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Discussion Starter #1
Why are engines dyno'd before they leave the shop?

Every dirtbike, road bike, car I have ever had engine work done on is dyno'd with the results sheet in hand prior to taking home. And anyone who has been at a dyno-tune knows exactly how engines are ragged on with huge fans blowing into the engine bay.

Wouldn't this go against everything outlined in proper engine break in?
 

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there is a difference between a 30 second to 1 min pull on a dyno and someone rolling off the show room floor and beating the snot out of it WOT for hours on end. common sense is whats needed, and sadly most people lack any so they say to be be easy on it to guide the masses.

if there was no such thing as breakin then why do you find so much crap in the first change of the motor, trans and diff fluid? first few hours vary the rpms and avoid over 1/2 throttle, after that change the fluids and ride it, just try to avoid prolonged WOT or excessive idling.
 

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Here we go.....


:popcorn:
 

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I vary the throttle a lot during the first few hours and might go all out for a second or two, but I dont do WOT top speed runs. I do this for a few hours and then change all the fluids myself (all diffs, oil, filters, etc) and then run it exactly as I would any other machine.

On every new wheeler I had (I have only bought brand new), the amount of junk in the fluids after a few hours was quite a bit (metal shavings, etc from gears meshing and the machining process I bet?). Also, all the diffs have been quite low from the factory. Another reason I change them all myself and that way I know what is in there. YMMV
 

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Where do you live??? I'm 55 and I have never had a bike/quad/car/truck dyno'd. The first one didn't show up around here until about 20 yrs ago. And that was at one of the motorcycle shops.
 

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Discussion Starter #6
Where do you live??? I'm 55 and I have never had a bike/quad/car/truck dyno'd. The first one didn't show up around here until about 20 yrs ago. And that was at one of the motorcycle shops.
PA. Cars, bikes dyno'd here everyday. :veryhappy:
 

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Why are engines dyno'd before they leave the shop?

Every dirtbike, road bike, car I have ever had engine work done on is dyno'd with the results sheet in hand prior to taking home. And anyone who has been at a dyno-tune knows exactly how engines are ragged on with huge fans blowing into the engine bay.

Wouldn't this go against everything outlined in proper engine break in?
Your comparing apples to oranges. Any band new engine (not rebuilt) being in a car, atv, bike, crate engine, etc. has not been rebuilt by someone with their own idea's and what is better for a typical situation or combination in there minds, and has never been on an engine dyno before (Yes im sure there test engines have, but not the ones any of us have). Major manufacturers engines are built to spec and 9 times out of 10 last a LOT longer than "professionally rebuilt" engines. Therefore when you buy a new car, atv, even a manufacturers(chevy/ford) crate engine they have a recommended break in procedure. Some one that rebuilds/modifies engines will dyno for peak performance as every combination is usually different, plus they want to make sure the thing dont blow up.
 

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What's the goal? Racers is to produce top HP possible at all costs. So they build it then take it out to a race and go balls out. Is their main goal long term usability or do race engines last for years ? No

Manufactures of consumer goods and those consumers have a main goal of long term reliability and years of use.

It's pretty simple really.
 

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Discussion Starter #10

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Discussion Starter #11
I completely understand the benefits of properly breaking in an engine.
And was honestly not trying to rehash another "Break it in as you are going to ride it" thread.
I just sincerely always wondered if it was detrimental to having my 'toys' dyno'd prior to pick up. My first Harley that had engine work, they dyno'd several times to massage some additional hp out of it.
Oddly, the engine blew a year later. hmm...
 
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