Motor Problem 90hp Mercury

[bksah2]

Thanks for all the advice I was only able to spend a little time on it today ,,I still cant rope start it just to much compression.. hooked up the battery inline with the jumpstart on my battery chager and got it to rotate a little faster so i went for more power even though the battery is in good cond. and has been load tested i went and got my truck and hot- shotted the good battery with the battery in the truck with the truck runing and finally got the motor to spin normlly so i am thinking mabe a very week starter,,,, I got it to run for about 5 seconds then she died and wont start again ,,I will check for spark tomorrow ,,,,,gas is good ,,,,, I even tryid starting fluid we will see ,,,,,,,the only other problem i will have if i get it running is how am I going to get my truck out in the middle of the bay to help with a start....

[bradford]

Sounds like a weak battery or corroded cables or connections. Be careful using that starting fluid, it doesn't have any lube oil in it.

[Kracker Jack]

Definetely watch the dry starts with ether(starting fluid). A friend of mine had a rough starting 9.9 gamefisher and he always used starting fluid to start it. premature wear on the rings due to dry starts ultimately lead to low compression and he ended up burning the motor up

[brisboats]

Yeah starting fluid is just a bad bad idea poor practice.. motor fires hard and blows the reeds the wrong way with a backfire, metal fatigue and then one day the motor may/will suck a reed through the intake. Best case is the reeds just won't seat properly and you'll replace them before you suck em. Stariting fluid is just a bad idea. PERIOD. Sounds like a weak starter/cables/arm here easy enough to fix w/o ether.

B

[bksah2]

WoW ,,here i though the starting fluid was ok to use because on the can it says it has "upper cycl. lubricants " in it.. when i first started useing starting fluid years ago i was worried about thoses same dry starts,, then when i read the can i figured that with the upper cycl. lubricants that it was made for 2cyc apps....THANKS

[spareparts]

drop the lower unit off and give it another try

[Destroyer]

I don't recall seeing ... did you check for corrosion on all your cables and connections? I'm inclined to think that the problem is electrical rather than mechanical. Reason being you said that the engine turned over fine with all plugs removed. If there was a mechanical problem then the engine would bind, with or without the plugs being in. So if we eliminate the mechanical then we are left with the electrical. That makes the prime suspect corrosion... either in the connections or in the cable itself. Easy enough to check, just run a jumper cable from your battery to the starter and try to start it. If it still binds, then you can eliminate the cables as part of the problem and move on to the next check which should be either a weak battery or a bad starter. Again, easy to check. Just remove your trucks battery and use it to replace your boats battery, then try to start it again. If it works the problem is the battery, if not, then you probably have a starter problem. (If you have one, find out what the draw is for your starter, then connect an amp meter on the cable and see how many amps you're pulling. That should tell you right away if your starter is good or bad)

[lathehand]

could it be possable your trying to start it in gear?