Jump to content
Sign in to follow this  

Just put my bike on a Dyno machine

Recommended Posts

So my buisness that i work for just got a Brand new Dyno Machine.

Were still working on getting it dialed in.

So i threw my 08 YZ250F on it.

Initials test: 23.5hp at 6700rpm.

Has anyone else tested their 250fs on a Dyno?

Does anyone out there know if this is pretty acurate?

Share this post


Link to post
Share on other sites

totally 100% inaccurate. I imagine you were running a knobbie?

you need to run a slick tire to get accurate results.

Share this post


Link to post
Share on other sites

The peak should be between 10k and 11k rpm. Yes, use a slick/street tire if you have one.

Share this post


Link to post
Share on other sites

ill get the name and make and year of the Dyno maching monday.

So does anybody know what the peak HP is at what RPMs

Share this post


Link to post
Share on other sites

run it up to 12k before you back it off and you garunteed to get max hp. it hits limiter at 13,500 but the hp starts to drop around 12,000.

Share this post


Link to post
Share on other sites

Doesn't hp specs change engine vs rear wheel?

Rear wheel hp might be far less than engine hp?

What is factory spec, engine or rear wheel ?

dwilkinson

Share this post


Link to post
Share on other sites

If the crank HP is ~31, 23.5 is a ~24% power loss, that seems pretty high for a lightweight dirtbike drivetrain.

Share this post


Link to post
Share on other sites
If the crank HP is ~31, 23.5 is a ~24% power loss, that seems pretty high for a lightweight dirtbike drivetrain.

not if you stick a pole in the spokes :thumbsup:

Share this post


Link to post
Share on other sites

The brand of dyno is important here, they all read differently.

Are you step testing or inertia sweep testing?

Something is strange with peak HP being produced at 6700 for sure.

Remember dyno's are tools. Used accurately before and after to measure percentage of change is optimum. One peak number from dyno "A" RARELY matches the peak number from dyno "B".

Share this post


Link to post
Share on other sites

my bike makes its peak power at 10K, going up olds hill in 3rd pinned, it went up to 11k, got knocked down to 9k and evened the rest of the way at 10k

who needs dyno's, I HAVE HILLS, haha

33hp stock is what i believe the YZ is rated at, and most places like rick peterson motor sports and other places like that show that being the baseline.

but for some reason, my bike won't hit over 12870 on my tachometer before the rev limiter kicks in, ***. I can hit 86mph stock and 93 with my 13/48 final drive.

Share this post


Link to post
Share on other sites

To know when to shift. you lose hp in the over rev. I can get 5mph more in a given distance behind my house shifting at 11k instead of the rev limiter.

it also has shift lights. tells me my engine coolant temp.

and its cool.

I have some videos of it on my myspace. myspace.com/jordanleyva add me if you please

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×