175 mercury fail to plane out

[Drayhopper]

I have a 1995 merc 175 h that fails to come out of the hole some times. Usually the first attemp after takeing off it will lug for maybe 100 yards then take off fine. It will usually work fine for every start after this for the rest of the fishing trip.
Once it grabs and launches out of the hole, it will push my 20' skeeter at 60mph until I shut it down.
It is aggravating because it is so sporadic.

 

[Texasmark]

I had a 90 triple do just that, on most of the first of the day hole shots, regardless of winter-summer. I did find one of the CDI modules had a thermal problem in that it wouldn't fire the plug till it warmed up. I replaced it with a new one and still usually had that first shot of the day problem just not as bad. I really didn't dwell into it all that much as other than that you couldn't ask for better or more dependable power.

One thing I did notice since I had 4 props for the engine, is that if I used a lower pitch prop, like 4" down from where I like to run, it wouldn't do it. So I ported the prop I like to run, just for grins, and it helped. I think that's where the old high cube, cross flow induction system engines had it over the loopers.....they would tug and lug and the loopers like to run.....I mean when a 25 hp Johnson twin, 30 cu in block, 4500 rpm would plane out and run at a good clip, a 15' wooden, plywood boat with a couple of fishermen and all their gear and a couple of 6 gallon gas cans of gas, that's pretty good. Course you needed 2 cans of gas whereas a looper wouldn't do that but what it did it would do it with 1 can.

 

[Faztbullet]

EFI or carb motor????

 

[Drayhopper]

It is a EFI motor.

 

[Drayhopper]

I had a 90 triple do just that, on most of the first of the day hole shots, regardless of winter-summer. I did find one of the CDI modules had a thermal problem in that it wouldn't fire the plug till it warmed up. I replaced it with a new one and still usually had that first shot of the day problem just not as bad. I really didn't dwell into it all that much as other than that you couldn't ask for better or more dependable power.

One thing I did notice since I had 4 props for the engine, is that if I used a lower pitch prop, like 4" down from where I like to run, it wouldn't do it. So I ported the prop I like to run, just for grins, and it helped. I think that's where the old high cube, cross flow induction system engines had it over the loopers.....they would tug and lug and the loopers like to run.....I mean when a 25 hp Johnson twin, 30 cu in block, 4500 rpm would plane out and run at a good clip, a 15' wooden, plywood boat with a couple of fishermen and all their gear and a couple of 6 gallon gas cans of gas, that's pretty good. Course you needed 2 cans of gas whereas a looper wouldn't do that but what it did it would do it with 1 can.

I have a hard time blaming the prop because it jumps out of the hole and runs great most of the time.

 

[Faztbullet]

Check your TPS settings and MAP sensor hose for breaks or fuel filled..