force 125 engine trouble

[89capriforce]

replaced piston on #3 cylinder put back together reusing head gasket (stupid move i know) i have done a compression test with
1 110#
2 115#
3 115#
4 115#

got spark everthing looks good but won't idle good with hose and won't idle or run in water unless i give it about 1/4 throttle. i have already ordered new head gasket. just wanted to see if anyone would think this is the problem?
i was going to do a complete rebuild this winter but if the head gasket won't fix it i think i am just going to buy a rebuilt powerhead.

 

[Jiggz]

Re: force 125 engine trouble

The compression tests are acceptable. What is your idle rpm on the muffs in neutral and also idle rpm on water in gear? You might want to check the link and synch sticky post for proper settings of idle and air screw.

 

[89capriforce]

Re: force 125 engine trouble

idle rpm on the muffs is probably around 900 the tach jumps around not very accurate. it won't idle in water at all. so needless to say just i never got to put it in gear and let it idle. if i lifted the motor out of the water i could get it to start and idle but as soon as i trimmed it all the way down it would die. also the i had to ajust the idle all the way in to even get it to idle at all. so the two lines on the throttle are are about half an inch below where the cam touches the arm.

 

[Jiggz]

Re: force 125 engine trouble

Idle rpm of 900 on muffs is a little low. Mine runs around 1100~1200 idle on muffs and around 750~800 idle in gear. Set it to this rpm for now just for troubleshooting purposes. around 1100 RPM on muffs. Verify both air screws are set at least 1 1/4 turn from lightly seated. Just for troubleshooting until you can set it to idle properly. If it still dies when you put it in the water, check for exhaust leaks from the idle exhaust relief boot. There is a rubber boot connecting those two holes (nostrils) to the exhaust and if this is leaking the engine will never idle in the water properly. If there is a tear on this rubber boot replace it. It is item #5 on this diagram.

http://www.crowleymarine.com/mercury-outboard/parts/1303_120.cfm

 

[89capriforce]

Re: force 125 engine trouble

well got to work on the boat yesterday and reset the mixture screws at 1 1/8 turns out and also reset the throttle linkage. now boat is idling 1300 on muffs. so thanks guys for all the help i just need to get it back on the water and try it out. i will let yall know.

 

[Jiggz]

Re: force 125 engine trouble

Goodluck. However if the problem persists check for exhaust leaks. You can easily tell if there is exhaust leak if the engine idles better in the water with the cowl cover remove.

 

[89capriforce]

Re: force 125 engine trouble

I did look for exhaust leaks. Last time in the water when I was having trouble I did have the cowl off and it still wouldn't start.

 

[Jiggz]

Re: force 125 engine trouble

It will very hard to check for exhaust leaks if the engine is not running to start with. But now that you have got it idling good on muffs but if it continues to idle rough in water then check for exhaust leaks. Otherwise, if it also idles good in water then there is no reason to check for exhaust leaks. Meaning you are good to go.

 

[89capriforce]

Re: force 125 engine trouble

thanks so much jiggz. you are a great help. what i was saying on my last post was that i had the cowl off while i had the boat in the water. Didn't check for exhaust leaks until you said to but that was after i had got home. again i thank you for all your help.

 

[Jiggz]

Re: force 125 engine trouble

You're welcome. Hopefully, it all works for you. Have a Happy and Safe boating.

 

[89capriforce]

Re: force 125 engine trouble

well i can get the motor to idle and start in water but it won't get over 25 mph with just me in it and only turning 3000 rpm won't go any higher. i am just stumped guys.