Revving too high on freeway

Finnigan

Finnigan

Over 1,000 Posts
cb360 with stock carbs and near stock length exhaust, timing is right and tappets are good, 520 chain conversion with 17/34T.

First real time on the highway tonight and i got off after a mile because in 6th gear i'm going 70mph and revving at 7,000...?!

The only thing that has not been verified on the engine is compression, but leak down test was solid. Thoughts??

Help please!

**should note that I just installed new clutch springs
 
I don't thinks so, like i said the clutch springs were just replaced with heavy duty ones because that was PJ's suggestion (which helps with shifting, but not with the problem i was trying to fix)
 
RPM to Speed is a fixed gear ratio sort of thing - no tuning issues would cause the engine to rev higher at a particular speed. It has to be mechanical.

Try to sort out the final drive ratio of the engine so you can know what RPM you should see at a given speed. But I'm thinking 70MPH at 7K on a 360 might be about right.

Redline is 9,000 on that bike if I'm right, so you have some room to go and top speed was rated at just over 100 I think. So.... 70MPH at 7K seems about on the money.
 
oh, well that makes me feel a little better. You're right the redline for the 360 is just over 9,000
 
I have the 17/34 and 7000 seems a bit high. I outta know this I ride tween 65 and 70 most of the time, but I can't think what it is exactly. Im thinking I run around 5500 at 65.
are you using Rotella 5w40 blue bottle? I used Mobil 1 t4 motorcycle before my rebuild and my clutch was slipping over 500 rpm at 65, 6000+ before. The rotella, hd springs and fresh disks helped this.

Been a while since I really concentrated my attention to RPM and speed.
 
Yep I've got 5w40 with the suggested additive, now HD springs but the old clutch plates

Should I consider getting new clutch plates or maybe getting sprockets different size?
 
Before getting new plates, try adjusting the clutch again. Use the steps in the first post of this thread: http://www.hondatwins.net/forum/viewtopic.php?f=44&t=8963
 
before doing anything drastic. weather permitting tomorrow i will get you some better numbers.
 
I think if it were the clutch causing this it would be alittle bit more obvious. Just go up a hill holding 60mph and watch the revs or something simple. These bikes rev very high on the freeway as they somewhat were designed to do so. First thing I did to my cb350 was go bigger on the front sprocket.
 
I know this will sound a little strange, but.... when I was a kid, I had many Honda's and it wasn't uncommon to have the speedo go out or get a project that had only a tach. My father told me after third gear the tach was basically a speedo, If I was running 5k I was running 50 m.p.h. etc... I don't think you're that far off. Like said, gear ratio could affect things, but I agree, 7k would equal 70 m.p.h. or pretty close.
 
Have you done a top speed run yet? Assuming your clutch is not slipping, if you are getting into the redline in top gear with throttle to spare, you probably need to change your gearing (sprocket sizes). However if at top speed in top gear you are below or just at redline you are probably fine.
 
Im not about to tell anyone they are wrong. Alot of guys here know a hell of a lot more than me.
360 stock is 16/34, we both got 17/34 which does smudge things a bit.
I will be real lucky to go for a ride today.
The roads are sopped, wind is gusting 25-30 and its been spitting rain. but I am gonna stay optimistic, if the roads can at least dry out, mostly.
 
Going up a tooth on the front should have the opposite effect. Rpms should be lower than with the stock configuration.
Stay safe today with those tornados brother, something we are all too familiar with here in Bama.
 
I'll leave this here.
 

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Got a little freaky here. Sirens sounding, lost power for 12+ hours, lost about a dozen shingles off garage, daughters school is cancelled today, school buses w broken windows. etc.
The forecast for Tuesday Looks good. So I am gonna take off work to fix garage roof.
That will give me time to get bike out compare my speeds.

Like I said I could be wrong...
Im remembering 60 @ 4800, 65 @5500 and 70 maybe @ 6300.
At idle my tach reads the same as my nice handheld on the crank.
My speedo is good. checked it against the subaru w cruise set to 60mph. And my tires are sized properly, front and rear.
 
Took mine out out of for a good long ride yesterday and I can verify that with 17/34 you should see somewhere between 5200-5500 at 65 mph, 5800-6200 at 70.

Stock gearing is 16/34 and that does the RPM number for the speed. So, my guess would be you have a 16 tooth front.... Numbers are dead on for it.



Trek be safe sir! That shit is crazy in your country for this time of year!
 
I got my sprockets from moto-madness in the mail a few months back and now that I think about it I never actually counted the teeth... I'll take the cover off and do a manual check

So if i want lower RPMs on the highway I want to go UP in teeth or DOWN (for the front sprocket)?
 
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