Land speed bike project

[rbmgf7]

Hello, I'm a new owner of a used 79 XS1100F.



I picked up this bike because I have the wild idea of seeing how fast I can make it on a flat surface. A bit crazy and not the best choice but it'll be something fun to do on the side. Please spare me the "it's dangerous speech". I know it's dangerous. We all need to take a risk every now and then .

I know speed costs money so I want to do the hobo approach and keep it on a budget. I may not reach the potential max speed that this bike is capable of but I'll reach the fastest speed my wallet is able to provide, lol.

The first step I want to make is upgrade the fuel delivery. I owned an XJ1100 for a while and I hated the CV carbs. All the other carbs I ever messed with were round slides. Essentially, I want to get away from CV's.

I've seen people adapt DCOE 40s to a lot of older liter bikes, including the XS/XJ. I'm seeking advice for a good, not too expensive, alternative to help this bike's fuel delivery at higher speeds.

This might not be the ideal start point for performance but since I lack carbs, I need something.

Making a manifold isn't a problem. I have plenty of tools to make some so I'm up for the challenge.

I know there's other alternatives like CR's, FCRs, etc. but for some reason I really dig the Webers.

Maybe some old timers can pitch in their $0.02?

Thanks,

Ray

[DiverRay]

OK, on a budget.....
1. Tkat fork brace. You need to control the bike at speed.
2. flatslide carbs, maybe off a large KAW as they are cheap, easy to tune for top end, and work well.
3. 850 final drive swap. This will give you higher top end, in theory..
4. use the 4 intake horns on the stock airbox to even the flow of air, if they will fit the flatslides. If not, get some that do fit.
5. Barnett clutch springs, cause the clutch WILL slip....
6. flat bars in place of the pullbacks, so you are down on the bike, not a door.
Ok, that's a start. As you see, I didn't go with webbers as they cost too much. Even used they are about $300 each, and for the CFM they flow you can do just as well with newer MC carb sets.
Take pics!

[MaximPhil]

Hi Ray,
I am a big fan of land speed records. I presume you have watched Worlds Fastest Indian ? For inspiration try http://www.bloodhoundssc.com/
Porsche managed to get over 100hp per litre 425 hp out of 3.8 L air cooled normally aspirated motors but they have had 50 years of development and it did not come cheap.
Back to your project. In standard trim the XS will do well past 125 mph while still being a well mannered ride around town and touring. How much faster do you want to go? As already mentioned horsepower costs money and tires will only take so much. Everything on the bike needs to be in first rate condition.
Bearings that might seem fine after 30+ years might not be up to the strain of sustained high speed operation
Please remember the public highway is not the place for this sort of fun
Bonneville in August will let any properly prepared machine run on the salt flats if you want to go that kind of fast.
See you are among friends equally crazy as you
Phil

[rbmgf7]

OK, on a budget.....
1. Tkat fork brace. You need to control the bike at speed.
2. flatslide carbs, maybe off a large KAW as they are cheap, easy to tune for top end, and work well.
3. 850 final drive swap. This will give you higher top end, in theory..
4. use the 4 intake horns on the stock airbox to even the flow of air, if they will fit the flatslides. If not, get some that do fit.
5. Barnett clutch springs, cause the clutch WILL slip....
6. flat bars in place of the pullbacks, so you are down on the bike, not a door.
Ok, that's a start. As you see, I didn't go with webbers as they cost too much. Even used they are about $300 each, and for the CFM they flow you can do just as well with newer MC carb sets.
Take pics!

Thank you. That's a LOT of great info.

Which model should I look into for carbs? KZ, Ninja, Concours? Any specific years or will they all work?

Hi Ray,
I am a big fan of land speed records. I presume you have watched Worlds Fastest Indian ? For inspiration try http://www.bloodhoundssc.com/
Porsche managed to get over 100hp per litre 425 hp out of 3.8 L air cooled normally aspirated motors but they have had 50 years of development and it did not come cheap.
Back to your project. In standard trim the XS will do well past 125 mph while still being a well mannered ride around town and touring. How much faster do you want to go? As already mentioned horsepower costs money and tires will only take so much. Everything on the bike needs to be in first rate condition.
Bearings that might seem fine after 30+ years might not be up to the strain of sustained high speed operation
Please remember the public highway is not the place for this sort of fun
Bonneville in August will let any properly prepared machine run on the salt flats if you want to go that kind of fast.
See you are among friends equally crazy as you
Phil

Yeah, no record breaking. Just seeing what the bike can do with what I have. Yes, I have watched The Worlds Fastest Indian but I was watching another Youtube video and noticed BMST offered the Run Watchya Brung which gain my attention. After more research, I found out some more land speed trails that go on, especially more East. There's one in Ohio that's literally an hour away from me that takes place on an old air strip. Albeit it's only a mile, it's more than enough to prepare for a Bonneville trip.

I'm just taking baby steps and hashing out a plan.

First, just get it running again which is why I came here to consult for carb replacements.

Next is to benchmark it and find out where the old girl is at. There a couple dyno shops an hour away I can take it to to get some results and make some adjustments if needed.

Next would be to start making the needed frame/handling adjustments. I'm going to rake and slam it as far as I can go. This would be the end of it for the first phase. By then, I hope to enter in at least one of the Ohio Mile events (there's usually 3 or 4 held a year).

After that, it's time to crack open the cases and start balancing, P&P, upgrading the cam, and valves.

I already know I'm mechanically limited by the shaft drive. By that time, I'll see where I stand and either seek a chain conversion or move onto a more capable engine (sorry, I know it won't be an XS anymore if I do).

[trbig]

There are a few chain drive conversion kits out there. That would get much more of what little HP these old bikes make to the ground than you'll ever get through the twists and turns of the shaft drive system. There are also a few people who've run fuel injection, and some with turbos. A properly tuned bike in stock form will get you somewhere in the neighborhood of 135-140 mph in good conditions. A modern 600cc bike will smoke these in every way and will probably be a lot cheaper than what you have in mind, unless there's some antique class you're wanting to run it in.

[fullmetal]

This is a pretty interesting topic. I don't know too much, but I do know a lot of the 90s ninjas came with keihin flatslides.

[crazy steve]

There are a few chain drive conversion kits out there. That would get much more of what little HP these old bikes make to the ground than you'll ever get through the twists and turns of the shaft drive system. There are also a few people who've run fuel injection, and some with turbos. A properly tuned bike in stock form will get you somewhere in the neighborhood of 135-140 mph in good conditions. A modern 600cc bike will smoke these in every way and will probably be a lot cheaper than what you have in mind, unless there's some antique class you're wanting to run it in.

He's giving you the straight poop here.... The XS design left very little extra performance potential on the table as built. You can squeeze about another 20 HP out of one if you pay slavish attention to detail and can track down a lot of long-discontinued parts or are willing to have them custom-built. Anything above that and it gets even more horribly expensive quickly.

LSR is a game of ultimate horsepower. The XS is a durable, reliable design that makes very good power given it's age, but it simply can't compete with more modern designs unless you do a power-adder like nitrous, a blower or turbo. You're now out of the 'low budget' category. Also keep in mind that STOCK internal engine parts like rings, bearings, pistons, valves, etc are all long discontinued and getting very difficult to find, so before you split the cases make sure you have parts lined up. Hi-po versions are even harder to find....

[motoman]

Hello, I'm a new owner of a used 79 XS1100F.



I picked up this bike because I have the wild idea of seeing how fast I can make it on a flat surface. A bit crazy and not the best choice but it'll be something fun to do on the side. Please spare me the "it's dangerous speech". I know it's dangerous. We all need to take a risk every now and then .

I know speed costs money so I want to do the hobo approach and keep it on a budget. I may not reach the potential max speed that this bike is capable of but I'll reach the fastest speed my wallet is able to provide, lol.

The first step I want to make is upgrade the fuel delivery. I owned an XJ1100 for a while and I hated the CV carbs. All the other carbs I ever messed with were round slides. Essentially, I want to get away from CV's.

I've seen people adapt DCOE 40s to a lot of older liter bikes, including the XS/XJ. I'm seeking advice for a good, not too expensive, alternative to help this bike's fuel delivery at higher speeds.

This might not be the ideal start point for performance but since I lack carbs, I need something.

Making a manifold isn't a problem. I have plenty of tools to make some so I'm up for the challenge.

I know there's other alternatives like CR's, FCRs, etc. but for some reason I really dig the Webers.

Maybe some old timers can pitch in their $0.02?

Thanks,

Ray

As a 'shaftie', 132mph, then Mother Nature wins.

[Bikes]

We have LSR every summer up here at the old Loring Air Force Base in Limestone....waaaay up north......bring her up, lets see what happens......I'll go with you.........
http://www.loringtiming.com/