1985 Mercury 7.5 full speed problems

[kenrahe]

Having problems with running at high speed replaced fuel pump kit and it runs at full speed for a while then bogs down and runs shitty then dies start it back up and does the same thing again...took carb apart when first got it and cleaned bowl and jets but did not take carb completely apart...any ideas will be greatly appecated....

[El Sea]

How old is the fuel?

[kenrahe]

the fuel is about 2 months but someone told me to put a fuel addittve that he said will help the fuel pump before that didn't work so i replaced the diaphram with a fuel pump kit...also i'm not sure of the year i can't find any numbers but on the side plate of the power head it say's kiekhaefer lighting......

[pistnbroke]

when it goes shitty pump the primer bulb ..if it picks up you still have a pump problem /line blockage/tank vent ..

[kenrahe]

tried that but it does not change anything and bulb is nice and hard

[kenJ]

Might be an air leak. Check the connection where the fuel hose attaches to the engine. They eventually get loose and allow air in. Might also want to put some Seafoam into the gas. Run the engine for a while, then let it sit. Seafoam was designed to clean deposits out of carbs. The engine will smoke until the seafoam is gone.

[kenrahe]

i throughly cleaned the carb but i noticed the float is very pourous so i ordered a new one but another thing i noticed is when it's running the water seems to get hot right away an when it stalls it pop's a little through the water discharge.it's got a brand new impeller in this year....

[kenJ]

If it has a thermostat, it may be stuck. #31 in this diagram. http://www.crowleymarine.com/mercury...rts/297_80.cfm

Another possibility is you didn't get the water tube reinserted into the water pump so the engine is getting no cooling water. Are you getting flow out of the telltale?

[kenrahe]

Yes water is pumping through the powerhead but is always hot from the very start and it has no thermostat is it always hot because of being 2 stroke my 4 stroke nissanstarts out cold and always runs barley warm how can i check the reeds with the carb off i can see they are inside the powerhead and it looks like they can only be accessed by taking it apart...and how do I attach a pictur to show everyone what I'm talking about

[kenJ]

A bit confused. Looking at the '85 7.5hp manuals on the Crowley Marine site indicate all models have a thermostat. Are you sure you don't?

Are you getting water out the exhaust? Maybe something in the cooling system is plugged up.

The fact that it runs for a while would indicate to me that the reed valve is ok.

I think you have a couple things going on. One with the fuel and another with the cooling. I would get the cooling fixed first or you will end up frying the engine once the fuel problem is licked.

I run a 5hp 2 cycle. Water out the teltale takes quite a while to heat up, should be no difference between 2 cycle and 4 cycle.

[kenrahe]

how do i attach a photo and i'll send you a picture ...the person said it was and 85 but the motor says Kiekhaefer lighting on side plate and i can fin no serial number

[kenrahe]

when i try to add a photo it asks for an url not from my documents

[kenJ]

Push the add a reply button, not the quick reply.

After you type in your note, scroll down to the manage attachments button.
Push it. use the browse button at the top to find your pictures, when finished, Upload them. Max size of a .jpg is 2mb, you may need to compress them. Other formats have different sizes, there is a chart that shows.

Just saw your other note. Not sure. When I hit the browse button I get a windows explorer type window, it does not ask for an URL.

[kenrahe]

here's some pic's i think i did it right http://i1222.photobucket.com/albums/...e/DSC00414.jpg http://i1222.photobucket.com/albums/...e/DSC00412.jpg http://i1222.photobucket.com/albums/...e/DSC00413.jpg

[kenJ]

I can't open photobucket at work.

Looking at a couple of Mercury history sites, looks like the Kiekhaefer name came off the engines in the early 70's. Looks like the PO was a bit misleading.

Might want to change the title of the thread to Kiekhaefer Lightning help, there are a couple folks on the board that really know the old motors.