40hp seahorse motor issue

[Lip Rippers]

so i had issues with the floats this spring kept flooding issue fixed and ran great after that now for the last few time i have been out i can not get more than 8 mph when i normally get around 18 when full throttle it is not missing/skipping runs like a top on the low end starts easy every time when i am trying to run full it is not over revving checked the prop seams fine i am thinking fuel issue maybe it a seahorse late 60ds anyone ever had issues like this ??

[Lip Rippers]

anyone with any ideas ?

[LongLine]

Sounds like a cylinder is not firing. Maybe a blockage?

Tom B.

(LongLine)

[Lip Rippers]

good spark on both cylinders and just replaced the plugs still same thing

[ERABBIT]

.....take cover off and see if the linkage is opening the throttle up all the way.........may just need a tweak job....

[Lip Rippers]

tweaked it abut a 1/8 inch have not had a chance to get it out but will in a hour or so let ya know if it worked or not

[ERABBIT]

........when you opened it up full did you try to see if you could open it more by hand ?

[L&M]

Adjust the high speed needle (mixture) if it's the older style 40hp carb.

[rolmops]

Adjust the high speed needle (mixture) if it's the older style 40hp carb.

What often happens with those old needles is that they vibrate loose ,so do not only adjust the needle but also make sure that it is tight in the seating or it will just happen again.

[L&M]

Adjust the high speed needle (mixture) if it's the older style 40hp carb.

What often happens with those old needles is that they vibrate loose ,so do not only adjust the needle but also make sure that it is tight in the seating or it will just happen again.

[buckboardjr]

Did you verify float hieght? This has a direct bearing on richness as well.

[Lip Rippers]

no adjustable needle jets on this one and i adjusted the linkage a lil worked pretty good then i put the cover back on and it went to hell....lol even worse than befor so i moved it back to where it was and now it is running worse yet ......................ughhhhhhh any other ideas on possible fixes the floats was replaced and set right

[rolmops]

Another thing is fuel supply.

If it does fine on the low end,but sputters as you go up,it may well be that your fuel supply is lacking.

There may be an air leak in the fuel supply hoses somewhere. The fuel pump creates a vacuum that sucks the fuel to the carbs, but if there is any place where air gets into your lines (pin holes) it will happily suck that air instead. Fuel hoses with a ball pump are infamous for that sort of trouble. You may have a clogged filter on the pickup in your tank or pump.

To check this sort of thing you can take any old bottle ,put some fuel in there and connect it to a hose that goes directly to the carb. Hold the bottle well above the engine and start her up. If she does well,you know that your carb is fine. Next, connect the hose to the fuel pump and hold the bottle well below the pump. Start her up again if she does fine again you know that your problem is farther back.If it does not ,you may have a dirty fuel filter in your pump or the pump itself has a bad diafragm, or whoever repaired the carbs did open the fuel pump and did not put everything back in the right order That way by trial and deduction you should be able to pinpoint your problem.

If on the other hand,she smokes like a fiend,you have too much fuel,which means that the float was either not seated properly,or that there is a hole in the float which causes it to fill up with fuel and sink,there by causing the engine to flood,but that should happen both at high and low rpm.

One more thing.Try to run it without the engine cover and see if it runs better, if it does your air supply is problematic and this may be caused by exhaust gas leaking out and replacing the air under the cowling.

Last thing for now,make sure that your choke (electric?) is not stuck in closed position.

It is always a very good idea to buy an ORIGINAL factory manual of your engine. Don't waste your money on a Seloc or some other inferior manual.

If none of this works for you,you may have to replace your points, but for now ,just pull both plugs and see if they are both the same color. If one is very clean,it may be time for another head gasket

Good luck.