No start.

[sogood]

Today I finally got everything buttoned down on my boat in preparation for starting her up after a "rest" of just over a year. She started and ran when I bought her in April 2016 and I've been busy overhauling, refurbing, refitting etc. since then, as time allowed. I'm surprised it ran at all, considering the amount of gunk in the fuel lines and the very corroded state of much of the ignition system. The coil was a rusty mess as were the terminals on the plug leads. The fuel pump was likewise gummed up and the carb wasn't much better. But still, it fired into life with no bother and ran sweetly. Not so today though!

​New fuel pump, water separator, thermostat, plugs, plug leads, coil, ignition switch, all fuel lines cleaned out, carb cleaned up and overhauled, float set, and anything else you can think of. Today I gapped and fitted the new plugs, having first sprayed the cylinders with fogging oil and turned the engine a few times. Triple checked my new plug leads were all in the right places. Set up a remote tank and primer bulb and squeezed until it was good and hard, filling the water separator in the process. Muffs fitted and hose turned on and we are good to go, but we didn't!

​The engine turned over, but slowly, not spinning as it would in my car. I suspected the battery and replaced it with the equally heavy one from my car. It normally spins my 4.0 litre with ease. But still the engine turned slowly, maybe marginally better though. I even hooked up both batteries, jumpered together, no joy.

​I sprayed some starting fluid into the carb and all that achieved was an enormous backfire. I detected a slight hiccup once or twice, like as though it was almost attempting to fire, but no joy. As I write, the battery is on charge, just to give it every possible chance.

​I cracked open the fuel line at the carb and I do have petrol getting to it. I pulled one of the plugs and found it to be smelling of fuel also, so tomorrow I'm going to verify that I have a good spark, but aside from that, does anybody have any tips / suggestions?

​Possible issue with the shift interrupt switch, as I had it off when adjusting the shift cables? I tried starting while leaving the throttle in the neutral position, and at throttle slightly open and at full open. Pumping and not pumping throttle, every possible permutation I could think of...............

​So, any thought most appreciated, including the best/safest way to check that I have a spark. Disconnect a plug lead and "ground" it, with a small enough gap to see the spark?

Thanks in advance.

 

[ThomW]

Definitely try it with a fully charged battery. Even with another issue, it should be cranking at a pretty good clip. Make sure all grounds are clean and tight.

A gap tester is best way to check spark, as you want to test spark at an almost 7/16 gap, but if you don't have one you can wrap wire to each plug and ground them to motor with alligator clips, to see if there is spark. As with anything, be very careful with sparks and fuel vapors!

Did you do anything that may have affected the motors timing? Change distributor, points, ignition coils? Did you check the ignition parts on your motor? Is this the Merc 5.7?

 

[sogood]

Thanks for the response. The battery was on charge all evening (Irish time) until tonight and is now fully charged. I intend to go over all relevant terminals and connections tomorrow before trying it again. Didn't do anything to or with the timing, just cleaned up the dist cap, which was a replacement by the PO. The dist doesn't have points ( Thunderbolt 4 ) and I replaced the single coil as part of the overhaul. Yes, it is the Merc 5.7. Thanks again, will update.

 

[Bondo]

. I intend to go over all relevant terminals and connections tomorrow before trying it again.

Ayuh,.... 'n don't forget the Grounds,.....

If the starter don't turn Briskly then, I'd pull it, 'n see why,....

 

[harleyman1975]

I am thinking either a tired starter or a bad "earth" (used to own a triumph). she starter can be rebuilt or replaced but it must be a marine rated unit if replaced. this is a "negative earth" system. (unlike the lord of darkness).

 

[Bondo]

(unlike the lord of darkness).

Ayuh,.... Lucas Electrics,.....

The lights always work, til it gets dark out,....
The wipers always work, til it rains,...
The heater always works durin' the summer,.... Naw, British heaters never work,....

I've been into Austin Minis, 'n Series Land Rovers since the late-'60s,....

 

[sogood]

So today, after a lot on comforting and hanging upside down in the bilge, I got the starter out. PITA!
IT was a replacement by the p.o. and it showed. All clean and tidy inside, no corrosion, everything shiny! Brushes were likewise fine, big and chunky with minimal wear.

It spun perfectly fine on the bench, with the bendix operating as it should. So I cleaned up all connections, checked the wiring for anything suspect (all good) and refitted it. Another PITA!

The engine seems to be turning marginally better but still no go. By the way, the engine oil is clean and up to the proper level.

I removed a plug and grounded it and got a good spark when the engine was turned on the key. So, next on the list is to look at the carb. Anything I might be missing? FWIW the battery was bought last year, kept charged and is 110 ah. According to Merc 90 ah is the recommend minimum.

Any thoughts / pointers most welcome.

 

[sogood]

Still no joy.

 

[Ericbergeron]

I have a 2007 larson lxi 208 with a 5.0 in it. It will start and run fine but when it warms up and you kill it it will not start back. Can anyone help me with this?

 

[QBhoy]

Presumably this is not a case of hydraulic locking caused by water ingress through rotten exhaust manifolds or risers ? Similar symptoms almost.

 

[sogood]

I have a 2007 larson lxi 208 with a 5.0 in it. It will start and run fine but when it warms up and you kill it it will not start back. Can anyone help me with this?

For what it's Worth, if you have an unrelated query regarding a different issue on a different engine, it's no harm to start a different thread. Having forum members answering different questions about different issues can easily lead to confusion. This is not ideal. Maybe a mod can move this to a fresh thread? Thanks and sorry I cant help.

 

[sogood]

Further to my "no start" issue. I've gone over everything that my limited abilities allow. I have 12v + at the coil but noticed that the - ground side doesn't have a solid continuity to ground, with ignition on or off. Is this right? I notice that this pale brown "ground" goes to a multi pin connector on the exhaust manifold, on a little box marked Thunderbolt IV so I'm assuming that this is an ignition control module of sorts? Inside it has a circuit board encased in a sort of clear gel material. Any thoughts or suggestions welcome.

 

[sogood]

Further to my "no start" saga, can anyone tell me what's wrong with my carb that causes petrol to soak up past the plunger on the little pump? It's quite a lot and runs down off the carb. All screws, nuts etc are fully tightened down and in the correct sequence. I changed the check ball and plunger with those from the kit I got and cleaned out all openings and passageways. Is it time for a new carb? Thanks in advance.

 

[Scott06]

Carb sounds like needle and seat not sealing, water logged float or misadjusted float level , or too much fuel pressure .

 

[sogood]

Carb sounds like needle and seat not sealing, water logged float or misadjusted float level , or too much fuel pressure .

Thanks for that. New fuel pump fitted as part of the overhaul, so I assume the pressure is ok. I've been testing with a remote tank and bulb, would this affect fuel pressure? The temporary fuel line is connected to the separator, as per the normal set up. I'm going to check the float level and operation again. Which
" needle and seat" are you referring to? Newbie here! Thanks again.

 

[Scott06]

needle and seat is inside the carburetor bowl, as fuel level raises in carb bowl float should rise up and shut off fuel flow to carb. If petrol is coming out the top of the carb this isn't working. Needle and seat can wear out or get debris that keep them from closing off flow, float can get out of adjustment or be water logged and not float(often floats are plastic covered foam), fuel pump can put out more than 5-7 psi and overcome needle and seat.

Would think you spark plugs would be black if FuEl bowl isn't over full as it would be dumping cas in the engine.

 

[Scott06]

Forgot to mention - you said the kit you got- did you rebuild the carb? All mentioned above except fuel pump would be taken care of with a good carb rebuild and setting of float level. If still happening after rebuild check the fuel pressure

 

[sogood]

Yes, carb was rebuilt, cleaned up etc. I looked at it again today, and found the float to be way off, allowing the overflow. I reset the float, using a little home made gauge, which made it a lot less fiddly, requiring 3 hands and 20 20 vision. I have neither!

Now my plunger operates without gushing fuel! I tried to start it again and was much more encouraged as it made one or two efforts. A different sound to the previous " just turning over". My battery is weak after all the trying so it's on charge for another attempt tomorrow, and I'm cautiously optimistic. Fingers crossed and thanks for the input.

 

[Maclin]

Sometimes spark plugs get wet fouled, may be time to tag team in another "crew" of spark plugs.

 

[sogood]

So, still no start. To date, I've changed plugs, leads, cleaned distributor, (rotor was new and clean) Cleaned and rebuilt carb, replaced fuel pump, cleaned all fuel lines etc. got my TDC on #1 cylinder and the rotor was aligned with the #1 position (marked) on the distributor cap. Fitted leads in correct firing order. Used a remote tank and primer with fresh fuel. Fuel is pumping into carb when throttle is activated. Have 12 volts at + side of coil.

Took starter off and bench tested same, spinning freely and fast. It was a replacement by PO and it was spotless inside. Cleaned all connections, likewise with battery and grounds. I tried to start it with shift interrupt switch connected, disconnected, shorted out, and with the coil - (tacho) connected and disconnected. I even went so far as to shift all plug leads on the distributor forward and back one position, just in case my TDC was somehow off!

​The only thing I'm finding is that the engine seems to be turning over a bit slowly. It was rebuilt by the PO so could it be a bit "tight"? I'm using a 110ah battery and have cleaned and tightened the connections in the battery selector switch. I even tried it with the battery in both 1 and 2 positions. I bring the battery back up to charge in between attempts to start and when ignition is switched on, the gauge shows 12-13 volts, as does my multi meter. Under load, with engine cranking, the voltage on the gauge drops right back to nothing.

​I did have a short ( arcing ) on the tower on the coil to the - tacho terminal, but with this disconnected it made no difference to starting. The arcing has since disappeared, possibly caused by incorrect fitting of plug leads?

​Anyway, I'm running out of ideas. I'm hoping to use a booster pack to assist in the cranking, and hopefully starting, but if anyone can think of anything I might have missed, I'm all ears! FWIW, this engine ran, very easily and very well, despite all the old corroded terminals/connections/ gummed up fuel pump and lines etc. prior to purchase and during the refurb and my various attempts, the distributor was never moved from it's original position.

Thoughts and suggestions most welcome, with thanks.