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No kidding. Same here. I also had a road that was about a mile long through a tunnel of trees. My GS1000 would top out 5 mph higher. :)
My bikes always ran best, coming home from the bars. :LOL:

Well, until 2nd gear went out... :)
I sold that bike w/ 88K mi. and never had any issues w 2nd gear. Sold my '89 FJ1200 w 98K, and never had issues w 2nd gear, butt heard all the horror stories. And now they're having issues w the 6 speed FJR's 2nd gear; guess Yamaha are slow learners? :ROFLMAO:
 

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Come to think of it now, one change I did make was swapping the wheels to the forged aluminum MOS wheels. With the rear wheel being 2 lbs lighter and have less rolling resistance in the bearings, I imagine that accounts for some of the power gain, but not sure how much. Now I need to do that test some day when I get a chance. Do some back-to-back runs with stock rear wheel and the forged rear wheel. I'm sure @jetpilot01 would be interested to see those results as well :)
A lighter rear wheel assembly DOES does change the indicated power on a Dynjet dyno, or any other dyno that uses a "sweep" technique versus a steady rpm to measure power. This is a moment of inertia effect.

You can also change the indicated power by changing that gear you have the bike in for the dyno run. 3rd or 4th gears give lower power readings than 5th or 6th gears. Again, this is a moment of inertia effect.

Steady-state dyno (i..e dynos that hold the engine rpm steady to get their readings) do not exhibit these MOI effects. However, acceleration on the road or track DOES result in the MOI effects, so lower MOI is indeed helpful in the rear world.

Jim G
 

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Discussion Starter · #25 ·
You can also change the indicated power by changing that gear you have the bike in for the dyno run. 3rd or 4th gears give lower power readings than 5th or 6th gears. Again, this is a moment of inertia effect.

Jim G
Gear doesn't actually affect the power curve. I've done 3rd, 4th, and 5th gear on a few bikes and there was no difference between the gears. Industry standard is generally 4th gear though for most sport bikes that have 6 gears and put out at least about 25-30 hp.

There are lots of other variables that can affect results though. Like tire pressure, position of wheel on the drum, how much weight do you put on it when you strap it down, how warmed up all the bearings are (in other words how much has the dyno been running before you start collecting data), etc.
 

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Gear doesn't actually affect the power curve. I've done 3rd, 4th, and 5th gear on a few bikes and there was no difference between the gears. Industry standard is generally 4th gear though for most sport bikes that have 6 gears and put out at least about 25-30 hp.

There are lots of other variables that can affect results though. Like tire pressure, position of wheel on the drum, how much weight do you put on it when you strap it down, how warmed up all the bearings are (in other words how much has the dyno been running before you start collecting data), etc.
On a Chevrolet SSR (the retro-design pickup truck with steel convertible roof made between 2003 and 2006), which had a 3+overdrive automatic transmission, we ran a dyno test where we tested in gears 1,2, and 3. 1 and 2 gave power results that were lower than 3rd, with 1st gear being the worst, about 5% lower than 3rd. But the jumps between gears on motorcycles are smaller, since they have 5 or 6 gears, so maybe the differences are smaller there and are missed because of other things changing at the same time.

Jim G
 

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Discussion Starter · #27 ·
On a Chevrolet SSR (the retro-design pickup truck with steel convertible roof made between 2003 and 2006), which had a 3+overdrive automatic transmission, we ran a dyno test where we tested in gears 1,2, and 3. 1 and 2 gave power results that were lower than 3rd, with 1st gear being the worst, about 5% lower than 3rd. But the jumps between gears on motorcycles are smaller, since they have 5 or 6 gears, so maybe the differences are smaller there and are missed because of other things changing at the same time.

Jim G
Ok, well that's a totally different thing lol Apples and oranges again.

But it is possible that 1st gear would give some skewed results on a motorcycle dyno too because the fast acceleration, especially on 600s or 1000s. I've only ever used 1st gear on the dyno on a Grom and a CRF300L. They both went from 3000 rpm to just before the rev limiter in about 2 seconds or less...everything happens very quick at that point.
 

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On higher HP bikes, often the power output is restricted in the lower gears, so dyno runs have to be done in a higher gear to get a true reading.
I doubt that's a factor on the 400, but I don't know for sure.
 
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SBK1198,
I have look at & test bike engines on about 5 different chassis dyno's. Not one of them had a correct SAE correction that worked. I never found one that used humidity in the calculation. I always did my own correction using a Meriam barometer, digital thermometer in the carb or throttle body, and a humidly gauge in the dyno room. Not once did it ever agree with the Dyno Jet, SuperFlow, or whatever brand dyno. At Kohler, in the engine lab, we corrected/certified the SAE correction data every morning, because our dyno runs needed to be certified to the Feds, for emissions & power ratings. The engine dyno's were eddy current pumps with highly accurate load cells that are controlled to 1 RPM, and repeatable to 5 RPM. That said, it's too bad all of us that are interested in engine performance can't find reliable/inexpensive place's to test are engines that really work.
Brian
PS, Maybe we should all get electric bikes, forget that thought.
 

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Discussion Starter · #30 ·
SBK1198,
I have look at & test bike engines on about 5 different chassis dyno's. Not one of them had a correct SAE correction that worked. I never found one that used humidity in the calculation. I always did my own correction using a Meriam barometer, digital thermometer in the carb or throttle body, and a humidly gauge in the dyno room. Not once did it ever agree with the Dyno Jet, SuperFlow, or whatever brand dyno. At Kohler, in the engine lab, we corrected/certified the SAE correction data every morning, because our dyno runs needed to be certified to the Feds, for emissions & power ratings. The engine dyno's were eddy current pumps with highly accurate load cells that are controlled to 1 RPM, and repeatable to 5 RPM. That said, it's too bad all of us that are interested in engine performance can't find reliable/inexpensive place's to test are engines that really work.
Brian
PS, Maybe we should all get electric bikes, forget that thought.
That's good to know. I have looked into the SAE correction factors before and the info I found also agreed with my test findings and what you said, that it's not 100% accurate way of normalizing dyno results, but it will bring values closer together. Still better than leaving results uncorrected, but not a completely accurate way of normalizing.

I am not opposed to electric bikes, but they need to improve the battery technology and the costs to get lower :)
 

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. . .
I am not opposed to electric bikes, but they need to improve the battery technology and the costs to get lower :)
We also need electrical infrastructure. Right now you cannot practically travel on long trips cross country, in either The U.S. or Canada, by either EV motorcycle or EV car because the charging infrastructure is so sparse and the charging times are too long.

Our EV Kia Soul works for us because our usage is mostly my wife's job commuting and the rest is local trips that very rarely exceed 90 km = 55 miles. And using the EV versus its predecessor (another Kia Soul but turbo gasoline engine), cuts our monthly "fuel" cost by about 83% (No exaggeration). But if we wanted to go cross country covering 600 miles per day, the infrastructure is currently way too restrictive. It'll happen, but it is certainly not there yet.

Jim G
 

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sbk1198,
The fact is that we should all thank Kawasaki for making a 400cc race bike, and then hanging lights and turn signals on it. If you look at the 300, and compare it to the 400, frame engine gearbox, this bike is a bargain. It's raced all over the world, it has tons of speed parts available. It just won the WSB 300/400 championship, with YSS suspension components by the way. What's not to like. For a $5000.00 bike, it handles really well. If you push it, sure it needs some new parts, but the foundation is there. If Kawasaki brought out a $7500.00 model with great forks & shocks, bigger brakes, I'm guessing that very few would buy it. We all seem to have our own ways of doing things, but that's OK, we are all on 2 wheels with a great little FAST bike underneath us..
BMHS
PS, I'm actually considering selling my 2018 Z900RS Café this Spring, because this 400 is such a HOOT to ride.
 

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Discussion Starter · #33 ·
sbk1198,
The fact is that we should all thank Kawasaki for making a 400cc race bike, and then hanging lights and turn signals on it. If you look at the 300, and compare it to the 400, frame engine gearbox, this bike is a bargain. It's raced all over the world, it has tons of speed parts available. It just won the WSB 300/400 championship, with YSS suspension components by the way. What's not to like. For a $5000.00 bike, it handles really well. If you push it, sure it needs some new parts, but the foundation is there. If Kawasaki brought out a $7500.00 model with great forks & shocks, bigger brakes, I'm guessing that very few would buy it. We all seem to have our own ways of doing things, but that's OK, we are all on 2 wheels with a great little FAST bike underneath us..
BMHS
PS, I'm actually considering selling my 2018 Z900RS Café this Spring, because this 400 is such a HOOT to ride.
Yep, it's a great little bike for sure! I have no regrets. The Z900RS is a cool looking bike too. I like the retro look but with modern technology.

By the way, you know you can just click "reply" and automatically quote a message rather than type out who it's being addressed to like a letter :)
 

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sbk1198,
The fact is that we should all thank Kawasaki for making a 400cc race bike, and then hanging lights and turn signals on it. If you look at the 300, and compare it to the 400, frame engine gearbox, this bike is a bargain. It's raced all over the world, it has tons of speed parts available. It just won the WSB 300/400 championship, with YSS suspension components by the way. What's not to like. For a $5000.00 bike, it handles really well. If you push it, sure it needs some new parts, but the foundation is there. If Kawasaki brought out a $7500.00 model with great forks & shocks, bigger brakes, I'm guessing that very few would buy it. We all seem to have our own ways of doing things, but that's OK, we are all on 2 wheels with a great little FAST bike underneath us..
BMHS
PS, I'm actually considering selling my 2018 Z900RS Café this Spring, because this 400 is such a HOOT to ride.
I have a buddy that might be interested in your Cafe 900. When you get ready to sell post up here in the classifieds.
Tracy
 
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