Acceleration

F

F@b

New Member
I dont know if any body else has this problem. When I rebuilt my 1972 Cl350 and put those old looking Firestone tires on the front and back and then rebuilt the whole motor it ran great, but i hear everybody talking about how they go 70 mph at around 5700 rpm's on the road like it is no problem, It takes me alot of work to get to 70 mph and Iam at well over 9000 rpm's and it has to be on flat road. so does my bike have a problem? Also i run high rpm's at 50, and 60.
 
Could be a few things, but would need to know a bit more info about your bike and any changes you made. Have you made any changes to the exhaust, air filters, carbs, etc.? It could also be a slipping clutch. Have you gone through all the typical maintenance things to ensure everything is to spec; like valve clearances, compression, timing, etc.?
 
You have an issue. Could be a few things... Let's start with the basics.

What intake and exhaust setup are you running?
Is timing set properly?
Valves adjusted correctly?
Coils and plug wires in good condition?
Any modifications to the motor or carbs?
Cluth adjusted properly and all components in good order?
And last but not least... Though unrelated to your issues, are you running those Firestones on stock wheels?
 
if your clutch is slipping you probably would know it
but try accelerating away in 3rd gear and as you accelerate apply the front brake,doing this should slow the bike and drop rpm's but if the clutch starts slipping you will know its a problem and also get a feel for what it feels like when slipping
 
Yes Iam running stock wheels with the firestones. The motor has 0.25 over pistons new valves, K&N cam chain tensioner, and stock kehin carbs with stock exhaust. Cl350 exhaust. I replaced the cam chain and clutch disc's, but not the plates. The bike has 12400 miles on it and 4000 after the rebuild.
 
The only explanation is either:
A) you have a ridiculously large rear sprocket
B) your clutch is slipping like mad
 
K&N cam chain tensioner...

9k rpm at 70 in 5th is not correct. Are you sure you are at 9k? Or are you just at 70, and maybe..6700-6900RPM or so?
 
Yeah, if it runs strong but tops out fast you've got a gearing problem. If its taking you forever to get up to speed AND it tops out at like 70, you've got bigger problems.
 
Right.

Put plainly, if you have stock gearing and your clutch isn't slipping, you cannot be at 70mph and at 9k rpm. It is an impossibility.

Check again to make sure. It sounds, from your other thread and this one, that either your clutch is slipping and you are topping out at 9krpm and 70mph, or you can only go 70mph and you aren't actually at 9krpm. More like, as I said, around 6.8k or so.
 
Or his tach/cable is 40 years old and shot. Combine that with other issues (still no word on intake setup or whether the valves/timing/etc are correct).
 
You guys all have valid points.

But I think it's pretty obvious that with his current coefficient of drag his terminal velocity is 70 mph. And as such the overwhelming power of the cb350 is causing massive wheelspin trying to push past this invisible barrier, so the rolling 70mph burnout explains the 9000 rpms.
Should be pretty easy to tell if this is happening: At 70mph look back, if theres a massive cloud of smoke, thats the issue.
 
What is the actual circumference of those tires? Could it be that you are, indeed, going much faster, but the stock speedo is reading incorrectly now?
 
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