Where did the low end torque go?

When I look at the torque curve in the manual for my 79 KZ1000st I see that it is fairly flat
about 80 kg-m at 3000 rpm with a nice little bump up to about 90 between 5500 and 7500.
Today I got a chance to wind the bike out in 3rd gear up a long steep hill and take note of how it performed at different rpm. @3000 its pretty limp, @4000 its doing OK, @ 5000 things are finally picking up, @ 6000 its pulling pretty hard, 7-9000 its a rocket, it really turns on at 7000 and will pull almost as hard at 9000.
The bike runs awesome, the top end is fresh and the carbs are clean as a whistle. It has a 1045 wiseco kit, Kenny Harmon "G" cams with 380 lift and a Mac 4-1, stock 28 carbs and airbox with K&N filter.
I did not degree the cams when I installed them ( Harmon claimed degreeing not needed because they grind their cams so accurately).
It this the way they run will a mild cam? ( I never rode it stock)

Roadflyer wrote: When I look at the torque curve in the manual for my 79 KZ1000st I see that it is fairly flat
about 80 kg-m at 3000 rpm with a nice little bump up to about 90 between 5500 and 7500.
Today I got a chance to wind the bike out in 3rd gear up a long steep hill and take note of how it performed at different rpm. @3000 its pretty limp, @4000 its doing OK, @ 5000 things are finally picking up, @ 6000 its pulling pretty hard, 7-9000 its a rocket, it really turns on at 7000 and will pull almost as hard at 9000.
The bike runs awesome, the top end is fresh and the carbs are clean as a whistle. It has a 1045 wiseco kit, Kenny Harmon "G" cams with 380 lift and a Mac 4-1, stock 28 carbs and airbox with K&N filter.
I did not degree the cams when I installed them ( Harmon claimed degreeing not needed because they grind their cams so accurately).
It this the way they run will a mild cam? ( I never rode it stock)

Stock head & carburetors will hold it back pretty good.

On my 750 twin, going to a 2-1 pipe ate up most of the low end torque. The stock 2-2 with crossover gives better low end power. I read something about how it resonates at lower RPM and gives better outflow.

Lots of basic stuff will also be a reason for low performance.
Whats your gearing?
Timing, and advancer working correctly?
Fuel: Jetting to lean or to rich, either will cause poor performance.
What is the compression, warm with the throttle held open? Good squeeze yields power.
If the cams are retarded, this will drop lower RPM power. Degreeing is a good idea.

crh wrote:

Roadflyer wrote: When I look at the torque curve in the manual for my 79 KZ1000st I see that it is fairly flat
about 80 kg-m at 3000 rpm with a nice little bump up to about 90 between 5500 and 7500.
Today I got a chance to wind the bike out in 3rd gear up a long steep hill and take note of how it performed at different rpm. @3000 its pretty limp, @4000 its doing OK, @ 5000 things are finally picking up, @ 6000 its pulling pretty hard, 7-9000 its a rocket, it really turns on at 7000 and will pull almost as hard at 9000.
The bike runs awesome, the top end is fresh and the carbs are clean as a whistle. It has a 1045 wiseco kit, Kenny Harmon "G" cams with 380 lift and a Mac 4-1, stock 28 carbs and airbox with K&N filter.
I did not degree the cams when I installed them ( Harmon claimed degreeing not needed because they grind their cams so accurately).
It this the way they run will a mild cam? ( I never rode it stock)

Stock head & carburetors will hold it back pretty good.

The bike has tons of power past 7000 rpm, I just find the bottom end a bit weak.

Motor Head wrote: Lots of basic stuff will also be a reason for low performance.
Whats your gearing?
Timing, and advancer working correctly?
Fuel: Jetting to lean or to rich, either will cause poor performance.
What is the compression, warm with the throttle held open? Good squeeze yields power.
If the cams are retarded, this will drop lower RPM power. Degreeing is a good idea.

The gearing is factory non changeable shaft drive. You would never know the low end is weak in first gear, It just blazes through the midrange to where to serious power is. The higher the gear the weaker the low end feels.

Timing advancer is working perfectly.

The bike runs perfectly and is very strong on the top end, it even gets decent fuel mileage ( just under 40 mpg) I changed the jetting when I got the bike as a non runner, 15 pilot to 17.5, stock needle moved the clip down 1 groove. main jet 105 to 115.

It has between 165 and 170 lbs compression on all 4.

I suppose I should degree the cams, I'm not sure how much difference a couple of degree's would make? (if that's all it is). When I first got the bike the intake cam was advanced 1 tooth courtesy of the bike shop that overhauled the head and did the 1045 wiseco, at that time the compression was 210-230. Timing the stock cams right dropped the compression to 185 and installing the Harmon cams put it at 165-170.

With the IN cam ahead that far, it would have made a much stronger vacuum signal= better bottom end, and response. But the upper would have suffered a bit, just how much would have to be measured. I tried that once also, set the IN cam up one tooth to see how it would go. Bottom end was real sweet, with a lot of vacuum I had the throttle valves much lower/ closed for Idle.
Lots of tuning can be done with the cams, but going with a performance grind you always have to remember its a trade off. If You get more up top, then you'll lose some down low. Compression and CC's can make up some or even all of it.

The setup on my St is as follows.

1105
stock carbs,17.5, raised needle,bigger main jet
Main portion of the air box with K/N
Untouched intake port,cleaned up exhaust.
High lift short duration cams, .395/.385 and around 266°
Degreed at 102°/108°
Ignition counter weights lightened so full advance does not happen until about 7k.
Also limited full advance to 33°.
And police exhaust,looks the same but a little more rumble.
Most of the time I'm running between 3k and 4k.
There is no need to spin it higher to stay in front of traffic.
It will pull from idle,but not like a big v-twin.
And she is better up top than stock by a little bit.

Roadflyer wrote:

crh wrote:

Roadflyer wrote: When I look at the torque curve in the manual for my 79 KZ1000st I see that it is fairly flat
about 80 kg-m at 3000 rpm with a nice little bump up to about 90 between 5500 and 7500.
Today I got a chance to wind the bike out in 3rd gear up a long steep hill and take note of how it performed at different rpm. @3000 its pretty limp, @4000 its doing OK, @ 5000 things are finally picking up, @ 6000 its pulling pretty hard, 7-9000 its a rocket, it really turns on at 7000 and will pull almost as hard at 9000.
The bike runs awesome, the top end is fresh and the carbs are clean as a whistle. It has a 1045 wiseco kit, Kenny Harmon "G" cams with 380 lift and a Mac 4-1, stock 28 carbs and airbox with K&N filter.
I did not degree the cams when I installed them ( Harmon claimed degreeing not needed because they grind their cams so accurately).
It this the way they run will a mild cam? ( I never rode it stock)

Stock head & carburetors will hold it back pretty good.

The bike has tons of power past 7000 rpm, I just find the bottom end a bit weak.

I'll bet it does exactly that. Personally, I would have advised going with the Z1 grind and and 88CFM head. Recently did a 1075 with that setup and RS34's. He's got it geared up to 16T on the front sprocket. Tons of pull through the mid range.

A pipe with smallish collector like the Vance & Hines will help the midrange, as would a rack of good carbs. The stock 28's are pretty good but they won't give you the pull that a rack of good carbs will...

The Z1 grind needs just a little bit of clearancing in the tappet bores. I can't help but feel if they were ground with 1.060" base circles they would probably fit without any grinding.

You might be fat in the middle. Try dropping the needle back to 3rd clip position since you have the airbox on it. Certainly can't hurt to try and it might just wake up the midrange I personally would pull 108 on both cams.

With your setup it should pull good down low, what is your gearing and are you trying to run it in high gear at 3000 rpms?
I have an 82 GPZ1100 bored to 1135 with high comp pistons, stock cams, ported head, RS36 carbs and a Kerker 4 into 1 pipe with the competition baffle.
Mine pulls hard from idle to redline but if I open the throttle in high gear at 3000 rpm's it will struggle. Above 5000 rpm and this thing will rip your arms off in any gear. It operates completely different than my KZ650.

baldy110 wrote: With your setup it should pull good down low, what is your gearing and are you trying to run it in high gear at 3000 rpms?
I have an 82 GPZ1100 bored to 1135 with high comp pistons, stock cams, ported head, RS36 carbs and a Kerker 4 into 1 pipe with the competition baffle.
Mine pulls hard from idle to redline but if I open the throttle in high gear at 3000 rpm's it will struggle. Above 5000 rpm and this thing will rip your arms off in any gear. It operates completely different than my KZ650.

The bike is a shaftie so the gearing is non adjustable, it turns about 4000 at 60 mph.
I do run it at about 3500 quite a bit, at that speed it doesn't really pull very hard, if I whack it open at 3500 I can feel that it takes about a second for the fuel mixture to normalize (I wish the Canadian spec bikes had the pumper carbs too!)
I have stock ignition timing right now with 92 fuel and I only get a little pinging when I first whack the throttle open at low revs when its instantaneously lean, after that it runs perfectly.