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225 Johnson hard starting in colder temps.

G

gradywhiteman

Contributing Member
What could cause the hard starting when the temp drops into the lower 50's to upper 40's. We only get chance to use it once a week now so it sits for five days without running. To get it started I have to prime the heck out of it and the bulb(which I just replaced) never gets hard. When it finally does start it runs rough sneezes a lot and stalls until it warms up.It has one low comp. cylinder but it ran well all season. Could there be something that might contract due to lower temps to allow air into the fuel line? Also, it smokes a lot when first started.
 
If the primer bulb won't get hard on initial start up you could have some fuel lines leaking(maybe in the primer area) or carbs flooding over. Remove the hood, have somebody pump the primer bulb and check the mtr fuel system closely.
 
If the bulb does not go hard you are not building up pressure in the fuel system so there is a leak.-----------------With lack of pressure, the electric primer will not work properly when you push the key in.-----The extra smoke on start-up is quite normal.-----------Find the leak !
 
Remove the pulse line to the pump -----then sqeeze bulb and look for a leak there.---------Remove cover in front of carburetors , sqeeze bulb and look for a leak.
 
This is excellent advice....
I have a free test for you....Pump the primer bulb up as much as it will go (I know you cannot get it firm)...then
turn the red primer lever to the manual position. Pump the bulb two more times, and turn the red primer lever back to normal run position.
Try start now. If it fires immediately, which it probably will, your hard start is due to lack of proper priming, just as racerone suggests.

It could also be a bad primer bulb, leaking back and not allowing pressure to hold.

Great advice racerone and boobie.
 
Remove fuel supply hose from engine. Hold fuel primer bulb in a vertical position with outlet facing up. Pump fuel primer bulb until fuel flows. Plug fuel hose with a bolt of something of your choosing. Pump primer bulb.... it should become firm, if not, suspect that bulb valve closest to tank is faulty. Let us know what you find.
 
thanks for your replys, very helpful info. One more question, what is the pulse line? Does it feed in or out of the pump and should I plug it to test? I hope to be able to do these tests over the weekend.
 
Pulse line comes from the crankcase----------------------Positive and negative pressure pulses.------------------No fuel should leak from the pump if line is disconnected.
 
I checked the engine out today using the tests mentioned in the previous threads. I didn't see any fuel leaks at all near the carbs or at the fuel pump, I checked the pulse line for fuel when you pump the primer bulb and there was none. What I did find when I took the carb cover off was a lot of oil which leaked out of the cover and went to the engines lower area. There was also some oil in the carb cover. It started after a while still had to pump the bulb a lot, a lot of smoke, had to really open the throttle to get it to smoothe out which it did after a while. Ran it for about 15 to 20 min. at varying rpm's seemed okay but the water pump stream was cold and the fuel filter in the motor never filled more than 1/2" or so. I also noticed that the primer bulb would start to firm up after a few pumps then it would go soft, then it would firm up again and go soft again. Again this motor has one cylinder with 60# of compression a 40# difference from the highest cylinders, could this have something to do with the problem since the cold weather set in?
 
I think it is time to pull the cylinder head on the low compression cylinder and then have a look at the piston's top surface.------Post picture if you want.----I think the motor needs major work.
 
If the year of that 225hp is listed, I've overlooked it. What is it? The normal compression (what I've always encopuntered) is 95 psi on the starboard bank and 90 on the port bank.

If I read your post correctly pertaining to compression, the highest compression is 60 psi with the lowest being 20 psi??? (40 psi difference?)..... OR are you saying that the 60 psi is 40 psi below the highest reading which would be 100 psi. In any case, if either of these assumtions of mine are correct, you have a serious problem to say the least which necessitates removal of the cylinder heads for an internal inspection at a minimum. If not correct, please redo that statement about the compression.
 
Joe, the compression is 40# lower than the highest which is 100#. I just took the boat out of the water for the season today now I can pop the head off of the bad side and take a look. I would like to just do the minimum repair because of the age of the boat and motor. If the cylinder walls look okay could I just replace the rings or piston or both if needed without machining the motor other than maybe honing?
 
I understand the minimum repair thing but if the cylinder wall is scored, that'll involve some machine work, otherwise those scored will simply tear up the replacement piston. Hopefully you've just got a head gasket failing. Let us know what you discover when the head(s) come off.
 
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