Hard Starting engine

[doubletuff43]

1990 Johnson V6 175 HP just had engine serviced Carburetors clean and adjusted also plugs change/ plug wires, 3 new battery's also timing set. Took it out last week an ran beautiful then this weekend it would not start when I put it in the water. The engine turns over an its getting fire. The fuel pressure bulb seems to take a lot of effort to get it hard and seems to go soft quickly. after cranking on it for awhile it starts and produces a lot of white smoke, kinda like it is flooded. I would appreciate any info. thanks

 

[sutor623]

Re: Hard Starting engine

Did you perform the service or did a shop do it?

 

[doubletuff43]

Re: Hard Starting engine

Shop performed work.

 

[sutor623]

Re: Hard Starting engine

Well then honestly Id say you have it made. I would bring it back up to them. If you are anxious to check a few things out I can give you some ideas to see where the issue may be stemming from.

Have you tried running the motor on flush muffs? I just say that because I have a motor that was having a hard time starting IN the water, but not on the muffs. Hell it even had issues idling IN the water, but would idle on muffs without one cough. My issue was I left the vent cap open and it rained. Also my main power wire was corroded, and it was particularly cold out, so the weak spark had something to do with it (even though it seemed like the battery was fully cranking the motor, it really wasn't) It takes a little more electricity to keep that motor spinning at idle when it is in the water.

 

[sutor623]

Re: Hard Starting engine

Sometimes after a carb job, the needles can work themselves loose since they arent being held by varnish. I know my Merc650 did that after I did a carb job on it. The low speed needle had loosened itself at WOT, and then just didnt want to start because it kept flooding the engine. Sounds like you may have the same issue...... Maybe you could (or have the shop) check the needles and all of the carb nuts and bolts.

 

[doubletuff43]

Re: Hard Starting engine

I appreciate the info. going to take it back to shop and have them re-check carbs. thanks again.

 

[sutor623]

Re: Hard Starting engine

No prob bud. Hope you figure it out. If I were you Id check the motor on muffs if you can, and maybe check compression. That way you can just rule that out. But I dont know how often you get your hands dirty. Me, I always have grease under my fingernails. If you dont wanna pay an arm and a leg, come back on here and we'll help you figure it out.

 

[emdsapmgr]

Re: Hard Starting engine

After cranking the engine for a few seconds, pull one or two of the plugs out. Are they wet or dry? That will tell you something. Make sure your fuel primer solenoid (choke) is working. Your engine is a bear to start when cold if that solenoid is not working. Pull one of the small fuel primer hoses off the very top of the top carb. Prime the fuel hose bulb, then turn the key to on, and push in on the key. You should have fuel pulsing out of the hose-that's normal.

 

[doubletuff43]

Re: Hard Starting engine

I tried the flush muffs this afternoon and she crank right up with no hesitation. On Saturday I put it in the river and the temperatures was much colder than today. I will try the fuel hose bulb. thanks for the info. P.S. I really like this forum it is very helpful

 

[sutor623]

Re: Hard Starting engine

I tried the flush muffs this afternoon and she crank right up with no hesitation. On Saturday I put it in the river and the temperatures was much colder than today. I will try the fuel hose bulb. thanks for the info. P.S. I really like this forum it is very helpful

Me too dude. This is my favorite forum for sure.

Check your main power and ground wire for corrosion. It is hard to see if they are entirely encapsulated with insulation. You can cut a small slit long-ways in the wire to inspect for corrosion. If there is no corrosion, tape it back up. I had to trace back to about 3/4 of the length of my wire to find the end of the corrosion. I cut the wire where the corrosion ended, put in a big bar clamp to tie the wire in with the fresh 4ga. wire that I bought.

After I did this, I cleaned the distributor rotor button and distributor cap. You may have a points system for your motor, I dont know. Anyhow clean up all the power wires and connections that you can get to.

Also, CHECK YOUR COMPRESSION!! Sometimes a tell tale sign that you have low compression in the motor is that it will start on muffs and not in the water.

Another tip is that when it is cold out, keep your cranking battery inside all night before a trip, and in the car on the ride. This way you will have all the cold cranking amps that you can get when you hookup to a 75 degree battery!

 

[toddschubert]

Re: Hard Starting engine

You said primer bulb had to get or stay hard. Check for air leak between bulb and tank. May be sucking air

 

[sutor623]

Re: Hard Starting engine

You said primer bulb had to get or stay hard. Check for air leak between bulb and tank. May be sucking air

True, but then he'd probably also be leaking fuel.

 

[doubletuff43]

Re: Hard Starting engine

I installed a fuel filter/ water separator on my boat made by Mercury. I took it out on the river an the motor crank right up without any hesitation, it ran beautiful with out any problems. I believe the carbs. was full of trash.
The only problem I believe I have now is the charging system is not working properly. The Tach. stop working when my starter battery died. I replaced the battery and been checking it for the last few days and notice the battery has lost charge, but my secondary battery's that controls my trolling motor is still fully charged. My new starter battery went from 12.57 down to 12.41 in a couple days. Could this be my rectifier regulator that is causing the battery to lose charge and the tachometer to stop working? P.S. when I took it to shop 2 weeks ago they check my compression. the mechanic said it test at 95 he said it was a strong running engine.

 

[emdsapmgr]

Re: Hard Starting engine

It does sound like the charging system has quit working. You are likely on the right assumption about the rectifier/regulator. A non-functional tach is usually a sign that the rectifier/regulator has quit working. Once that quits, the engine will slowly drain the battery as it runs. Since the engine makes it's own (separate) power to run the ignition, the only time the battery is used is for running the starter, the trim system and any accessories, like the radio, depth finder, lights, bilge pump, etc. It could take weeks to drain the battery to the point that it won't have enough power to crank the engine. Best to correct that charging problem before you kill a good battery.

 

[doubletuff43]

Re: Hard Starting engine

Thanks for your help. I'm going to order a rectifier regulator and try to install it myself. I think the rectifier is under the fly wheel I believe me and my brother has the tools to complete this job. I have the repair manual to follow step by step. Do you have any info. that might help me complete this job without any screw ups? Again I appreciate your knowledge and help on getting this boat in tip top shape without a mechanic costing me a fortune.

 

[emdsapmgr]

Re: Hard Starting engine

Yes, you'll have to pull the flywheel. Once you have the proper access, the replacement of the rectifier/regulator should be fairly routine. I'd make sure all of the electrical connections are cleaned up and shiny when reassembled. Esp the engine leads to the battery. Corroded battery lead terminals can be dangerous with these engines with the high capacity 35 amp alternators with the vented flywheels. The leads need to easily transfer all that current to the battery. Reduced regulator/rectifier life and excess heat buildup are averted when the leads are clamped tight to the battery. You may also want to lap the flywheel on that engine. It's a high performance engine and is easily done just prior to reinstalling the flywheel.