bogging/pulling issue

[Boat-ryder]

hey all,

just got a new to me fish and ski boat with 120 hp force so the family can do some ski ing,anyway problem im having is that when i first take off. the boat seems to kinda bog like im tryin to pull to much weight or something.(even with kids on tube) and it will do this for a couple yards till i get on plane then it seems to take off like it should.i dont think there is anything wrong with outboard.im wondering if weight inside the boat has anything to do with it like right now i definately have more weight in back of boat then the front.could this cause that.it does it even without pulling someone just not as bad. also have a foil on motor which should help it plane faster. thanks for any help

 

[moosehead]

Re: bogging/pulling issue

We would need boat and engine info, along with WOT RPM's and load to give you an intelligent answer.

An unintelligent guess is that you might need to prop down for a better holeshot.

 

[Natesms]

Re: bogging/pulling issue

Sounds like weight is your factor. not sure the Length of the boat but I had a 19.5 fish and ski with a 115 and it was pretty much the same way.

Putting people up front will help it plane faster for sure. That's actually pretty common practice, move everyone to the front while skiing and tubing. We used to try and keep the fuel to less than half a tank as well just to cut weight.

 

[metriccrescentwrench]

Re: bogging/pulling issue

Go for a ride by yourself and see how many rpm's the engine is turning when it's wide open (oh darn, yet another reason to go fast and have fun ). I don't know what the recommended full throttle rpm range is for your engine (look that up, you'll need to know it), you'll want to be up near the top of that range when you're boat has a light/moderate load. If your engine can't get close to the top of that range and it's in good health that's a good indication you need a lower pitched prop (which will help hole shot).

What's the maximum rated power for your boat? (Off the top of my head it seems like 120 ought to be ok for your 17 ft. Bomber.)

Are you trimming all the way in before you take off?

 

[Natesms]

Re: bogging/pulling issue

Also, I carried 2 props. 1 for skiing (hole shot) and 1 for fishing (top end). There was close to a 10 MPH difference on top end and a night and day difference on the hole shot.

It was not fun swapping props all the time though.

 

[Boat-ryder]

Re: bogging/pulling issue

ok i will try that this weekend.where could i find out the reccomended max RPMs for my motor?my prop is a 19p,your saying a 17 would have better hole shot?thanks

 

[metriccrescentwrench]

Re: bogging/pulling issue

where could i find out the reccomended max RPMs for my motor?

Best bet would be to purchase an OEM engine service manual, that and any other information you might need down the road would be in that. For a quicker answer post the question in the Force group here.

my prop is a 19p,your saying a 17 would have better hole shot?

More than likely. But with that being said it's possible to get a low enough pitched prop that you can go significantly above the manufacturers recommended rpms on your engine, in which case you'd have to pay attention and pull back the throttle before that happens. That would also limit your top speed, just like driving a 5-speed in 2nd gear.

 

[lx.crowell]

Re: bogging/pulling issue

I would add to that list in doing a compression test, it will tell you alot in if it is just a prop or if you have a dead cylinder or low compression on all of your cylinders, which on a two stroke will cause it to bog down and then ran fine on your top end. Had it happen to me on my outboard spent two months chasing fuel, electrical, exhuast just to find out it was low compression.

 

[Boat-ryder]

Re: bogging/pulling issue

i get what your sayin im not gunna run out and buy a prop just yet.guna test a few thing first. and my compreesion is all good.i really think it is a weight distribution problem but will find out this weekend.