High speed, low rpm, bike bogs a little
 

Today while riding at high speeds I noticed that when I got to about 120 I could open up the throttle almost all of the way and my speed or RPM wouldn't really change. so i backed off and when i went to speed up again i would reach about 110 and it would do the same thing. On the way home I tried to just fight through it, but i don't want to screw up the engine or nothing. also when im just riding around town i notice that when i get to the top gear it is a very low rpm, for example, when im going about 60 i was normally around 3 1/2 rpm..and 70 i was at about 4 rpm...well now its 70 at about 3 rpm. any suggestion on what it could be?? i dont know much about bikes, and i dont really have the money to take it to the dealer, so i figured i would ask you guys and see what you all thought. well throw your suggestions at me....

thank you

Have you changed anything on the bike? Tires, sprockets, chain, anything electric?

the only thing electric i have replaced is blinker relay. i have done basic maintence to it.

that doesn't make any sense. Do you have an experienced rider around that could test it? Tell us what happens at high speed when you pull the clutch and rev it? does it change RPM normally? It must! And then, if you drop down a gear does it behave normally when you rev it? drop down another gear - now does it? If you are saying NOTHING happens, including no perceptible acceleration then i'm guessing the tach is reading correctly and the bike just isn't pulling at high loads - not much power in 6th gear at 3500 rpms and at high speed a lot of power needed - have the bike been maintained? air filter, plugs, fueling etc.

Drew was asking more about things different that might change the gearing - not electric but a different diameter tire, or different sprockets or different rear wheel that might have a different sprocket. If its not stock gearing but higher (nobody goes that way) that would result in even more engine lugging at high gears.

Finally, as I said, this bike is geared very high in 5th and 6th gear - you certainly shouldn't be shifting into 5th or 6 around town - in fact, they are almost too high for comfortably crusing at 60mph in 5th or 6th. And I don't know what happens at 100 mph in 6th when the throttle is twisted on these bikes - nothing very fast changes I'm guessing, but it should change in a gradual way.

Finally, you say you don't know much about bikes? what does that mean? If you don't know much about bikes in general, SLOW down!! or if you mean just mechanically?

+1

I've read your first post 4 times now and don't get it. Maybe I'm just not understanding the issue, but what your describing isn't really possible without having changed the gearing drastically.

I'm with you guys. I don't see how it's possible to have a bike (or any vehicle) run at the same speed at two different RPMs. Not in the same gear anyway. I'm about 75 indicated at 4000 in 6th.

i dont know about bikes mechanically, i know how to ride. i know it is odd, but thats what is happening. the speeds stay the same but the rpms have dropped about 1 to 1/2 rpms and in the same gear. no one i talk to understands it either but i will figure it out thanks.

Did you buy the bike used? Does it have a sppedohealer? If so it could cause this exact problem. If the speedohealer stopped working or got shut off...

I'll take a WAG at it...obstructed air filter or the choke not disengaging completely when the knob is pushed to off. Cheap or free to fix. Another thing to check would be the state of the ignition. Are the plugs correct, is the timing set, is the tps correctly dialed in?

When you pull the tank and the airbox to check the above, pull the spark plugs and check for a rich running condition. Also, if the gearing is not stock, 41t rear, but a 39 that would not explain the sympton.

Even with high compression pistons and sport cams, TBR exhaust, K&N etc, my VTR is calm and steady in sixth at 3.5Krpm and will pull like a freight train all the way to redline.

Considering how expensive and inept the M/C shops can be, the Honda manual and a few good quality tools will put you miles and dollars ahead in this hobby of ours.

Well, if the RPM and speed don't follow each other, one of the sensors is faulty, since it bogs a little, I'll call for a defective pulse generatoror/bad wiring for starters, if it skip pulses the ICU can't count the proper RPM and won't ignite properly
Find a multimeter with a peak hold funcion and test the PG output (close to the water pump on the front of the engine) you should have at least 0.7 V peak

Never used 6th gear until now? ;)

i think until we get a better description of what is actually happening we can't tell much of anything.