know by the smoke out of the exhaust and lack of power.

[Tonyxs11]

That's true, Tony. But you do need to look at what he is saying, 20mpg instead of the 30+mpg most of us get. You do NOT want unburned gas going past the rings and into the oil. If it is burning it, you will know by the smoke out of the exhaust and lack of power.

yeah true Ray, but I must admit the way I used to ride 20mpg would of been good im a bit more sedate these days.