[Drake]

I have a 2005 honda rincon 650 it runs amazing at idle but as soon as I hit around 1/4 throttle it acts like it is hitting a revlimiter and will not rev any higher It has a brand new battery I adjusted the valves with no change the diaphragm looked good it throws a tps code but that's about it the spark plug looked good I don't know if this is some sort of limp mode or what

 

[Drake]

I have narrowed it to I belive a bad cam I'm wondering if anyone sells a full topend bigbore kit with cam and all looking for a little more power if I'm doing it

 

[Ultratec]

How did you confirm this?

IMO, I would stay OEM. Any gain you get, will be marginal at best.

 

[Harley Dog]

I would check the throttle diaphragm again. I have replaced many on different bikes and ATV's. Sometimes it's just a pin prick that you can hardly see at all. Sometimes it it where it is pressed to the slide.

Also as Ultra said, how did you check the cam. Unless it is removed and mic'd out on the bench you can't really tell for sure.

 

[Drake]

So I have not checked the cam or had the motor apart yet but as far as I can tell that is likely what is causing this atleast from reading online that seems to be what they do when the cam wears down I checked the diaphragm again still seem good the machine runs great until it hits this revlimiter type thing leaving it at maybe 8 mph in first it also sometimes hard starts like the starter can barley turn over the motor I don't know if it's related

 

[Drake]

I just realized this there is no spring in the diaphram would that cause my issue

 

[Harley Dog]

It could, however I have never ran an engine without one. Either way you need to have one in there.

 

[Send it bend it mend it]

While you're putting the spring in, a common cheap and easy mod is to cut half the spring off. It improves responsiveness by allowing the slide to open faster. Just do a search on the forum for 'clip carb spring' for more details, there are dozens of threads on this.

 

[Drake]

While you're putting the spring in, a common cheap and easy mod is to cut half the spring off. It improves responsiveness by allowing the slide to open faster. Just do a search on the forum for 'clip carb spring' for more details, there are dozens of threads on this.

So do you think this would cause my rev limit issue the machine is pretty snappy up to the limiter thing

 

[Send it bend it mend it]

So do you think this would cause my rev limit issue the machine is pretty snappy up to the limiter thing

We don't know until you try, but you need a spring in there regardless so may as well put one in and see if there is any change

 

[Drake]

So I have worked on it some I ended up getting a new carb I have yet to see any change at all I put a spark plug tester that plugs in line on and it doesn't seem to be cutting ignition i may be wrong but watching the spark tester it appears that it is getting good strong spark that isn't cutting so I'm thinking I'm going to tear down the motor soon as I have to because of a leaking seal I got a new timing chain and tensioner just to replace it does anyone know what my issue may be the only other noticeable thing I have found is when it's running the akrbox lid seems to vibrate alot and when removed it makes the machine much louder

 

[Drake]

It turned out the cam lobes were worn almost completely off when I tore it down