Not heard of similar issues.

I would, in any case, get rid of that anti-syphon valve. It is quick, inexpensive and easy to do, and even if it is not the cause, which it could be, there is nothing to lose.

Also, Check things like tank vent hose to make sure no blockages. Might not be totally blocked but a restriction could cause the issue you described. Wasps have a nasty habit of building mud nests in vent outlets.....

Have you ever used ethanol fuel in your boat? Inside of fuel lines can be destroyed by the ethanol and cause reduced fuel flow and eventually blockages. So you cant easily see the damage.

Even if no ethanol fuel has been used, fuel lines can deteriorate over time. You could consider replacing all fuel lines from tank to engine, or at least to the fuel primer bulb. Most likely the lines from the bulb to the engine are new.

One final thing - did you check to be 100% sure that your batteries are rated high enough for the Suzuki as per recommended CCA in owners manual? All charged up, in good condition? These EFI and computr controlled motors like a good strong voltage supply, if they dont get it they dont play nicely.

Just a comment - a fair percentage of problems that we see reported here in the forum turn out to be installation, electrical and fuel supply issues. Not Suzuki problems. And as you may have gathered from my suggestions, i think theres a decent chance your issues lie with your boat's fuel system.

So dont throw the baby out with the bathwater, just yet!!

If the issue persists after the above potential solutions have been investigated, I would be asking the dealer to check fuel pressure - get them to get a gauge on it and make sure all fuel pressures are up to spec.

Lastly, I am far from expert at Bass boats, but I would not have thought that a 4 blade prop would be the first choice?? They are not usually known for top end speed.....

Maybe get the current issue sorted, then talk to someone who is expert on propping Suzuki's on Bass Boats and see what prop suggestions they have.

Thanks for responding.
All your suggestion have been tried. Suzuki Tech has looked at motor but that day we could not duplicate issue. Checked fuel pressure. He suggested anti-syphon valve and new bulb. Done. I bought Odyssey battery 1100 CCA which replaced Optima Blue Top. I have not used ethanol fuel in this boat for at least six years, except for a have to situation, no premium. Lines have been changed. As far as prop goes its recommended by Suzuki for this motor. Does ok 72mph top in cool temps 63 in summer with two people 69 one person.
When pressure gauge was hooked up needle bounced couple of times on take off but read fine rest of time.
Tim

Performance 250ss

I wish I could match your performance. I have the same motor on a 20 ft. renegade flats. Suzuki prop 14.5 x 26 4 bl. I'm in the low 50's only at 5600rpm. Strong midrange power. The prop gives a a lot of stern lift which restricts my trim angle. Starts to get unstable. Thinking about getting a three blade. Is your prop a Suzuki? Would love to find a dealer in sw Florida to dial it in.

Yea get a lot of bow lift, I raise motor on hydraulic jack plate when boat gets loose. Seems to help. Prop is Suzuki SS 4 blade.
Spun the hub 3 weeks ago , running 29p now.

250ss

I'll try that to see if it helps. How is your water temp when running hard?

148 to 154 degrees. Water temp upper 80's. It doesn't take much, just a bump or two up on jack plate. Decrease the bite on prop.

My problem is stern lift from the Zuk 4 bld. prop. Would raising the JP take me more out of the water? When I trim the boat is only running on the pad and starts to push the water temp up.

I raise motor up with jack plate not trim. That lets boat down into water just enough to settle your boat back down. It gets a little light with the lift you get from that prop. In smooth water its ok but in boat wakes not so good. My boat is heavy, yours has a different hull than mine and may respond differently. Just keep playing with it and you will figure it out.

Interesting. Going to try it out next week after I service and wax the boat. Thanks

More test

I got prop back with new hub pressed in. Did short break in as instructed.
Started up, ran at full throttle for 30+/- seconds, broke loose again. Back to shop.
As far as motor dying problem, Suzuki Tech and I went out yesterday and first take off
motor died. Pressure gauge showed 0 pressure in fuel line on top of motor. He pumped
bulb 10 times before it pulled up pressure in bulb. Took a lot of data from 5 temp sensors
and two pressure gauges during trip. Just have to wait and see if data helps to find solution.