need help getting more speed.

[birdgod]

Hi, i have a spectrum 1700 with 1989 force 85hp ob. it is sluminum hull.
When i go WOT, the rpm read 4500. and the speed is 31 mph according to the GPS. I read on the forums people with the same settting can get the the boat up to 40mph. I am going to do a compresstion test and are confuse with some of the steps.
1) the manual said that I have have to do the test when the engine is warm. is that right?
2) I am going to use a battery to run the starter instaed of using the key. so that I can by pass grounding the spackplug. is that ok?

 

[jerryjerry05]

Re: need help getting more speed.

Just unhook the plugs and put in the tester and have someone turn it over.
The compression should be even or close.
What prop(what prop do you have now?) and load and boat condition will have an effect on your speed.
Running with a full tank and 4 adults and 3 kids and 2 dogs will slow you down.

 

[wellsc1]

Re: need help getting more speed.

Yep, the 2 dogs is was did it! Seriously, the other boat may have been loaded less than yours. You'd be surprised how much load you add to the rig.

My boat setup happened to be the one Yamaha did. They used two people, 10 gals. fuel, and full safety equipment. When I use the boat, it has full 25 gal. tank of fuel, 2 people, 1 dog, ice chest full of drinks and ice, another ice chest half full of ice for fish, rods, reels, tackle, bait, food, rain gear, bimini deployed, and a bunch of other miscellaneous stuff just in case (oh yeah, small tool kit, first aid kit, and spare prop).

 

[birdgod]

Re: need help getting more speed.

Just unhook the plugs and put in the tester and have someone turn it over.
The compression should be even or close.
What prop(what prop do you have now?) and load and boat condition will have an effect on your speed.
Running with a full tank and 4 adults and 3 kids and 2 dogs will slow you down.

I am actually new to this, how can i tell what prop i am using? do i have to take it out to look at it?

 

[jerryjerry05]

Re: need help getting more speed.

There is a # stamped on it somewhere.It will be 15-17-19 Find this # and do the other test and post your results.J

 

[birdgod]

Re: need help getting more speed.

There is a # stamped on it somewhere.It will be 15-17-19 Find this # and do the other test and post your results.J

ok, will run the test tomorrow.