98 Mariner 40 fails to have full power

[Fishing Dude too]

I have a 98 Mariner, idels fine, runs up 1/2 throtle, then never picks up. Cleaned carbs, new fuel filter, checked for air leaks in fuel lines, and new plugs. Compresion tested at 115 on each cylinder. Fresh fuel, fresh oil, and checked lower unit oil (clean, and full).

 

[Maxz695]

Re: 98 Mariner 40 fails to have full power

I don,t know but if you need a stator i have one from a 97 40 HP merc 4 X 4 in great condition ,message if interested. It might be selling to a guy today. He,s converting from pull start to electric start. PN 398-832075A3 To test you stator use an ohm meter set on 1 K touch yellow to yellow it should go all the way across to 0 then touch the white green to the green white it should read from just above 1 to up to 2.5 to be in a good working range

 

[Fishing Dude too]

Re: 98 Mariner 40 fails to have full power

TY Max would but have gail force wind gust today, next chance will be thursday. From what I read that is what I was thinking just wasn't sure how. Let me know if you don't sell.

 

[Maxz695]

Re: 98 Mariner 40 fails to have full power

i just relisted it and havn,t yet heard from the guy i,ll send you the link in PM. See my other items while your there

 

[Fishing Dude too]

Re: 98 Mariner 40 fails to have full power

Wish I knew this Sat was a good day wind has been blowing yesterday and today.

 

[AndrePSP]

Re: 98 Mariner 40 fails to have full power

I have a 1990 mercury 40HP.4 cylinder, 2 carb. and I guess it does the same thing. I Had the carbs rebuilt last year, new gas tank/filter. New switchbox. motor ran like a champ.
Now, at full throtle it feels like I maybe giving it 1/3. I see alot of 'stator' mentioned. I dont understand how that affects full throtle/top speed. is that whats going on with my motor.

 

[1nebel0]

Re: 98 Mariner 40 fails to have full power

You have to check the stator and it can only be checked with a digital VOM meter and peak voltage adapter..Reading ohms will not tell you the correct story and this is stated in every factory manual...There are readings for the stator, switch box, and trigger...Stator's fail often along with switch boxes...easy to test...Stators can run you in the $250 range and factory switch boxes the same..sooooo you see that you can dump a lot of money into parts and not get the right part that is failing...good luck

 

[AndrePSP]

Re: 98 Mariner 40 fails to have full power

thanks 1nebel0.
I know the switch box was bad as it wasnt giving a spark to #3 cylinder.
thanks, Ill play with it. but it could be the stater then?

 

[1nebel0]

Re: 98 Mariner 40 fails to have full power

Yes that is why you test the stator and the switch box ...nobody knows until you run the test..let us know..

 

[AndrePSP]

Re: 98 Mariner 40 fails to have full power

going to have my buddy come out and check it out, as well as the fuel pump in case its not getting enough gas.
about 2 trips ago. its started cutting out at full throtle. In full throtle it would bog down then for a second or two start running like it should and then bog down again. now it tops out at like 10mph.
Bring Out Another Thousand.
Also, Where can I find a new fuel pump? not a kit... but a new pump

 

[AndrePSP]

Re: 98 Mariner 40 fails to have full power

It was a bad check valve in the fuel pump. ordered a new kit. taking the boat out this weekend for a fishing derby so I will see how she does.