1990 50 hp Johnson reed valves

[Tim T.]

Hi everyone, my motor won't idle it will start and only run for a few seconds and cuts out. I have rebuilt the carbs. I have good compression (124, 126 psi) H Freight gauge so not sure if correct. Great spark (jumps 7/16 in) using spark checker. I removed carbs and intake. I can see light through a couple of reed valves. will this cause bad idling? and should I replace them with stock or composite reeds? thanks in advance Tim

 

[racerone]

If it starts and runs for a few seconds it is not a reed problem.----------What happens when you operate the manual fuel pump ?-----What happens if you push the key in when it falters ?-----How did this motor run for you last season ?

 

[Tim T.]

If it starts and runs for a few seconds it is not a reed problem.----------What happens when you operate the manual fuel pump ?-----What happens if you push the key in when it falters ?-----How did this motor run for you last season ?

I can keep it running if I keep pressing the key in to activate the primer

 

[Tim T.]

It was running great until a few weeks ago. I also had a spare fuel pump that I swapped out and still stalled.

 

[cyclops222]

2 bad fuel pumps ? Or is there avacuum in the fuel tank ? Try removing the fill cap on the fuel tank to be sure there is no vacuum.

Edit Remove sparkplugs to check if they are NOT perfectly clean.
Can you post pictures of the plug ends ?

 

[racerone]

When you push the key in ( motor running ) the electric primer VALVE opens.-----Fuel is then injected onto the intake air stream.-----This fuel bypasses the metering circuits in the carburetors.-----To me this indicates an issue with the carburetors.----Checked flywheel key ?-----Water pump impeller replaced ?------Compression test is recent or last year ?

 

[Tim T.]

2 bad fuel pumps ? Or is there avacuum in the fuel tank ? Try removing the fill cap on the fuel tank to be sure there is no vacuum.

Edit Remove sparkplugs to check if they are NOT perfectly clean.
Can you post pictures of the plug ends ?

brand new spark plugs. Tried loosening the cap first thing still stalled

 

[Tim T.]

When you push the key in ( motor running ) the electric primer VALVE opens.-----Fuel is then injected onto the intake air stream.-----This fuel bypasses the metering circuits in the carburetors.-----To me this indicates an issue with the carburetors.----Checked flywheel key ?-----Water pump impeller replaced ?------Compression test is recent or last year ?

I have not checked flywheel key. New water pump 3 months ago. Compression checked today (124, 126 psi). I will check out carbs as soon as I can and I will pull flywheel to check key. thanks for the advice Tim

 

[cyclops222]

Rare but really instantly causes your symptoms............. Watery gas load sold to you that time. Quick test for watery gas is to start at about 1/ 4 to 3/8 of the throttle opening. KEEP HAND on the throttle lever to stop excessive engine speed !!!!! If if starts and runs terrible almost every time ? Watery gas in tank & lines. Post back if crappy higher throttle opening position is runable.

 

[Michaelduf]

I have not checked flywheel key. New water pump 3 months ago. Compression checked today (124, 126 psi). I will check out carbs as soon as I can and I will pull flywheel to check key. thanks for the advice Tim

Hey Tim, I have a 2000 Johnson 50 and am going through similar issues. My carbs are good and checked multiple times. Compression at 115 in both cylinders. Spark tested good. Fuel loaded into carb bowls. Fuel line bulb is firm. my engine only starts for a few second when using the primer. My last step to check is the flywheel key.

What was your solution?

 

[saltchuckmatt]

Hey Tim, I have a 2000 Johnson 50 and am going through similar issues. My carbs are good and checked multiple times. Compression at 115 in both cylinders. Spark tested good. Fuel loaded into carb bowls. Fuel line bulb is firm. my engine only starts for a few second when using the primer. My last step to check is the flywheel key.

What was your solution?

They don't like you bringing old threads back. Also, most people don't report back from a problem over a year ago.

Start a new thread describing what is wrong and what you have read and lots of good people will reply.

It's an easy mistake it's just against TOS.

 

[ct1762@gmail.com]

Hey Tim, I have a 2000 Johnson 50 and am going through similar issues. My carbs are good and checked multiple times. Compression at 115 in both cylinders. Spark tested good. Fuel loaded into carb bowls. Fuel line bulb is firm. my engine only starts for a few second when using the primer. My last step to check is the flywheel key.

What was your solution?

at 115psi id have the cylinder head off for inspection!