on my 93 88hp special seems to be running fine but gets sudden burst of power

[toddschubert]

What could cause this periodic sudden power burst that last only a second or two? I feel as though the engine is running fine then this happens and I wish it ran like that all the time. It does it at mainly higher rpms. Like 3 to 4500. I'm guessing timing or fuel but how would I tell?
I run 93 Oct w 50:1 mix and lately 1/2 can seafoam. I replaced primer bulb as that was failing and I thought it was starve for fuel but no chg.
Any ideas appreciated.
Btw 15' Larson that gets up on plane quickly

 

[petryshyn]

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

You likely have a dead cylinder that contributes now and then. What is your max RPM when planed out and wide open throttle? If its 4500 as you specified, then this is likely whats happening...

Check for spark on all cylinders....

 

[Home Cookin']

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

agreed.

 

[ncnjeremy]

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

yep, check spark, the compression, all the goodies!

 

[DargelJohn]

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

Crack open the fuel cap to eliminate the possibility of a clogged fuel vent.

 

[toddschubert]

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

Wot is 4500. All cyl fire at idle but don't like to run wot on muffs w no resistance so I don't know if power pack is failing at higher rpms. How can that be checked easily? Fuel vent is fine plugs are new and gapped according to spec. All plugs have same moist but not gooey appearance. I'm stumped

 

[toddschubert]

Re: on my 93 88hp special seems to be running fine but gets sudden burst of power

oh and compression is all within 8 PS I....112_120