50 hp Force Starting problems - runs great when it does start

[djsforce]

I hope you can help or give me some direction. I can get my motor running, and when it starts it runs great, idles fine and revs fine....at home in a bucket. Problem is it has only started roughly 1 in 30 tries this season. Twice when I've launched it at the lake, it would not start. Previously it has always been a quick starting motor and on my first try this season, it fired up quickly after storage. It's a 1994 Force 50 hp H050312PX. Lots of great info on this forum and this is what I've done/checked so far. Compression test is 130 psi on both cylinders. While cranking, I can see blue spark on both plugs when grounding to the cylinder head. I took the carb off and it looks nice and clean. The gas is fresh and mixed 50:1 and the bulb pumps and then gets hard. Battery is in it's second year and it cranks the motor well, I also replaced the fuel pump membrane last year. The fact that when it does start, it runs well has me thinking that the carb and fuel pump is working well. As a regular reader of this forum, I have compression, spark when I checked and the fuel system is working okay when it does run. The enricher clicks when I push the key in. I haven't tested the enricher, but it is on my to do list for tomorrow. I was thinking the enricher was the problem, but it did eventually start for me today and I ran it (in the bucket) until it was warm. When I tried to re-start warm without the enricher it wouldn't go. Any suggestions? I love this boat but it is frustrating me this season and any suggestions would be appreciated.

 

[foodfisher]

Re: 50 hp Force Starting problems - runs great when it does start

Try fresh/clean plugs on a cold start.

 

[Jiggz]

Re: 50 hp Force Starting problems - runs great when it does start

When it is cold, do you start it first with the choke on? I believe you refer to the choke as the enricher unless this is a different part of the engine. Anyways, do you press down on the key and hear the click turn to on and eventually to start while depressing?

This is how you start a cold engine. You should continue to depress and keep it starting for about 5 secs or until the engine coughs. There is little chance it might even start but most of the time the engine will cough first. After it coughs, then you can start it normally without choking and it should start. If after the first step of choking it and it did not cough, try it again for about three times.

If it still would not cough or start, you can just continue to start it normally without choking. Usually after the 2nd or 3rd time of choking the carb will already be "flooded". If it still would not start, try opening up the idle fuel-air mixture by turning CCW 1/8 turn. If it still would not start do another 1/8 turn.

If it still would not start, remove the idle mixture needle and clean the port. To put it back and set it read the sticky for the setting idle.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

Try fresh/clean plugs on a cold start.

Thanks. I didn't mention that on my first trip to the boat launch, when it wouldn't start I put new spark plugs in it. It still wouldn't start. I also found the green wire to one coil has the wire insulation missing in a few spots and had been patched with some electrical tape. Both times when I launched the boat it had been raining so I thought I discovered the problem. I added new wire, soldered it on, used liquid electrical tape and sealed it with shrink tube wrap. Starting it today, I had the same difficulty as before. Cranking it many times and it wouldn't start. When it did start once today it ran well, idled and would rev as it should. I turned it off and it would not restart.

 

[roscoe]

Re: 50 hp Force Starting problems - runs great when it does start

Check to make sure the fuel pump is mounted tight.
Maybe take it off and check the diaphragm.


Has the motor backfired?
If so, check the timing.


Then I would check remove the carb and inspect the reeds.

 

[jerryjerry05]

Re: 50 hp Force Starting problems - runs great when it does start

Did you clean the carb or just look at it for cleanliness?You didn't say??
If the enricher clicks it doesn't mean it's good.
Unhook the line to the enricher.
Turn motor over(with muffs) actuate the enricher and have someone look at the line and see if it pumps fuel.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

Did you clean the carb or just look at it for cleanliness?You didn't say??
If the enricher clicks it doesn't mean it's good.
Unhook the line to the enricher.
Turn motor over(with muffs) actuate the enricher and have someone look at the line and see if it pumps fuel.

Update from today. I checked the enricher and it did pump fuel. The fuel pump area was mounted tight, and I replaced the diaphragm just to be sure that's not the problem. When trying to start the motor it has not backfired. When cranking the motor does not cough or sputter either. On the occasions when it has started, it would do so shortly on cranking. And Jerry, when I said the carb looked clean it was just a visual that I did. So today I took the carb off again, float looked good and when I turn the carb up side down the float is horizontal. I sprayed carb cleaner in around the different areas. I even sprayed it from underneath the longer brass tube and it misted out the top hole. I'm not sure what I should be looking for with the reeds. They look like new to me. This motor has always been stored indoors in the off season and I would estimate 100 hours of total use, so it still looks like new.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

Update from today. I checked the enricher and it did pump fuel. The fuel pump area was mounted tight, and I replaced the diaphragm just to be sure that's not the problem. When trying to start the motor it has not backfired. When cranking the motor does not cough or sputter either. On the occasions when it has started, it would do so shortly on cranking. And Jerry, when I said the carb looked clean it was just a visual that I did. So today I took the carb off again, float looked good and when I turn the carb up side down the float is horizontal. I sprayed carb cleaner in around the different areas. I even sprayed it from underneath the longer brass tube and it misted out the top hole. I'm not sure what I should be looking for with the reeds. They look like new to me. This motor has always been stored indoors in the off season and I would estimate 100 hours of total use, so it still looks like new.

I put it all back together and it didn't start. No backfires and at no time did it sound like it was about to start. Out of desperation I even checked the spark again - both cylinders showed blue spark. Any advice as to what to try next? Can timing be knocked out of whack?

 

[Jiggz]

Re: 50 hp Force Starting problems - runs great when it does start

Let's assume there is good spark. So now the only thing we need to look for is fuel. Have a buddy crank it over for you while you put your hand in the exhaust snout and smell for fuel. Do you smell fuel while it's cranking over from the exhaust?

Is it weak smell of fuel or strong smell of fuel? If there's no smell of fuel, obviously we need to get fuel into the jets. Try spraying fuel-oil mix into the carb, did the engine cough? If it did, tell your buddy to crank it again while you are holding on the throttle linkage half open. If the engine starts with the throttle open, you need to clean the idle mixture port and also set the needle at least 1 1/4 turn open.

 

[roscoe]

Re: 50 hp Force Starting problems - runs great when it does start

You haven't mentioned if you are using the throttle advance while starting.


Starting procedure:

Open fuel tank vent

Check the kill switch, place in "run" position

Squeeze fuel primer bulb till firm.

Advance the throttle 3/4 way, without putting it in gear. -- This is done by either pushing a button in the center of the controls, or pulling the shift handle toward the driver, or raising the fast idle lever, all depending on what control unit you have.

Activate the choke (fuel enrichment valve) by pushing in on the key. The valve is only open while the key is being pushed in.

Turn the key to start while continuing to hold the key in.

Release the key and choke when it starts.

3-5 seconds of "choke", is usually enough.

Be ready to pull the throttle back toward the idle/neutral position, when the engine starts and the revs increase.

Continue to pull the throttle back as the engine warms up.

You should not have to use the choke much, if at all, once the engine has warmed up.

Engine should start within 10 seconds of turning the key.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

I appreciate the starting procedure and I do follow it when attempting to start the boat. I'm heading into the 7th season with this boat and all in all it's been good up until now. Tried again tonight with your suggestions Jiggz. We could smell some fuel out the exhaust but not overwhelming. The spray bottle was something new that I hadn't thought of. I tried spraying a fuel/oil mix directly into the carb and no cough or sputter. No cough or sputter with the throttle held wide open with and without spraying fuel mixture directly into the carb. And just to satisfy myself that I've done all that I can, checked one cylinder by holding the plug to the cylinder head and I could see spark. I appreciate everyone's suggestions and comments, they helped motivate me to keep at it. In my mind this motor is defying logic and I'm now considering taking it to the local marina. Not sure what more they can do

 

[Jiggz]

Re: 50 hp Force Starting problems - runs great when it does start

One more step before the Marina. Buy a see-through spark tester just to make sure you actually get spark with the plugs in. If there is no spark with plugs in it could be a weak stator voltage output caused by weak starter or cranking speed. If you have a voltage tester the output voltage of the stator at cranking speed should be at least 180VAC ~ 200VAC across one of the blue and yellow wires coming out of it and into the CD Modules.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

Great news to report - It's working again! It fired up quickly and ran great with a very minor change. I turned it off and restarted it twice with no issue. It'n now running like it used to. What did I do to it? As weird as it sounds, I put the old blackened plugs back in and it fired almost immediately. It uses L76V surface plugs. I recall a couple of years ago I put in new plugs and it wouldn't start, I put the old ones back in and it worked well again. This starting problem began when I took the boat to the launch, likely flooded it, and installed new plugs. It's only started a couple of time since the new plugs. So I have spark but maybe the current is too weak to fire a new smooth plug? I will get a see-through spark tester to see how it does. I do have a voltage tester and will check the stator. Right now I'm just basking in the glory of a running boat....without seeing a mechanic. Thanks to all for your tips and advice!

 

[roscoe]

Re: 50 hp Force Starting problems - runs great when it does start

Well, that is strange.

Glad you got it all working now.

I would go buy another set of plugs and see if they work like they should.

 

[Jiggz]

Re: 50 hp Force Starting problems - runs great when it does start

Good on you. There's still a lingering problem if it won't start with new plugs though which are better than old ones.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

I did some experimenting with the motor tonight. Local auto parts store looked at my like I had two heads when I asked if they had a see through spark tester. So I worked with what I had. I double checked from the manual that the motor does use Champion L76V plugs. With the old plugs still in it, it fired right up and ran smooth. I then tried just one new plug and left a good plug (older one) in it.- Would not start! Tried the other new plug, and it wouldn't start. It never even sounded close to starting. I put the old plugs back in and it ran well again.
Next I tried another new set of plugs straight out of the package......and it would not start. There is a difference in the colour on the writing of the spark plugs. All the old ones that work well have brown lettering, and all the new plugs that don't work (on my motor anyway) have grey lettering. I'm going to contact Champion and see if they can help, otherwise I'll be searching stores that have old inventory of plugs with brown lettering.

 

[foodfisher]

Re: 50 hp Force Starting problems - runs great when it does start

You've got a real mystery going here. Please keep us/me informed.

 

[Jiggz]

Re: 50 hp Force Starting problems - runs great when it does start

Can you post pic of the plugs. Just make sure the lettering is legible and also the face of the plugs.

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

 

[djsforce]

Re: 50 hp Force Starting problems - runs great when it does start

I hope the pictures of a new plug that doesn't work on my motor is clear enough for you. I also called the Champion technical line today. My issue was the first time they had heard of anything like it. There were no logged complaints similar to mine. There only suggestion is to try the RF plug which I will likely have to order. The technicians theory is that maybe the ignition system is creating interference that delays the spark just enough that it won't work. I'll give it a try, but I think I'll have better luck with finding old stock new spark plugs.