Before my ride today I did a few test runs up & down my road & grass.
Bike went wicked low, mid, Top end all hitting hard.
Was happy as, heading to my local beach for a few beach drags

On arrival I descovered that my bike did not run even half as well as it did at home,
once in gear it seemed rev to max revs but speed was not even half as good as at home, first I thought it must be skidding,Top speed all day in the sand would have been about 30mph.
Wasnt even throwing up any sand at all.
So I then went home jacked up the bike & floored it again, wheels spinning full speed...Im so confused.
I only live about 15 miles from the beach & my house would be very close to sea level. Temp would have been the same in both places.
Plug readings seem the same at both locations.
Also my bike will not idle also at both places.
Please help guys, Im stumped.

 

A 15 minute ride is not going to be enough of a change in altitude to affect hp much. Not unless you live on a cliff or something. You would need to change about 3000 feet of elevation to really notice it. What you have seems to be unrelated.
Even though you lost a lot of power, you should still be able to go way past 30 mph. This would just not be possible unless you were blowing out tons of black smoke and so far out of tune it barely ran.
Did you happen to suck up some water or debris that cleared up?
You did say the temp was about the same in both places right?
I have a feeling you might have a worn, loose spark plug wire, something crappy in the fuel line or whatever else could have gotten jarred lose on the ride down in the trailer.
Temporary things like this are incredibly hard to diagnose. Especially from behind a keyboard.
You might have a weak coil or stator, whatever fires these things off. I don't even know yet, but I do know cars.
If it's not air from altitude or temp changes, it's got to be fuel or spark. Chnage the gas, check the plugs and wiring, load it up and head back to test back at the beach again.

Good luck.

 

Barely legal, thanks for the reply.
Tested the bike yesterday at both locations twice with the same result,
Clean fuel was put in before first ride yesterday,
At home I was well ahead of my mates blaster,low, mid & top end.
At the beach he didnt go any higher than 3rd gear & I still couldnt keep up.
All these mods, & it is getting so unreliable.(Imagine the shame, getting blown away by a stock Blaster in 3rd gear.
Might be time to either sell up, or return to stock I think.
Aint no fun with a different prob every 2nd time I ride

 

After 2 weeks of tryin to fix this dam problem,
jetting changes,
carb cleaning, etc.
Went back & thought about what new mods have I done since this prob started, hard because I did them all at once,Wiseco,38mm Mikuni, port & new pipe, flywheel shave.
My last test was removing my mod flywheel & fitting my standerd one back in, & there it was.
Problem solved.
I dont rearly know the cause, but I can only guess there was to much taken off the flywheel resulting in no torque in the sand at all.
But on the road all the power in the world.
I had 12oz removed, Is this too much guys??