Xs650 runs great but max speed 65mph

[Jake Violando]

Hello, my xs650 just received a new front timing chain guide and I cleaned up the pistons, new clutch, and tune on the carbs. Along with the rubber diaphragms in the carbs. Runs like a champ, gets to 60 quick but tops at 65. I've heard I should be able to do 100 easy with my 17t 32t sprockets. I have bs34 carbs. What can I do?

 

[azman857]

Throttle fully opening? Advance fully advancing? Valve clearance in spec? Exhaust not blocked?

 

[gggGary]

What does the engine do between 60 65? miss, stutter, plain quit, rev up?
What ignition and alternator? What air filters?
What are you getting for compression?

 

[TwoManyXS1Bs]

Not sure how to approach this.
We still have the unresolved issue of TDC piston interference:

http://www.xs650.com/threads/cant-get-alternator-marks-to-line-up-for-timing.49117/

http://www.xs650.com/threads/motor-spun-fine-on-bench-now-in-frame-wont-kick.49296/

 

[Jake Violando]

All that's figured out. Bike runs good S stated above

 

[Jake Violando]

What does the engine do between 60 65? miss, stutter, plain quit, rev up?
What ignition and alternator? What air filters?
What are you getting for compression?

Engine just hits really high rev. Doesn't sputter or anything, runs good as I already stated.

 

[Jake Violando]

Throttle fully opening? Advance fully advancing? Valve clearance in spec? Exhaust not blocked?

Valves are in spec and throttle is opening all the way.

 

[Jake Violando]

I'm not sure if no one read my thread or if I wrote it wrong. The bike runs great. Which means no sputtering or anything. Revs out perfect. Valves are In spec, carbs are set, pod filters on bs34 Carbs, no it doesn't run different with them off. Stock 1980 everything else.

 

[Bob Kelly III]

what is the RPM at 65mph ?

sounds like you either have a sticking advance unit in the timing circuit or a slipping clutch or need to change the gearing to the rear wheel for higher speeds.... but I'm just guessing.
....
if I remember correctly mu 82' is taching about 5500 rpm at 65mph and she has a long way to go from there to red line.
if you don't have a Tach.... that makes it tough to guess but let us know it's a guess or not please
.... I think everyone read the post Jake .... but went in to immediate fix it mode ! LOL
Bob.......

 

[gggGary]

Yes sounds like he's saying the clutch is slipping but we are working from thin clues. There's a chance top speed will be in 4th with a 32 tooth rear sprocket, depending on the rim size, tire and on the front wheel/tire affecting speedo accuracy.

I see a mini speedo, those come in two flavors Japanese and Harley drive ratio. And not all of them work great. Get the phone out and check GPS speed.

 

[B Burdine97]

Im with 2M on this one. I have followed your past threads Jake and you did not share with us what solved your motor that wouldnt turn over all the way. Alot of us put time into helping others and like to hear the outcome or the solution. What did you do to fix your engine not turning over all the way?? What was the issue?

 

[Jake Violando]

Im with 2M on this one. I have followed your past threads Jake and you did not share with us what solved your motor that wouldnt turn over all the way. Alot of us put time into helping others and like to hear the outcome or the solution. What did you do to fix your engine not turning over all the way?? What was the issue?

A spacer from the top cover on a piston, all good now.

 

[Jake Violando]

No rpm gauge, but how do I check my advance? Speedo is accurate. Clutch is new.

 

[azman857]

Gotta timing light? Or take the cam end cover off the RT side and check to see if the weights snap back.

 

[Jake Violando]

Their is no weight I have empty covers on the inside

 

[Bob Kelly III]

ok so what ignition system do you have on that thing ? it's getting it's spark from somewhere !
if it's electronic ignition then the spark advance is probably fine... so that only leaves a few things that could cause the RPM not to rise with the throttle when above mid range RPM ...... that is what your asking us to figure out ....Right ? the engine runs great just doesn't pull at higher RPM ?
Have you done a plug color check ? what color are the spark plug tips !
....
Bob.........

 

[barr toy]

Hi Barry here I am having the same trouble. Runs out of steam at about 65 mph. Has 18/30 gearing. I know that ever one will beat me off the line. But still I should be able to do over 100 mph. 1979 special. Note the bike will speed up some if I roll the throttle back a little. Am I running to rich? Please help. P S the is stock.

 

[TwoManyXS1Bs]

Jake, Barry, see if anything in here sounds familiar:

http://www.xs650.com/threads/wont-go-above-60mph.37657/

 

[nj1639]

^ I'll take #36 in post #16 Alex! ^

 

[grizld1]

Barry, getting more power rolling off a bit from wide open throttle is usually a lean signal. A rich condition usually results in a sputtering misfire when you roll off from WOT to around 3/4. Your bike seemed to be running well at Dogwood; has something changed?