225 Promax dies at 6000 rpm

[dondante]

Motor will shut off at around 6000 rpm and immediately crank back up and run fine. Seems like a fuel problem? Electrical would normally not crank back up after it shut down. Correct?

[whipper]

pulse pump running out of fuel? Thats were i would check first. get a kit and throw a new one in in 10min and 20 bucks. The spring wears out and cant feed the vst fast enough for the demand. Easy fix. The diaphragm might have a tear also? Plugged lines? pulse pump is the first place to look when fuel demand causes issues. 3 times this has happen to me right around that rpm. When you stop and idle it has enough to fill the vst so enough for take off. but as the demand increases you run the vst dry and no more power or fuel.

[tux974]

X2 ^, also check primer bulb when it shuts down. Always start with the simple stuff first!

[kct11]

I had that happen with a bad primer ball. Take it off, with a vst canister no season to have one. Keep it in the boat for emergency.

[vnemous]

If you can have someone pump the primer bulb at 6000 might confirm manual pump but I would just rebuild it if you havent in the past years. JMO

Oh yeah and use a mercury kit not a sierra again JMO

[kct11]

That will confirm a fuel problem. That's how I figured it was fuel, had my brother keep pumping the primer to keep it running. In my case it was a primer restriction and it was as simple as removing it.
Of course rebuilding the diaphragm pump can't hurt also if its been a while.

[dondante]

My next run I was going to relocate the primer bulb so it could be pumped. I'll check it out.

[DOC W]

whats your voltage if its over charging it will shut down also . just a thought ive had it happen had a bad regulator

[dondante]

I'll check voltage next time I go out. What's normal voltage WOT on that motor?

[tux974]

I would also change fuel line if it is old and not alcohol compatible. Definitely change it if it is grey with red lettering and I would certainly run a new Quicksilver primer bulb.

[Superbender]

why not put a vacuum gauge in line before lift pump and pressure gauge at vst to confirm issue

[vnemous]

why not put a vacuum gauge in line before lift pump and pressure gauge at vst to confirm issue


Thats what someone charging $125 an hour would do:D Happy Holidays