Wiseco 1179 Kit, 1979 XS1100SF

[sightseeing]

Anyone installed 1179 Kit on a 79'?
What Dyno Kit to use? Read some good posts by 'Dan Hodges'

[LAB3]

As a follow up to the first question would a cam swap be a better "bang for the buck"?

[cajun31]

Had quite a discussion. Wiseco Big Bore Kit - XS11.club Forums

[sightseeing]

I already have head and cylinders, ready to install. I had cylinders and head completed years ago. Some of my spare parts. But as most of you know these bikes don't die. My oldest just started to burn oil, valve seals need to be replaced. But because I have reconditioned parts ready to go, why not just change out.
I would like information from someone who has already done an install of 1179 kit, with carb jetting done.

[DiverRay]

There should be no jetting needed.I'm working on an engine now that will have the 1197 kit and plan on starting with stock carbs. Any changes to the jets SHOULD start from stock. The carbs meter the gas/air already, and unless you change air intake/filter or the exhaust, stock will work.
My guess is you will need to go up one size on the main with stock airbox, but that depends on the gas you use. Ethanol fuel is lighter, and you need to increase one jet size for that.

[cajun31]

I already have head and cylinders, ready to install. I had cylinders and head completed years ago. Some of my spare parts. But as most of you know these bikes don't die. My oldest just started to burn oil, valve seals need to be replaced. But because I have reconditioned parts ready to go, why not just change out.
I would like information from someone who has already done an install of 1179 kit, with carb jetting done.

If you read through the thread I posted the one person that had actually done the kit did indicate he also installed a Dynojet kit. I also know that one of our adminstrators that we don't hear from too often is TC Gresham better known as Topcat. I know he installed the kit years ago. I remember several comments from him over the years that the kit itself doesn't do much for performance upgrades but was one of the few alternatives at the time of his installation to basically refresh the motor for the same reasons as you have indicated. Like crazy steve, another long time member that you never hear from on this forum anymore stated Yamaha basically abandoned support for the xs1100 when they released the FJ. Many have used kits from this company and I am sure rejetting requirements are similar. Search Results for “xs 1100” | Page 2 | CRUZINIMAGE.NET.
Maybe someone will see this message and chime in. By the way jets are not really cost prohibitive and you could always just experiment on your own. I know that is not the best alternative but is an option. Jets R Us is where many buy genuine Mikuni jets from. Sounds like you are well on your way.

[sightseeing]

Thanks for the information.
I understand that more volume of air intake to cylinders and compression going up will change vacuum to CV carbs. I am going to start with DJ kit one for 78' 79'. Use my color Tune also. The carbs are jetted different then 80' or 81 due to EPA. Tuning should work out. I just don't what to dyno bike to tune, my 78 and 79 Perform so well right now. I read Dan Hodges article, informative.
Thanks again.

[cajun31]

Thanks for the information.
I understand that more volume of air intake to cylinders and compression going up will change vacuum to CV carbs. I am going to start with DJ kit one for 78' 79'. Use my color Tune also. The carbs are jetted different then 80' or 81 due to EPA. Tuning should work out. I just don't what to dyno bike to tune, my 78 and 79 Perform so well right now. I read Dan Hodges article, informative.
Thanks again.

You are going to find that you will need to call Dynojet and speak to someone about your specific application. I was browsing their website and they don't specifically list a kit for your year model carbs. They probably have something readily available for you and probably don't specifically list it because you have a lot of things that can be changed and adjusted in the early carbs. It really depends on what you are after. One thing for sure though, Dynojet is going to be a bit more costly then if you just buy your jets from Jets R Us. The pilot jets are probably OK and takes care of idle and plays a factor up to about 75% of the entire range. The main jets and main jet needle adjustment takes care of the rest. Dialing any changes in on the mains without having it Dyno'd with full instruments hooked up is a bit more involved. You are just experimenting without that. Not saying I would go that route either. For me just having the bike run smoothly throughout the entire throttle range is my goal. Running with no stutter and good throttle response and of course reasonable gas mileage it always my goal. Whatever route you go just help the rest of us with your findings. Might be something everyone else can learn from.

[sightseeing]

I should have gone with Jets R US but already have DJ Kit for 78 or 79 bike. I will keep everyone informed.

[e30 gangsta]

Weisco and mikuni rs bike here. Piston kit doesn't really make a huge difference. I didn't feel a big change in power or anything, carbs though different story, best decision I made for this bike.

[gtem]

Weisco and mikuni rs bike here. Piston kit doesn't really make a huge difference. I didn't feel a big change in power or anything, carbs though different story, best decision I made for this bike.

Not to derail the big bore kit conversation, but I'm curious: what is the theory behind any big increases in power from a carb swap? Larger throat to allow more air in and more fuel to go with it? Is it more peak power at the expense of low/mid range? I know some people prefer the throttle slide carbs for the direct response versus CVs.

[cajun31]

Not to derail the big bore kit conversation, but I'm curious: what is the theory behind any big increases in power from a carb swap? Larger throat to allow more air in and more fuel to go with it? Is it more peak power at the expense of low/mid range? I know some people prefer the throttle slide carbs for the direct response versus CVs.

RS vs CV is more about performance based riding vs everyday riding. RS carbs provide more or immediate throttle response vs CVs. There are pros and cons for both. CV carbs are for lack of a better word smoother than RS carbs across the entire range. CV carbs will also handle altitude changes whereas with RS carbs you might have to adjust them. The pros of RS carbs are that they can be more finely tuned then CVs. When I first purchased my 2002 Harley Davidson Night Train I swapped out the HD CV carb to the Mikuni HSR 42 flatslide carb and the difference was immediate. It went from a bike that felt restricted to one that could breath. Of course I also replaced the stock exhaust with an aftermarket vance and hines HS pro pipe that let the bike breath. Marked improvement in performance overall. Much the same effect that can be gained on our bikes especially if you pair the flatslides with the proper exhaust. As these bikes age and parts become unobtanium aftermarket solutions have to be utilized. Same reason some have ventured into EFI.