Tweet
Hi my pals. I just put a new set of plugs in my 79SF and what a difference it made. However, I'm wondering if my low RPM characteristics are "normal". Bike starts and runs very well. Power seems very good. However, it doesn't really wake up until 3500 RPM at which point there is a noticeable power surge. Also, below 3500 RPM the power seems quite soft and it sorta seems like its a little erratic, maybe surging/hesitating. It's not dramatic, but I'm wondering if this is just the nature of the beast or if I need to check out my low speed jetting. Any thoughts/input???
-
'79 XS11 Special, fork gaiters, Uni pods, 45 pilots, 140 mains, ditched the octy, solo seat, T kat fork brace
Purrs like a kitten, runs like a scalded cat
-
Yeah, 3500 is where the motor 'gets up on the cams' and really takes off. That's pretty much normal. As to low-speed 'hesitation' or 'surging', make sure you're not feeling 'driveline snatch'; these bikes have always been noted for this. If you still feel it under light acceleration or going up a small incline, then look at your idle mixture and/or low speed jetting.Fast, Cheap, Reliable... Pick any two
'78E original owner - resto project
'78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
'82 XJ rebuild project
'80SG restified, red SOLD
'79F parts...
'81H more parts...
Other current bikes:
'93 XL1200 Anniversary Sportster 85RWHP
'86 XL883/1200 Chopper
'82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
Cage: '13 Mustang GT/CS with a few 'custom' touches
Yep, can't leave nuthin' alone... -
I know the 2500-3500 range is where the main jets kick in, but personally, I can't "feel" the difference when it happens. Your pilot jets may be slightly clogged, causing the hesitation at low RPMs. How long has it been since you pulled them out and cleaned them?1980 XS850SG - Sold
1981 XS1100LH Midnight Special (Sold) - purchased 9/29/08
Fully Vetterized and Dynojet Kit added, Heated Grips, Truck-Lite LED headlight, Accel Coils, Irridium plugs, TKAT Fork Brace, XS850LH Final Drive & Black SS Brake lines from Chacal.
Here's my web page devoted to my bike! XS/XJ User's Manuals there, and the XJ1100 Service Manual and both XS1100 Service manuals (free download!).
Whether you think you can, or you think you cannot - You're right.
-H. FordComment
-
Take a look at the XS 11 motorcycle magazine tests that are available on this forum. At least one of them says the same thing, that the power really comes on above 3500 rpm.
That is how mine is as well. It's just a steady increase in acceleration below the 3500 range, then transitions into more of a rush/harder pull around 3500 rpm or so.
Back in the day, most UJM's had their power bands up higher than, say, my 2001 ZRX 1200 or my old Bandit 1200. Those have the best of both worlds, with 16 valve heads.Howard
ZRX1200
BTW, ZRX carbs have the same spacing as the XS11... http://www.xs11.com/forum/showthread.php?t=35462Comment
Comment