My European 102hp has more torque than an American 145hp?

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AP76ita

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Hi, I recently posted about temperature issues on my '91, still investigating.
Meantime found a 2000 American 145hp 16k miles single owner! Like new really, 6.000€ request, but after riding her I have 2 doubts, please HELP.

As soon as I purchased my '91 back in 1997, my mechanic removed carb restriction, reboring for full opening, and bike changed radically.
Can it be that the 145 has WAY LESS torque in low-mid rpm than mine?
Mine pushes since 1.500rpm like a V8! And runs up to 9k beautifully.

The 145hp swifts up to 9.5k as an f1 enginw yes, but so much quiter than mine in 1.5k-5k remember range
Is this normal?
Was the 102hp stronger in low-mid range?
Can I do something to the 145 to leave as is in high rpm and be as strong as mine in lower?

Second issue, I released gas on straight, took hands off steer (don't know correct translation sorry) and while slowing down steer started bouncing left-right-left-right always bugger movement

Owner says could be ovalized front tyre due to unusage, can this be or can be bike chassis has issues
Seeing it seems perfect

Can you help?
 

Radioguylogs

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I will let others comment about the torque of different carb configurations.

I have the same wobble when I coast down past 40 mph on my '86 Vmax with no hands on the steering. Two of my bikes do this. It seems the tightness of the steering bearings and the balance of the front tire might affect it. But those items are adjusted properly on all my bikes...
 
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I noticed the handlebar wobble when I first got my V Max. After research and a Morley expert video, I tightened the bolt for the steering head bearings and did the fall away test as instructed in Morley's video. That fixed it, and now it doesn't wobble at any speed.

 

AP76ita

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I will let others comment about the torque of different carb configurations.

I have the same wobble when I coast down past 40 mph on my '86 Vmax with no hands on the steering. Two of my bikes do this. It seems the tightness of the steering bearings and the balance of the front tire might affect it. But those items are adjusted properly on all my bikes...
So you still have the wobble on both?
 

AP76ita

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I noticed the handlebar wobble when I first got my V Max. After research and a Morley expert video, I tightened the bolt for the steering head bearings and did the fall away test as instructed in Morley's video. That fixed it, and now it doesn't wobble at any speed.


Wow Skrimps thank you. So it could be thus the issue. So strange in my '91 this doesn't happen, never, not even after a crash when a guy in a car opened his door right into my leg while I was passing through! My '91 I can leave handlebar at 150kmh and slow down until 30kmh and no wobbles, nothing.
I'm a bit afraid my mechanic won't be able to really fix this so this holds me from purchasing, together with the lowend torque missing !
 

Mr. Max

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Was the 102hp stronger in low-mid range?
What I have read about differences between these I’d say no, absolutely not. Plus you should feel extra kick at about 6k rpm on 145 hp, and it should be enough to bring smile on your face. And light up oil light.

If 102 hp feels quicker there must be some problem on 145 hp. Does it have stock exhaust? Cobra slipons are popular way to lower Vmax performance.

Carbs need cleaning too, time to time. Vboost should cycle open-close when you turn power on from key.


 

AP76ita

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What I have read about differences between these I’d say no, absolutely not. Plus you should feel extra kick at about 6k rpm on 145 hp, and it should be enough to bring smile on your face. And light up oil light.

If 102 hp feels quicker there must be some problem on 145 hp. Does it have stock exhaust? Cobra slipons are popular way to lower Vmax performance.

Carbs need cleaning too, time to time. Vboost should cycle open-close when you turn power on from key.


Correct Correct!
Kick when vboost open 6k, simile on face for how fast and smooth it jumps to 9.5k!
This vmax is really kept as new, it's a rare thing I guess, 2000, single owner, real demonstrated 16k miles only, so I really wouldn't like to loose this opportunity, but low end really disappointed me. Mine seems to be like larger displacement engine even for how it torques at very slightly throttle opening, at 2-3k
So I was wondering if maybe European also had camshafts more optimized in lower range, and/or different carbs regulations for better torque to compensate lower max hp.

Or if maybe the 145hp, apart from vboost, is also totally tuned to give its best in higher rpm

Or if its not and you experts can tell it simply should be as tough as mine in lower range, AND be as fast as it is in higher?

Exhausts are totally stock as all the bike is

I'm so wondering what to do. This bike is am opportunity, buy I would regret and miss mine's response

I know also that european has longer gear ratio, but really this 145hp seemed a smaller engine.

When I'm cruising and even slightly open throttle, seems like being bumped by a car from behind!
 

Mr. Max

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Can you take pics of both bikes final drives and send them here on forum? I reckon they have different gear ratios, there was discussion of that not so long ago.. Maybe tech experts can verify this. Longer gear ratio would definitely feel more sluggish, especially if you don't know about it :)
 

MaxMidnight

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The ratio's in the gearbox are the same for both.
Final drive ratio of the US spec is 3.667:1 (33 x 9 teeth) and the Euro is 3.300 (33 x 10 teeth)
 

AP76ita

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The ratio's in the gearbox are the same for both.
Final drive ratio of the US spec is 3.667:1 (33 x 9 teeth) and the Euro is 3.300 (33 x 10 teeth)
My bad, yes I meant the final drive.
So maybe the stronger push could be longer final, but really it's the response seems to be bigger engine
 

02GF74

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Something doesn't addup.
There is 10 % difference in gearing but 45% difference in power; and torque is related to power.
 

AP76ita

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That's why I'm freaking out
But also it's to be said that hp are pushed out proportionally to rpm being torque factor rpm.
So I bet this bike pulls them all 145 out at the proper rpm (don't know maybe 8.000, 8.500 or more)
But it's lower torque and thus response is much weaker than mine.
Even a 500hp ferrari gives those 500hp at let's say 7.750rpm but on a dyno would give maybe 100hp at around 2.000rpm so...

It would be clarifying to see 2 dyno charts for both stock European and stock American to see torque and hp at every rpm
 

AP76ita

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This is my old But tough baby
Yet previous owners from just 1991 to 1997 when I bought it, had stored her constantly outside thus wearing all the body parts this way
20210925_110136_copy_1008x567.jpg
 

MaxMidnight

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Here is a dyno printout from my bike which has a full power motor. The only difference from standard was a Dale Walker exhaust system.

Dyno-Chart-May08.jpg

And the numbers

Dyno-Printoutt-May08.jpg

You can see that the torque curve is pretty flat between 4 and 8K

I don't recall ever seeing a printout for a restricted bike or one that has been de-restricted but without V Boost.
 

AP76ita

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Thanks for pulling out these charts, yes values match how 145 should be
European has almost same torque value but peak is at lower rpm, so surely starts earlier. Mine is also de-restricted so this may explain what I experienced.

I found a very interesting document, check it!




All is 1.500rpm lower in European so less max hp but more low-end torque

So could be maybe also camshafts are smoother and more optimized for lower power band?
And/or carbs' settings?
 

MaxMidnight

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From a quick look at the parts fisch there are three different cams (prefix 1NL, 1FK and 2WF) and there are some differences by market. I note that in some examples the throttle slide is also different for the same year.
what that doesn't help with is what the actual differences are

If you feel like having a more detailed trawl have a look here.
 

Screwloose

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Thanks for pulling out these charts, yes values match how 145 should be
European has almost same torque value but peak is at lower rpm, so surely starts earlier. Mine is also de-restricted so this may explain what I experienced.

I found a very interesting document, check it!




All is 1.500rpm lower in European so less max hp but more low-end torque

So could be maybe also camshafts are smoother and more optimized for lower power band?
And/or carbs' settings?

Just thought I would add in an equation to show HP= (Torque * RPM)/ Constant , and give an example on one of Mr
MaxMidnight's dyno outputs. I'm only repeating what everyone is saying, but absolutely you are bound by equation where torque is related to power.


IMG_1526 (1).jpg
 

Screwloose

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To be clearer, I should have added in the calculations above that 2 Pi is 360 degrees rotation. I.E. consider 1 rotation of a wheel.
 

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