Can't get top speed?

[scubart]

I am having a frustrating time with my Mercruiser/Stern Drive?
After having treated my fuel system for "Diesel Bug" I have not been able to achieve top speed. The Engine sounds sweet and all seems good but only getting 22knts at best. I have had 29/30 knts previous.
Could this be down to the treatment or something else.
I feel it is Stern Drive problem but I am open to suggestion?
Cheers all, and enjoy the weather

[jyasaki]

Is the hull clean? Try to plumb in in a small fuel tank with a fresh batch to see if it's actually (still) the fuel?

jky

[Erin]

Are you getting up to the right rpm? Did you change all filters? Could it be fuel starvation at full throttle?

[GJ0KYZ]

Originally Posted by Erin

Are you getting up to the right rpm? Did you change all filters? Could it be fuel starvation at full throttle?

Keith's right; I'd definitely check the filters.

[AMac]

Check for twisted / kinked fuel lines

[mister p]

I'd go the hull way

[thomas]

Clean hull and clean prop, we had a similar problem with a kad32, was growth on the props.