H.P. difference between 78 E & later models

[Dan Hodges]

Xexcessive 1120 asked what made the 78 E stouter than it's siblings. Good question and here is the answere. The 78 had 10 degrees of initial timing and 26 degrees of centrifugal for a total of 36 degrees. The 79 F had 5 initial & 31 centrifugal for a total 36 degrees. Same deal for SF. 78 & 79 models had 12 degrees more cam timing than later models but had 2mm smaller intake valves and 1mm smaller ext. valves and a quarter point more compression. The 80 models had the big heads and small cam and 5 degrees initial timing with 30 degrees centrifugal for a total of 35. The 81 S&SH both had 5 degrees initial but had 35 degrees centrifugal for a total of 40 degrees. Starting in 80, all elevens had electronic ignition (they eliminated the mechanical advance). The fuel curve for the 80 and 81 models were lean at off idle and in the midrange in the interest of lowered emissions. The camshaft center lines were 105 degrees for the later models and 101 for the 78 and 79. Starting in 79, California models had different pilot air jets than 49 state models. The bottom line is, use the 78-79 cams, 80-81 heads cut .030, 78 advance curve and the 80-81 carburetors with 180 pilot air jets, stock pilots, 112.5 mains for stock pipes, 115-120 mains for good flowing headers.A good ring seal and you got yourself a runner. A C.B.X. killer. V-65, maybe.

[John]

You wouldn't want to use the 78-79 carbs which are much more tunable, over the 80-81 carbs which are not? My 80SG has the original vacuum advance, and it is of the mechanical type. It had the factory break away head fasteners that secure the pick up coil plate to the engine. The vacuum advance appears to be the same as my 78E Organ Donor. I wasn't aware that the cams were that different. Maybe I'll swap the cams from the 80 for those of the 78. Would it behoove me to also swap my 80 pick up coils, and the reluctor and counter weight springs for those from the 78? I have the 1179cc big bore kit in my engine. I would like to have half a chance of keeping up with that new Damned FJ1100 that SWMBO just bought.

[pathfinder]

Never happen, sorry

[Ken Talbot]

Never say never, Pathfinder. John can always go out and yank off a plug wire from his SWMBO's FJ. Then he might have a chance of keeping ........... up......

[pathfinder]

Sugar in the gas tank. Nah then he'd just have to fix it. Or he can put those high dollar Tygon (fuel only) lines on and use it as vacuum line and it will collapse under high revs and starve it for fuel. That will take her awhile to figure out. And he will get on her good side for doing something she didn't ask for, you know kinda like flowers

[scalded dog]

Which bike is more comfortable on a long ride, the xs eleven, or the fj 1100? One of the guys in our club has an fj 1100, It don't look very comfortable. Later 'Dog

[chevy45412001]

even more speed

I never hear of anyone taking weight off the crank to make her rev quicker? Less rotating mass?Faster reving less weight more POWER. I heard 14lbs. to much What about 7-9 lbs less in the crank heft. Still would need to be careful not to miss a shift though.

[John]

I have only ridden her current FJ a few times. Basically just test ride after repairs. I did ride it for 25 miles once, and my wrists, elbows and shoulders were sore, so IMHO, my XS, the way it is set up is much more comfortable on a long ride. I am accustomed to the 'Sit up and beg' position of my bike. hell, I don't know if I would be comfortable on my own bike if it wasn't for the adjustable back rest. Hell the FJ is considered a'Sport/Tourer' so it's supposed to be comfortable but I don't know...
Back to my original question... would the changes I asked about increase my performance to a noticable degree? I have all the pieces to do the job.

[Wildkat]

Originally posted by Ken Talbot
Never say never, Pathfinder. John can always go out and yank off a plug wire from his SWMBO's FJ. Then he might have a chance of keeping ........... up......

Hmmmmm.... He'll have to catch me first...

[chevy45412001]

change spring rate

i did an accel spring swap on my capprice classic w/ 350 stock internals w/ headers and duel exhaust. Gain 1/2 sec off my 1/4 mile time at the drag strip.Mind you that was my car,but if the total timing comes in a few hundred rpm's less you should be able to feel it in the seat of your pants. But in mho i think your chasing ghosts. Even though it would be a lil quicker i don't think your top end would change much.3-5mph, maybe.

[pgg]

John, I'd stick with the 80' cams, they're better than 78's for road/street. They've got better low and midrange.

[Dan Hodges]

Cam's

I thought this subject had been made clear before,but I guess not.With out going into another long winded explanation again,the bottom line is.The 78-79 cam's makes more power from 5000 rpm up than the 80-82 cam's and raise the power /torque peak 300-500 rpm.The late cams had less duration,less overlap and wider lobe centers than the early ones and was an attempt by the factory to lower the emissions.Not many people ride their Eleven down the highway at 4500 rpm,if you do the Harley's will run over you and we cannot let that happen can we.XS Eleven's were never lacking bottom end power,but they can use some more top end and a increase in camshaft timing is the way to get it as long as you do not get stupid and try to run drag race cam's on the street.If you want to spend the money,Mega Cycle and Web Cams both have welded regrinds that work very well.The stock 78-79 cam's are cheap and easy to find and will give your 80-82 Eleven a mild increase in top end performance.