starting problems 1990 50 hp force

[caboatman]

I have just bought and installed 50 hp force. it started when I tested it before I bougt it but we didnt run it long at all because I saw it wasnt pumping water. I fixed the impeller and installed it on my boat and I have a verry hard time starting it. It cranks good and chokes well and cranks faster and faster ans sounds just on the edge of starting but most of the time it wont. when it does it will run with throttle up but dies when i slow it down. I did compression test and got 50 on both. Someone told me that wasnt enough. Also the starter gear is in the engaged position all of the time untill it finaly catches. I never had a motor that the gear didnt start off the flywheel and engage when you hit the key. Is it suposed to do that? Any help would be great Thanks.

 

[jerryjerry05]

Re: starting problems 1990 50 hp force

Redo the comp.It should be closer to 150 not 50.
No the bendix is not supposed to be engaged all the time.A bit of light grease on the worm gear under the bendix might loosen it(VERY LITTLE GREASE).
What are the rpms when you get it running?About 1200 on the hose.750-800 in the water,in gear.
Check the fuel for water.J

 

[Jiggz]

Re: starting problems 1990 50 hp force

Check the idle screw setting and also the idle mixture setting. With very low idle mixture, the engine will never fire but will sound like it's on the edge of starting until the starter disengages. As for the drive pinion not auto disengaging, fix the first before you totally damage your starter and then fix the firing problem. Start off with the idle mixture screw by turning it counter-clockwise half a turn. If it still won't fire, adjust the idle screw setting clockwise one full turn or more until you get it to run and then adjust back down until you have 800-900 rpm idle in neutral.

 

[jerryjerry05]

Re: starting problems 1990 50 hp force

Jiggs,your giving the wrong directions.The air screw is not for adjusting the idle.
The idle is adjusted by the towershaft.The air screw is for idle air mixture only.
The air screw is turned out 1 and 1/16th out and left till it's run in the water.
In the water and motor warm/running and in gear,turn the air screw in till it just starts to cough/buck stall.Then out 1/2 turn.
The idle in gear/motor warm,750-800 rpm.

 

[Jiggz]

Re: starting problems 1990 50 hp force

Jerry in a way you are correct. But if the idle mixture is set too low, even with the idle screw adjusted all the way in the engine will not fire because you are not getting enough fuel to create combustion. Adjust it a little and if there's still no combustion then go with the idle set screw. After one turn of the idle set screw and you're still not getting combustion then go back with the idle mixture screw until you get combustion. As soon as you get her running then go with the tune up for the idle mixture setting and the idle screw setting. For he needs combustion first. The fact that he mentioned that the engine fires when he holds the throttle open, it's most likely an idle mixture setting problem, why? because with throttle open you are getting more fuel from the main jets instead of the idle jets alone. Now if the engines fires but will not stay on at idle, then it's most likely an idle screw setting adjustment problem.