Motor setup Dhadley or anyone who knows

[caper_45ca]

I just got my motor back from the omc dealership after a rebuild....bored 30 over new pistons rings and whatever else it needed...anyway b4 I blew a ring in one cylinder the top rpm I could get out of it was 51-5200......I have a 13.75x 15 prop and all seemed to be working just fine.. satisfied with hole shot...got up on plane fairly quickly and ran about 35mph....all was good until ring broke....probable cause as suggested by folks on here was coking due to lugging.....well so history doesnt repeat itself I am posting a few pics of the setup in hopes some of you wise folks may offer some suggestions to me....the cavitation plate as u can see is approx 3/4 inch below bottom of boat.....and the rod that stops the motor from going all way in is in hole #2<br />Thank You....pics are at the following address <br /><br /> http://MotorSetup.piczo.com <br /><br /><br />I am not sure these pics went thru ..if anyone has another way of posting them pls tell me...

 

[Vic.S]

Re: Motor setup Dhadley or anyone who knows

Yes but if you get the url of each pic (Right click, goto properties and then copy and paste) and put it in your post with the image tags you can get them to appear automatically. Like this:-<br />

<br /><br />Didn't you read my reply to your earlier question or was the guide too daunting.<br /><br />Sorry though I can't help with your actual question.

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

It might help if you posted motor model#, year, hp, boat size, type, approximate weight etc. All of this info can help in determining the proper prop size, pitch, etc.

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

http://pic.piczo.com/img/i137202375_28993.jpg

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

Nice pic but it doesn't really provide much info

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

If you click on the link in the first post you should be able to see more pics which reveal more info...It is a 1985 Sportcraft 19' bowrider.......1995 90 hp Johnson..j90tleor...not sure aout total weight

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

Well the link doesn't open, Try going to Michiganwheel.com where you can provide the same info I asked for and use there prop finding tool.

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

Sorry about that link I thought it was working<br />try this <br /> http://MotorSetup.piczo.com

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

Try Michiganwheel.com

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

I used michigan wheel prop selector and it suggests 14.5x 19 prop.....I have that prop and have used it....boat seems better with the prop that is on it....anyway I am asking if my motor is setup properly..and if so then I will go the prop route...

 

[R.Johnson]

Re: Motor setup Dhadley or anyone who knows

That look's like a lot of boat for a 90. I would shoot for 6000 rpm with average load. I would think a 19" would be way to big.

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

I was thinking the same thing RJ but the pics don't give any info on boat size, length, etc. Thats why I asked for that info, also looks like motor could stand to be raised a tad maybe

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

You could try raising the motor to where the cavitation plate sits approximately 1" above the keel taking care not to raise it so far as to put the water inlets so high as to lose proper flow to the pump. Try different settings until you acheive the desired rpm's.

 

[R.Johnson]

Re: Motor setup Dhadley or anyone who knows

What HP is that boat rated for?

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

The plate on boat does not indicate rated hp...I was told that boat originally had a 4cyl inboard engine...tried to do a search on internet for that info but the boats are no longer being manufactured

 

[Dhadley]

Re: Motor setup Dhadley or anyone who knows

OK, the motor is way way too low. With that much setback we can go much higher. Stick with the same prop for now. The rod for the trim can be moved to the hole furtherest in or discarded all together since you have hydraulic trim.<br /><br />Lets get the motor up and retest. I'm really surprised you didnt have water injestion being that low.

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

Ok I will get at the boat this week and bring it up...do you suggest bringing it up to its max allowable b4 drilling new holes?.....what is water injestion?.....also it was suggested that the boat is underpowered....I was acheiving approx 35mph b4 engine rebuild..I am not too concerned with speed...my main concern is to get this thing performing at its peak efficienceyso as to not have to spend another $2400cdn on another rebuild...I was only able to get 5200rpm from it and as u have told me that is lugging that engine.....if the boat is underpowered can i still get the rpms in the 5600+ range?

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

The plate on the boat should give the length, rated capacity in persons/weight, rated hp, yr of manufacure etc. also that motor does look like it sets real low in the water.

 

[caper_45ca]

Re: Motor setup Dhadley or anyone who knows

It does..all the above but not HP.....19'...8 ppl capacity...cant remember weight...1985

 

[MCM]

Re: Motor setup Dhadley or anyone who knows

Well at any rate its rated for a whole lot more motor than whats on it, I was guessing at about 21'. Anyway like DHadley says that motors' got to get raised some.