Reply To: Backfire/misfire thru carb

[Beno]

Ok, sea Trials are doing very well.

I started it up and it was clearly missing a cyl or more.. I ran it a few minutes and turned it off.. I got the laser-temp-shooter out, spark plug temp was 131F-131F-130F-107F deg

I pulled the colder plug and it was totally coated in 2cycle oil. (someone pu NGK polar plugs in this thing??) polar plugs are neat but once the oil pools in them. no workie!!!
clearly I’m running too much TCW3…

I had 6 gallons of 93octane in the gas tank at 30:1 mix, so I went and added 2 more gallons of straight gas at the pump, that should push it down to around 40:1

I replaced the plugs and put her in the water. I started it up, it wasn’t very happy… I kept it going with choke and high idle then got it above 3000 RPM and it suddenly took off, and left a big cloud of blue smoke behind me! off I went.

(Bonus feature today is I realized that the tachometer on the dash is functional! who would have guessed.)
More loops close to my launch trailer today, since I have a 2008 boat sticker…. I’m So paranoid of the sheriff on the water..

Max RPM seems to be attained at 5800RPM. is that sound right? feels like a rpm limiter is stopping it.
Anywhere above 4500 rpm the boat runs almost flawlessly, occasional miss (hard to hear) and Powers around and Goes like a rocket.
4000-4500 RPM: a bit erratic,kinda holds its own… rpm fluctuates and slight powerdrops off randomly tho.. within tolerance at this budget.
3000-5000 RPM: Can’t get it in this range while slowing down, it drops from 4000 right down to 2900ish… drops like a stone.
1250-3000 Rpm: not bad today.. holding it’s own.
below 1250: choppy, kickbacking. unhappy motor. stalls within a few seconds.

I freed up the ignition trigger pretty well at this point.

Ok, questions:
Whats the proper low idle rpm number?
is 5800 a good/safe top RPM?
Should I just adjust to 1250 rpm idle and be happy?