Dyno Run on 68,300 Mile Tiger

[CoolHandLuke]

A local performance shop near(ish) me (GP Performance) was today doing a free bike dyno showdown to see who's bike was the fastest .

This was done free to gain more publicity for their workshop, so I shall mention their name again: GP Performance.  They were very conscientious and checked all the bikes before putting them through their paces.

I called them earlier this week and asked whether they would mind putting my Tiger on the dyno, apologising for it not being very fast, but I was curious how the engine had weathered the last 18 years and 68,300 miles.

Any way, I was pleasantly surprised to find my Tiger not only delivered more power than its original specification but also produced more than the results BOS achieved when they tested the exhaust system on whatever bike they used.

As well as confirming that the engine seems to be in good shape, they were able to tell me that the engine is running lean.  Joy, more dismantling :?.  As these carbs are from a Sprint Executive I will need to take them apart and see what jets are in ther before ordering the upgrades.

Here are the pictures.  The first, smaller picture, is from the BOS website comparing a standard Tiger with stock exhausts with a standard Tiger running with BOS exhausts.  There is no larger colour picture from what I can tell.



The second image is from todays run.

[Nick Calne]

Cool, no stray horses!  Here's to the next 68,000miles!

[CoolHandLuke]

Cool, no stray horses!  Here's to the next 68,000miles!

I'll drink to that :)

[dave NL]

80 on the wheel, nice

Numbers are promising after so many miles!   8)

[Sin_Tiger]

Absolutely brilliant  8) definately a keeper

[MtheTiger]

+1

[97tiger885]

What does "kgm" represent?  Also, what do each of the six lines(with 3 colors repeated) represent, gears 1 thru 6?

+++++
Jon

[CoolHandLuke]

What does "kgm" represent?  Also, what do each of the six lines(with 3 colors repeated) represent, gears 1 thru 6?

+++++
Jon

The different colours represent the power at the following places:

Red = Crankshaft.
Blue = Gearbox.
Green = Wheel.

The line that is mainly horizontal is torque whilst the ascending line is HP.

kgm = Kilograms force.  The bike is putting out about 75 Nm at the back wheel (green).

[97tiger885]

The different colours represent the power at the following places:

Red = Crankshaft.
Blue = Gearbox.
Green = Wheel.

The line that is mainly horizontal is torque whilst the ascending line is HP.

kgm = Kilograms force.  The bike is putting out about 75 Nm at the back wheel (green).

Thanks, now I've got it.  So, about 10% loss of HP at higher RPMs between the crank and rear wheel.  Is that typical?  And 75 Nm...not enough for the rear axle or the front sprocket nut.

[Colonel Nikolai]

THAT is impressive! It's got newborn original power! The only nit I have is that it's a 3rd party exhaust system which could be making up for some stray horses.

What kind of owner are you? Do you flog the thing when you ride? Or would you say you're completely paranoid about maintenance and drive it gently? Just curious.

Thanks for posting this.

[CoolHandLuke]

THAT is impressive! It's got newborn original power! The only nit I have is that it's a 3rd party exhaust system which could be making up for some stray horses.

What kind of owner are you? Do you flog the thing when you ride? Or would you say you're completely paranoid about maintenance and drive it gently? Just curious.

Thanks for posting this.

I am fairly laid back and mostly stay under 6,000 RPM.  I don't ride for speed, so it is only once in a while that I go anywhere near the red line.

I bought her with 35,000 miles on the clock, so how she was ridden before that is uncertain.

The contributing factors to the figures include running lean, non standard carbs, both sides of the airbox open and the aftermarket exhausts.

[Colonel Nikolai]

The contributing factors to the figures include running lean, non standard carbs, both sides of the airbox open and the aftermarket exhausts.

Good to know. Lean doesn't mean more horses though, does it?

[CoolHandLuke]

The contributing factors to the figures include running lean, non standard carbs, both sides of the airbox open and the aftermarket exhausts.

Good to know. Lean doesn't mean more horses though, does it?

It means more power as you are burning more efficiently and completely.  Too lean is really bad as the engine relies on the unburned fuels to cool and lubricate.

[CoolHandLuke]

Right, I have updated the main jets from 120-115-120 to 125-120-125.

From lots and lots of research, I think I should maintain the same economy, as the main jet only comes into play from about 60% - 100% throttle.

It wil be a few weeks before I can get back to the dyno centre and check how the change has affected the performance.

[tropicalwallah]

Hi,

Have you had a chance to dyno the Tiger with the richer jetting???
I'm running similar 125-122.5-125 settings with less restrictive pipes and air-box. I,m getting about 15km per litre with a 19 tooth front sprocket @100 kmph  using 98 octane petrol and super duper iridium plugs.

Joe