Top Speed? Picture attached!!!

[P.V.]

Re: Top Speed? Picture attached!!!

Raise the motor! From the picture you've provided, it appears that it is way too low!!! If you want speed, go up in height and think about a variety of stainless props!!

 

[hckrphil]

Re: Top Speed? Picture attached!!!

Originally posted by P.V.:<br /> Raise the motor! From the picture you've provided, it appears that it is way too low!!! If you want speed, go up in height and think about a variety of stainless props!!

Here is a closer picture of the rear end of the boat and height of the prop / engine. How high should I go? Does this look right to anyone else? <br /><br />

 

[Bob La Londe]

Re: Top Speed? Picture attached!!!

I have a 16' Jon with a 50HP Force that I get just under 30 out of with the motor currently set too deep. I bet you can get ver 40 out of that boat if the motor is set right for it.

 

[DJ]

Re: Top Speed? Picture attached!!!

DrPhil,<br /><br />That engine has the older Chrysler lower unit, not the Merc one fitted to the nearly same engine, years later.<br /><br />That is NOT an efficent lower unit/prop set up.<br /><br />You can raise it (engine) cautiously watching for water pressure changes (water pump) etc.<br /><br />Typically, fins help in planing at lower speeds. Yet, they become a hindrance at higher speeds and can cause leaning/steering issues if the engine is mounted too low.

 

[hckrphil]

Re: Top Speed? Picture attached!!!

So, judging by the picture, how much higher SHOULD the engine be mounted? Is there a standard out there? I thought I heard that the one flat part on the outdrive should be even with or a little higher than the bottom of the boat? You know, the flat thing the fin attaches to.<br /><br />~Phil

 

[Bob La Londe]

Re: Top Speed? Picture attached!!!

Originally posted by DrPhil:<br /> So, judging by the picture, how much higher SHOULD the engine be mounted? Is there a standard out there? I thought I heard that the one flat part on the outdrive should be even with or a little higher than the bottom of the boat? You know, the flat thing the fin attaches to.<br /><br />~Phil

That flat thing is called the cavitation plate. If you are going to start playing with engine height I suggest you install a water pressure gage first.

 

[Bob La Londe]

Re: Top Speed? Picture attached!!!

P.S. I'm not saying your motor is too deep. I can't tell what height it is from the picture. The rough ball park is the cavitation plate should be 1" below the bottom of the boat, but several people i have spoken with say they get their best results for speed with the plate even with the bottom of the boat.

 

[hckrphil]

Re: Top Speed? Picture attached!!!

UPDATE!<br /><br />Just got the boat in the water! After taking that damn fin off, the boat now rides PERFECTLY flat!<br /><br />With just me in the boat and 12 Gallons of gas, I had it up to just around 34MPH! Amazing, I wasn't expecting it, but it cruised NICELY!<br /><br />When I tied it up to the dock, I noticed it had a fair amount of water in the rear hatch area. I used the bilge to clean the water out and watched for a few minutes to see if the little water level increased at all. I didn't notice an increase in water height inside the boat, so I'm HOPING all is well and there isn't a leak anywhere. <br /><br />If there is a leak, I'm sure we'll see when the boat is on the bottom of the lake tomarow.... Lets hope for the best. There wasn't anything GUSHING in and I really didnt see any increase in water level once I got it pumped out, so hopefully it was just from when I rode it around the lake a little.<br /><br />Ok, thanks for everyone's comments and suggestions. I'm glad its riding straight now and I'm fairly pleased with the speed too <br /><br />~Phil

 

[williamvallotton123]

Re: Top Speed? Picture attached!!!

Hey Dcphil could i get your email address i need to talk about your boat.

 

[hckrphil]

Re: Top Speed? Picture attached!!!

Originally posted by williamvallotton123:<br /> Hey Dcphil could i get your email address i need to talk about your boat.

Sure thing!<br /><br />Haberek@gmail.com<br /><br />I'll be looking for your email.<br /><br />~Phil

 

[walleyehed]

Re: Top Speed? Picture attached!!!

We've got a 7ft'r here with a 30 Tohatsu, and all I got was grief when I asked about parts for the engine due to hydro-lock caused by excessive air time, ending in some scuba time upon re-entry.. <br />26.2 GPS is all we could flat-line with that one...

 

[eeboater]

Re: Top Speed? Picture attached!!!

Ya, but I bet it's kinda like driving a car. If you go 60 MPH in something like a Miata, versus 60 MPH in something like a 40' RV... the Miata is a bigger rush. 26.2 in a 7 ft boat has got to seem like you're going 80.<br /><br />Sean

 

[97trophy]

Re: Top Speed? Picture attached!!!

I just spoke to Mercury and the tech informed me that mercury parts were used on Force engine starting in 1992. I have a 1997 120 HP Force and he said that the gear case is a mercury only part.