88 black max 200hp bad power loss/ bogging

[tommy N]

New to the forum, but have been reading it the last 6 months. Great advice and help. Ive used a bunch that I have learned here but I cant figure out my problem. <br /><br />Last few times out the boat has a bad bog/load/power loss at blast off (WOT) until on plane then ran fine at 5800-6100 rpms. The only way I can get on plane is to trim way up until rpms increase then trim back down to go.<br /><br />Ran like this the next 3 times out. Each time I checked and cleaned replaced something else on the fuel system.<br /><br />Things I’ve replaced/cleaned<br />New water/fuel separator<br />New primer bulb, checked for obstructin and air leaks in tank, hoses<br />Decarbed carbs and cylinders with seafoam/deep creep<br />Replaced plugs, impeller, thermostats<br />Head gasket leak into cylinder 5<br />After head gasket repair compression tested at 120 across the board<br />Still bogging. Pumped bulb as it was running, still bogged. Pushed in primer as running and immediately killed engine.<br /><br />I am now leaning towards electrical but how can I be sure. I am not good with electrical. Need help bad.

 

[jim dozier]

Re: 88 black max 200hp bad power loss/ bogging

Try disconnecting the fuel line and running it a short distance and report back.

 

[Wellcraft 89]

Re: 88 black max 200hp bad power loss/ bogging

I got ask the dumb ? are you sure the boat is not taking on water weight(hull leak.)does the boat stay in the water all the time?Hull fouled with crud<br />what type boat ? what prop what pitch?<br />Timing advance mechanism <br />High speed jets,fuel pump<br /><br />Rich

 

[tommy N]

Re: 88 black max 200hp bad power loss/ bogging

this is a ranger bass boat. Prop has always worked great.Has had good holeshot in the past. I believe a 23P five blade. Seems to act worse when warm.<br /><br />thanks

 

[jim dozier]

Re: 88 black max 200hp bad power loss/ bogging

Sounds like the engine may be running rich. You may have stuck open carb floats or a leaking fuel pump diaphragm. Carb rebuild or fuel pump rebuild to fix. Disconnect the fuel line at the engine and run it a short distance to see if it starts to pick up when the carbs run dry.

 

[tommy N]

Re: 88 black max 200hp bad power loss/ bogging

Where should I disconnect the fuel line at? Can this test be ran out of the water on hte pickup hose. thanks again wes

 

[jim dozier]

Re: 88 black max 200hp bad power loss/ bogging

I am assuming that your fuel line has a quick disconnect fuil line connector at the engine. When you disconnect these they should seal so no air gets in. Sometimes, if an engine is running rich, say due to stuck open carb floats or a malfunctioning fuel pump, by disconnecting the fuel line the engine will start to lean out as the existing level in the carbs goes down and the the engine will pickup and run right before it dies. Then you can start searching for the cause of the rich mixture. This procedure works better in the water when the motor is submerged and in gear under load at throttle.<br /><br />If you don't have a quick disconnect you could disconnect the line somewhere and just plug it, a little more inconvenient but doable.<br /><br />This test is simply the opposite of what you did when you pushed in the primer (or choke on an engine with chokes) which tests for a lean condition. So according to the results you got your engine isn't running lean. The fact that it is worse when it is warm also is consistent with running rich. <br /><br />None of this rules out intermittent problems with the ignition, just something to check.

 

[tommy N]

Re: 88 black max 200hp bad power loss/ bogging

Yes I can do that. I called parts for fuel pump and they wanted to sell me the whole contraption for $90. Shouldnt I begin with just the diaphragm kit? Its only $10. Isnt the diaphragm what people mean by fuel pump? thank again TWN

 

[The Marine Doctor]

Re: 88 black max 200hp bad power loss/ bogging

There should be a diaphram kit available for your fuel pump.<br /><br />TMD

 

[tommy N]

Re: 88 black max 200hp bad power loss/ bogging

I bought the diaphragm kit and a new inline filter. I want to make sure its right before I open it. 88 black max 200hp. Square fuel pump, which kit?? thanks for the help TWN

 

[tommy N]

Re: 88 black max 200hp bad power loss/ bogging

I changed fuel pump, inline filter and went to the lake. The first run was beautiful. After engine warmed up, started bogging at wot and reverse. If I tried to open it up it bogged to the point of dying. If it was bogging and I pulled it back into neutral it would die immediately. I disconnected the t connector on the gas line and right before it would run out of gas it would pick up and run good for about fifty yards before it ran out of fuel. thanks for the advice. TWN