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Discussion Starter · #1 ·
I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
 

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yes it could, sumthing is up, maybe a weight in the sheave fell out of place to ,

or motor put back together wrong , lol


but if u hit 54-58 last week with belt then did motor and this week hits 45, its not the belt,
 

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I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
Depending on cam profile your clutch may not be set up correctly. Alot of times we have to stiffen up the secondary on a 686 to get back in the target rpm for HP. What color spring and weights do you have?

Nate
Alba Racing
 

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I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
If you have od weights the most likely problem is weights are not installed correctly....

Obviously you either have od weights or a sheave machined for top speed with round rollers...

If you have stock spring and lighter than stock rollers with a sheave that did 56ish before if everything was put back together correctly it would do over 60mph top speed gps...

An orange secondary spring and 16g rollers would give you 65ish...that is gps...odds are your speedo would read more...

The first thing you need to do is know if you are hitting the rev limiter or not...

Then you need to take the outer cover off your cvt and see how high the belt rides on the primary sheave in neutral when revved to the limiter...

If the belt does not go all the way to the very top of the sheave then that is your problem...it's either the primary or the wet clutch...

If that is all good then you have hp problem...motor is not making good power...that would be unlikely...most likely your primary not shifting out...
 

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Discussion Starter · #6 ·
I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
Depending on cam profile your clutch may not be set up correctly. Alot of times we have to stiffen up the secondary on a 686 to get back in the target rpm for HP. What color spring and weights do you have?

Nate
Alba Racing
Orange spring and 14g weights.
 

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Discussion Starter · #7 ·
I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
If you have od weights the most likely problem is weights are not installed correctly....

Obviously you either have od weights or a sheave machined for top speed with round rollers...

If you have stock spring and lighter than stock rollers with a sheave that did 56ish before if everything was put back together correctly it would do over 60mph top speed gps...

An orange secondary spring and 16g rollers would give you 65ish...that is gps...odds are your speedo would read more...

The first thing you need to do is know if you are hitting the rev limiter or not...

Then you need to take the outer cover off your cvt and see how high the belt rides on the primary sheave in neutral when revved to the limiter...

If the belt does not go all the way to the very top of the sheave then that is your problem...it's either the primary or the wet clutch...

If that is all good then you have hp problem...motor is not making good power...that would be unlikely...most likely your primary not shifting out...
Not hitting the rev limiter I have a programmable CDI, so likely not going to hit the rev limiter. I have a machined sheave with regular 14g weights and orange secondary spring.

I am going to take a look at the sheave and belt sometime this week. I am thinking the belt is slipping and needs to be changed. I will also check to make sure the weights are in the proper place.

When the motor was dynoed it made more horsepower and torque after the top end was done.
 

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I have a 2007 Rhino it would do 54 - 58 MPH in the sand. I had the top end redone (new pistion, rings, sleeve). The motor is a 686 with cam, ported, etc...) For some reason I have lost top end speed I can only get to 45. I am think my belt might be slipping or need to be changed.

My question is would a belt cause a loss in top end speed?
Depending on cam profile your clutch may not be set up correctly. Alot of times we have to stiffen up the secondary on a 686 to get back in the target rpm for HP. What color spring and weights do you have?

Nate
Alba Racing
Orange spring and 14g weights.

Have you had it on a dyno? Any idea what kind of power it is making?

Nate
 

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Discussion Starter · #10 ·

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The allegedly report... :biggrin:

That is funny...

If you had a weak wet clutch or slipping belt or some major malfunction you would not get very good dyno numbers...

That would go for your secondary spring and roller weight as well...

However, if your primary sheave was NOT fully shifting out and the cover was on during the dyno run it is entirely possible that they didn't realize it was not shifting out fully with low top speed and still have very good power readout...

60 is suspect relative to typical but...good power is good power...

So the question I asked earlier is still the one to answer...

Does it get to 45 REAL FAST compared to before... about the same... or slower...

If it is a real strong motor and the sheave was not fully shifting out you would have been impressed with the acceleration...

If it is a dog off the line something is way wrong between the shop's 60 rwhp dyno run and your driving it....
 

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Discussion Starter · #14 ·
Have you had it on a dyno? Any idea what kind of power it is making?

Nate
allegedly 60hp per dyno sheet.

That would be a record holding 686!!!! for reference do you know what a stock rhino baselines on that dyno?

Nate
Not sure what a stock rhino is on the dyno. Hence the word allegedly. I do know that the dyno numbers increased after the top end was done. The previous dyno numbers were 53hp.

Of course every dyno is different and I do not take the numbers as actual hp numbers.

The motor sounds good and seems to accelerate good. There is no hesitation when I nail the throttle.
 

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Discussion Starter · #15 ·
The allegedly report... :biggrin:

That is funny...

If you had a weak wet clutch or slipping belt or some major malfunction you would not get very good dyno numbers...

That would go for your secondary spring and roller weight as well...

However, if your primary sheave was NOT fully shifting out and the cover was on during the dyno run it is entirely possible that they didn't realize it was not shifting out fully with low top speed and still have very good power readout...

60 is suspect relative to typical but...good power is good power...

So the question I asked earlier is still the one to answer...

Does it get to 45 REAL FAST compared to before... about the same... or slower...

If it is a real strong motor and the sheave was not fully shifting out you would have been impressed with the acceleration...

If it is a dog off the line something is way wrong between the shop's 60 rwhp dyno run and your driving it....
It gets to 40 pretty quick then a slight hesitation for the roller flop. It appears to have good low to mid range. To me it seems like the motor has a loss of RPMs and then it catches and the RPMs seem to increase.
 
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