Help interpretting dyno with current setup.

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doodleface
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Help interpretting dyno with current setup.

Post by doodleface »

So i need some help interpreting these results if anyone knows a lot about dyno's. Heres some history.

So I recently bought an RVF400 that appeared to have some significant mods to the carbs... looks like an attempt at a HRC setup... but is missing things like all short stacks, different sized jets front n back and things like this.

Has 150 sized jets (stock 108)
Normal stacks.
Shimmed needles.
And No airbox.

Upon dynoing I think a few issues became apparent. MASSIVE rich section in the mid range, and only 54hp when stock they are 53...
All that and the extra damage to the engine from not running a filter.
With the airbox on, that wavey line almost sounded like the bike was about to shit itself. I've never experienced anything like that before in my life!

So, I bought some 115 sized jets and as a baseline to move up or down from there and try to bring it under control and want to run the airbox with out a filter,
anyone throw some light on these pics for me?

4 runs present here on graph - two brown runs nearer the 13:1 were the two 54ish HP runs.
The blue wavey line represents the airbox on run that nearly grenaded the bike.
Massively rich run was airbox with no scoop (less restrictive)
Current pipe JHA aftermarket twin pipe setup. (Left and right side pipes akimbo.)
Bottom picture shows torque / HP ... dunno but to me torque looks abysmal

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Cammo
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Re: Help interpretting dyno with current setup.

Post by Cammo »

That looks like some serious carb issues.

Are you sure everything in the carbs is standard? What code is stamped on the needles? What size pilot jets are in there? How many holes in the emulsion tubes? What is the float height set at?

Take pics of these parts (and the carbs and airbox) and post them up if you can.
"It's just a ride" Bill Hicks
doodleface
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Re: Help interpretting dyno with current setup.

Post by doodleface »

Mate i'll rip em apart piece by piece and catalogue it all for ya cause i have no idea what the guy did. Might take a few days but I could really use some help here. I'll get all those details.
James.
lizard821000
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Re: Help interpretting dyno with current setup.

Post by lizard821000 »

deffo worth ripping the carbs down and restoring the bikes set up back to standard, once thats running right, you can tune from there if you wish......

trying to sort someone elses mess by fine adjustments here and there would just take ages , check out cammos carb guide mate, best bit of reading you can do.
Neosophist
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Re: Help interpretting dyno with current setup.

Post by Neosophist »

Agree with the above, put it back to stock, maybe up the jets to 110's, 112's at a push and it should be sweet (providing you use airbox and rest of the bumf.
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