1987 Mariner 40hp Occasional "Bog Out"

G

gfun21

Recruit
Joined
Dec 26, 2002
Messages
5
New carbs, new spark plugs, compression checks fine in both cylinders. New gas tank, new gas line and new female fuel connector. Ran great all day. I had the motor off for about 40 minutes while I fished and it started back up again and "bogged out" and stalled when I gave it gas. I pumped the primer ball on the gas line and tried it again and it started and ran just fine. I was wondering if the problem could have been caused by a faultering fuel pump or something else. The boat had sat for 4 years before I took possession of it and had all the work done to the motor. Although it is a 1987 Mariner I had a marine mechanic tell me the motor was built by Yamaha for Mariner.
 
H

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: 1987 Mariner 40hp Occasional "Bog Out"

The fuel pump is the first thing I'd look at. The manual for that thing might show how to test by teeing into fuel line between fuel pump and carbs and installing a pressure gauge to check fuel press. That's probably what Hooty would do.<br /><br />c/6<br /><br />Hooty
 
G

gfun21

Recruit
Joined
Dec 26, 2002
Messages
5
Re: 1987 Mariner 40hp Occasional "Bog Out"

It is a 1987 40hp-2 stroke-2 carb-oil injected model. When I pumped the primer bulb on the gas line after it would "bog out", the primer bulb was not pressurized. I was wondering if the gas line itself could be the problem since I assembled it myself from a kit and may not have tighteded everything correctly. Would it be better to look there first before I check out the fuel pump? Thank you for the link to the Mercruiser parts page! Happy Hollidays to all.
 
B

Bear

Lieutenant Commander
Joined
Mar 1, 2001
Messages
1,627
Re: 1987 Mariner 40hp Occasional "Bog Out"

Yes. If you have an air leak the fuel pump will suck air. <br />How about air vent on the gas cap. Did you close the screw while fishing? Open the gas cap next time, close it and try again. If it bogs again down after a while, open it. Some gas caps has an air vent screw on top of it. Some doesn't. <br />Make sure there is no kinch (sp?) in the fuel hose. <br /><br />Good luck!
 
G

gfun21

Recruit
Joined
Dec 26, 2002
Messages
5
Re: 1987 Mariner 40hp Occasional "Bog Out"

Happy new year to all! <br />I do have a vent on the gas cap. What is the proper protocal with the vent. Closed while running and open when sitting? Please advise and thank you guys for all the help. This forum is <br />a God-Send!
 
G

G DANE

Commander
Joined
Nov 24, 2001
Messages
2,476
Re: 1987 Mariner 40hp Occasional "Bog Out"

Hi Gfun21<br /><br />The airvent is supposed to be cloused when transportation tank, off the boat. Allwayys open when boating. Have fun
 
G

gfun21

Recruit
Joined
Dec 26, 2002
Messages
5
Re: 1987 Mariner 40hp Occasional "Bog Out"

Thank's for the advise. Going fishing in the patch reef off of Key Largo in the AM. I live in South Miami. I'll let you know how the boat ran and how many snapper and grouper I catch! Thanks once again everyone for your help!
 
You must log in or register to reply here.
Top