Tweet
Hello from down here in little old New Zealand. Heres an xs1100 musclebike you lot might be interested in. Its a 78e / 80sg hybrid. Over the last few years heres what was done to it.
1. Cycleworks 4-1.
2. K&N air filter.
3. Drilled airbox & airscoop.
4. 147.5 main jets (mikuni) 47.5 pilot jets (mikuni)
180 pilot air jets (mikuni) Slide vacuum holes 3mm
Needles centre notch Floats 26mm.
5. Dynacoil ignition.
6. 1196 wiseco pistons (10.25-1)
7. Timing retarded 3 degrees.
8. BP7es plugs (.040 gap).
9. Ported and flowed cylinder head.
10. 80sg inlet & exhaust valves (About 2mm larger than 78e).
11. 80sg cams (With less duration than 78e cams, the 80sg cams give better low and midrange torque because of less overlap and .020 more lift on the exhaust side. The 78e cams dont "come on cam" until 3000 revs).
12. Clutch has an extra steel plate and stiffer springs.
13. Progressive fork springs.
14. Konis on the back.
15. Fork brace up front.
16. Reinforced frame up front.
17. The motor and gearbox are 80sg, carbs, frame, wiring and most other parts are 78e (Shorter gearlever needed for rearward angled 78e footpegs).
18. Stainless brake hoses upfront.
Those engine mods gave power increases, some small, some bigger. The most noticable are the big bore pistons (Definite torque increase) and the ported head, which gives the motor a boost that can be really felt.
The pilot circuits need to flow plenty of fuel to keep the ported head running smooth down low, so combined large main and large pilot jets were needed for clean running on a middle clip position. Also plenty of air too. The standard 140 main air jets dont need modifying, as they run fine with an improved air intake.
The dynacoils give a good "crackity crack" feel, and the 4-1 adds some zest too. Slightly retarding the timing and colder plugs keep the combustion in shape, and bigger valves help the gases flow. An extra steel plate in the clutch deals to any slipping.
This old dinosaur can chug along effortless at 1800 revs in 5th gear, and pulls like a tractor from 2400 revs in all gears. Fuel use is good at 40 mpg at 62 mph, but crank it up and milage suffers. Because the extra power in this tweaked motor is found between 2000 and 8000 revs, The actual flat out top speed is basically no different than on your stock standard bike, although it gets there quicker (About 8200 revs in top gear on a good day)
Mind you, a 5ft 2 inch , 50 kilo test rider, in one peice leathers, in a tailwind could probably wring out a few more revs from these bikes. Being 6ft 3 inch & 100 kilos I dont qualify. To get a high rev, screaming top end on the poor old gasping 2 valve motor, You'd probably have to spend megabucks on 1. A high lift, high duration camgrind in conjunction with 2. A lightened and modified valve train - eg lightweight direct on cam tappets, tiny direct on valve shims, lightweight valves, altered valve seats, guides, race springs etc.. and 3. A bank of mean and nasty flatslides.
All of which would be a right pain in the a** on a street bike. You'd be giving the 68mm piston stroke a damn good workout too. Aeroynamics come into it, and no one could call a big hulking xs11 "slippery". As for dialing in the cams, the 1hp gain (If you're lucky) just doesn't make the cost of adjustable sprockets worthwhile at all.
Dont be suckered into believing a hotted up motor is going to give enormous earth-shattering blasts of mega-horsepower and performance, as the standard xs1100 motor was surely designed to put out major stomp right from the start. Tricking up the motor (For a "useable" streetbike) simply gives the engine characteristics an overall improvement.
Anyway, forgetting meaningless figures and numbers on paper, the real world noticable difference on this bike over stock, is in extra grunt across the rev range and more acceleration. Pickup from 0 - 120mph is wicked. You could probably alter the gearing on an xs11 by getting a machine shop to make up a set of different ratio middle drive, middle driven, and final drive cogs, then swap them into the gearbox... sounds simple, but possible dramas and mental anguish may be involved. Just getting into the b*** gearbox is a drama in itself.
In the end, if 130mph isn't fast enough, go get aZX12R and eventually kiss your licence goodbye!
<A HREF="http://www.imagestation.com/album/?id=4289346089"><IMG SRC="http://www.imagestation.com/images/is/community/this_album_button.gif" BORDER="0"></A>
1. Cycleworks 4-1.
2. K&N air filter.
3. Drilled airbox & airscoop.
4. 147.5 main jets (mikuni) 47.5 pilot jets (mikuni)
180 pilot air jets (mikuni) Slide vacuum holes 3mm
Needles centre notch Floats 26mm.
5. Dynacoil ignition.
6. 1196 wiseco pistons (10.25-1)
7. Timing retarded 3 degrees.
8. BP7es plugs (.040 gap).
9. Ported and flowed cylinder head.
10. 80sg inlet & exhaust valves (About 2mm larger than 78e).
11. 80sg cams (With less duration than 78e cams, the 80sg cams give better low and midrange torque because of less overlap and .020 more lift on the exhaust side. The 78e cams dont "come on cam" until 3000 revs).
12. Clutch has an extra steel plate and stiffer springs.
13. Progressive fork springs.
14. Konis on the back.
15. Fork brace up front.
16. Reinforced frame up front.
17. The motor and gearbox are 80sg, carbs, frame, wiring and most other parts are 78e (Shorter gearlever needed for rearward angled 78e footpegs).
18. Stainless brake hoses upfront.
Those engine mods gave power increases, some small, some bigger. The most noticable are the big bore pistons (Definite torque increase) and the ported head, which gives the motor a boost that can be really felt.
The pilot circuits need to flow plenty of fuel to keep the ported head running smooth down low, so combined large main and large pilot jets were needed for clean running on a middle clip position. Also plenty of air too. The standard 140 main air jets dont need modifying, as they run fine with an improved air intake.
The dynacoils give a good "crackity crack" feel, and the 4-1 adds some zest too. Slightly retarding the timing and colder plugs keep the combustion in shape, and bigger valves help the gases flow. An extra steel plate in the clutch deals to any slipping.
This old dinosaur can chug along effortless at 1800 revs in 5th gear, and pulls like a tractor from 2400 revs in all gears. Fuel use is good at 40 mpg at 62 mph, but crank it up and milage suffers. Because the extra power in this tweaked motor is found between 2000 and 8000 revs, The actual flat out top speed is basically no different than on your stock standard bike, although it gets there quicker (About 8200 revs in top gear on a good day)
Mind you, a 5ft 2 inch , 50 kilo test rider, in one peice leathers, in a tailwind could probably wring out a few more revs from these bikes. Being 6ft 3 inch & 100 kilos I dont qualify. To get a high rev, screaming top end on the poor old gasping 2 valve motor, You'd probably have to spend megabucks on 1. A high lift, high duration camgrind in conjunction with 2. A lightened and modified valve train - eg lightweight direct on cam tappets, tiny direct on valve shims, lightweight valves, altered valve seats, guides, race springs etc.. and 3. A bank of mean and nasty flatslides.
All of which would be a right pain in the a** on a street bike. You'd be giving the 68mm piston stroke a damn good workout too. Aeroynamics come into it, and no one could call a big hulking xs11 "slippery". As for dialing in the cams, the 1hp gain (If you're lucky) just doesn't make the cost of adjustable sprockets worthwhile at all.
Dont be suckered into believing a hotted up motor is going to give enormous earth-shattering blasts of mega-horsepower and performance, as the standard xs1100 motor was surely designed to put out major stomp right from the start. Tricking up the motor (For a "useable" streetbike) simply gives the engine characteristics an overall improvement.
Anyway, forgetting meaningless figures and numbers on paper, the real world noticable difference on this bike over stock, is in extra grunt across the rev range and more acceleration. Pickup from 0 - 120mph is wicked. You could probably alter the gearing on an xs11 by getting a machine shop to make up a set of different ratio middle drive, middle driven, and final drive cogs, then swap them into the gearbox... sounds simple, but possible dramas and mental anguish may be involved. Just getting into the b*** gearbox is a drama in itself.
In the end, if 130mph isn't fast enough, go get aZX12R and eventually kiss your licence goodbye!
<A HREF="http://www.imagestation.com/album/?id=4289346089"><IMG SRC="http://www.imagestation.com/images/is/community/this_album_button.gif" BORDER="0"></A>
Comment