Topic: Is my k4 750 underpowered? WITH VIDEO!

[KiefRichards]

Watch from 2:00 to 3:10 where I'm wide open in 3rd gear at around 5,500 ft elevation.
That's really all she's got...

[Schnell]

On my trip around the states last summer, I really noticed a lack of power as elevation increased at various points along the way. For a while, I thought something was wrong with my bike, but it was just the thin air.

[seanbarney41]

the bike wouldn't accelerate in 4th or 5th?

[KiefRichards]

the bike wouldn't accelerate in 4th or 5th?

I honestly can't remember.
I don't watch the gauges when wringing it out,  I shift by "feel"
I guess I didn't "feel" like shifting into 4th at the time, haha.  I'm curious now, though.
FWIW, I didn't realize I was spinning it that fast, although I imagine it's fine.

Any guesses as to speed in 3rd gear with a 17/48 combo at 9000rpm?

[Garage_guy_chris]

First off im jealous we just got 12" of snow    second those are some sweet roads....

As for the bike it seems to be going pretty good. but do consider high elevations mean lower air density which in itself will reduce power but on a carbureted machine it screws up the mixture and further kills off power.  A modern fuel injected machine can at least keep the mixture under control but will still loose some from the lower air density.

[seanbarney41]

the bike wouldn't accelerate in 4th or 5th?

I honestly can't remember.
I don't watch the gauges when wringing it out,  I shift by "feel"
I guess I didn't "feel" like shifting into 4th at the time, haha.  I'm curious now, though.
FWIW, I didn't realize I was spinning it that fast, although I imagine it's fine.

Any guesses as to speed in 3rd gear with a 17/48 combo at 9000rpm?

you might want to develop your "feel" so that you shift before you run out of powerband and the onset of valve float

[KiefRichards]

the bike wouldn't accelerate in 4th or 5th?

I honestly can't remember.
I don't watch the gauges when wringing it out,  I shift by "feel"
I guess I didn't "feel" like shifting into 4th at the time, haha.  I'm curious now, though.
FWIW, I didn't realize I was spinning it that fast, although I imagine it's fine.

Any guesses as to speed in 3rd gear with a 17/48 combo at 9000rpm?

you might want to develop your "feel" so that you shift before you run out of powerband and the onset of valve float

Haha.  Whatever, I'm riding and having a blast. Hate away, I'll be riding the same spot tomorrow, still having a blast.
So, you're saying these bikes are unhappy spinning at 9k?

[seanbarney41]

the bike wouldn't accelerate in 4th or 5th?

I honestly can't remember.
I don't watch the gauges when wringing it out,  I shift by "feel"
I guess I didn't "feel" like shifting into 4th at the time, haha.  I'm curious now, though.
FWIW, I didn't realize I was spinning it that fast, although I imagine it's fine.

Any guesses as to speed in 3rd gear with a 17/48 combo at 9000rpm?

you might want to develop your "feel" so that you shift before you run out of powerband and the onset of valve float

Haha.  Whatever, I'm riding and having a blast. Hate away, I'll be riding the same spot tomorrow, still having a blast.
So, you're saying these bikes are unhappy spinning at 9k?

not hatin' bro...you just keep holdin' it wide open at 9k in third, I'll catch up with ya when come lookin' for some unbent valves, if you have trouble catchin' me, I'll be holdin' it open at 7800rpm in fifth

[Nic]

I don't understand why you kept it in 3rd at those revs?

[Retro Rocket]

the bike wouldn't accelerate in 4th or 5th?

I honestly can't remember.
I don't watch the gauges when wringing it out,  I shift by "feel"
I guess I didn't "feel" like shifting into 4th at the time, haha.  I'm curious now, though.
FWIW, I didn't realize I was spinning it that fast, although I imagine it's fine.

Any guesses as to speed in 3rd gear with a 17/48 combo at 9000rpm?

you might want to develop your "feel" so that you shift before you run out of powerband and the onset of valve float

Haha.  Whatever, I'm riding and having a blast. Hate away, I'll be riding the same spot tomorrow, still having a blast.
So, you're saying these bikes are unhappy spinning at 9k?

not hatin' bro...you just keep holdin' it wide open at 9k in third, I'll catch up with ya when come lookin' for some unbent valves, if you have trouble catchin' me, I'll be holdin' it open at 7800rpm in fifth

Exactly, I wouldn't have called that "riding by feel....? Can't you "feel" it dropping off power and needing a gear change...? You can't just keep revving it that high and expect it to continue making power...

[KiefRichards]

I don't understand why you kept it in 3rd at those revs?

Cause there were turns coming up.

What a bunch of #$%* talking pussies here

Bet you wouldn't be talking #$%* to my face

[Nic]

I don't understand why you kept it in 3rd at those revs?

Cause there were turns coming up.

What a bunch of #$%* talking pussies here

Mighty big words runt.

[KiefRichards]

I don't understand why you kept it in 3rd at those revs?

Cause there were turns coming up.

What a bunch of #$%* talking pussies here

Mighty big words runt.

Haha, runt.  Right, I promise you, you wouldn't say a peep

[Retro Rocket]

I don't understand why you kept it in 3rd at those revs?

Cause there were turns coming up.

What a bunch of #$%* talking pussies here

Bet you wouldn't be talking #$%* to my face

Looks like you are the one talking #$%* here mate...   These bikes produce peak torque at somewhere between 5-6000 rpm, sounds like your "feel" needs a tune up...Take your #$%*ed up attitude and jam it in your ass, you are the one asking the questions, if you don't like the answer, its simple, #$%* off....

[Nic]

Watch out Mick, I've already been poonced via PM from this prick.

[Retro Rocket]

Watch out Mick, I've already been poonced via PM from this prick.

Hahaha, tough guy eh....

[KiefRichards]

I don't understand why you kept it in 3rd at those revs?

Cause there were turns coming up.

What a bunch of #$%* talking pussies here

Bet you wouldn't be talking #$%* to my face

Looks like you are the one talking #$%* here mate...   These bikes produce peak torque at somewhere between 5-6000 rpm, sounds like your "feel" needs a tune up...Take your #$%*ed up attitude and jam it in your ass, you are the one asking the questions, if you don't like the answer, its simple, #$%* off....

#$%* you

I'm not jamming anything in my ass, silly faggot

[Retro Rocket]

  Happy #$%*er isn't he....

Go learn to ride properly....

[KiefRichards]

Happy #$%*er isn't he....

Go learn to ride properly....

16k posts says it all, loser

[Cabilao]

seems to become an interesting thread,i subscribe

[Nic]

Happy #$%*er isn't he....

Go learn to ride properly....

16k posts says it all, loser

9K in 3rd and you ask if your bike is under performing, who's the loser.

[Retro Rocket]

Happy #$%*er isn't he....

Go learn to ride properly....

16k posts says it all, loser

The answers you got were correct, the questions you were asked were because you stated"you ride by feel", that wasn't riding by feel, riding by feel is all about riding the torque curve to keep the bike pulling, its where its most happy, that is NOT what you were doing. the fact that you are  poor at taking feedback and resort to making petty threats to people you have no idea about, says more than anything else said here. You are the twat that got abusive, so read whats been said and suck it up princess..

[supersports400]

Maybe the bike is lazy, maybe the PO didn't rev the bike too much, maybe that way it became lazy 
Why don't you rev the bike in third longer and more often, the bike has to learn who's the master 

An modern Honda four bike easily hit's 13.000 rpm in third, and some even higher.
I don't know why Honda painted some parts of the tacho red, maybe some loser gay designer wanted to have a gay'ish accent to the bike? When I get a bike I remove the original tacho and replace it for something better, see picture, no red accent, it's black on white !

I bet the guy who overtook you (in the video) is the master of his bike, revving his bike up to 12.000 easily.

Good luck !

btw, I don't spend too much time here on the forum, see my amount of posts. I rather use the time to keep my bikes in condition, pushing them to the limit every time again. And when it's snowing, I use the dyno to keep them in shape !

[PeWe]

My bike before I tuned it needed to be maxed out on 4:th gear before shifting to 5:th, then sloooowly increasing speed

When the engine suddenly loose power in the upper rpm range, like after 8000rpm, most likely "Valve float" the situation that must not happen at all and reason for HD springs with hotter cams.
The piston will soon hit exhaust valve, possible to bend it so it will not glide in guide, piston will hit harder next time and BANG. Expensive repair.
I have revved my engine up to 9500rpm, hotter cam and HD springs with checked spring force. There is no idea to rev more than 9000rpm, not that much after 8000 either. Std engine, why bother rev more than 8000?

[JWExperience]

Seems to me the video was a "hey look at me" post rather than asking for help. I enjoyed the video for the most part and figured the bike looked pretty healthy in the first ten seconds of him accelerating. I don't think he needs mechanical help, maybe just a ego tune.


'76 cb750k, '78 cb750f 'Merica Edition