8 HP Mariner issues

[Bullie]

I am working on an 8 HP Mariner od107882 and I am stumped. I checked compression at 102/105 and spark easily jumps 1/2 inch or more. I just can't get it to even act like it wants to start. I have squirted a little gas in the carb throat. Barely a pop or nothing at all. I removed the spark plugs and put a little fuel in the cylinders. Nothing.

The PO said it was running a year so so ago...but we have all heard that before. What should I try?

 

[flyingscott]

Have you checked the flywheel key? Are the plugs wires on the correct cylinder? Are the spark plugs wet with fuel?

 

[Bullie]

I didn't have the right size bolts to pull the flywheel so I couldn't check the key. I was planning on picking some up tomorrow to check things out under there. The plug wires look to be on the correct plugs, their length would make it impossible to switch I think. The plugs do get wet, yes. I thought the timing might be off. Hopefully it will be something that simple.

 

[flyingscott]

What is your cold starting procedure step by.step?

 

[racerone]

When did it run OK for you ?-----Another new purchase perhaps ?-----The wires FROM the switch box could be going to the wrong coil.-----For you to check out.

 

[Bullie]

What is your cold starting procedure step by.step?

With this motor I pumped the bulb tight then depressed the primer 2x. Then pulled it over. I just bought this motor and feel like it will need a carb cleaning at least. When it didn't hit at all I squirted some fuel mix down the carb throat and tried again. Then a little fuel into the cylinders. Then I rechecked myself on compression #s and spark because I felt it should have at least made a little smoke for me.

 

[Bullie]

When did it run OK for you ?-----Another new purchase perhaps ?-----The wires FROM the switch box could be going to the wrong coil.-----For you to check out.

racerone, it is a new purchase. I have never seen it run. I just got the usual, "It ran last year." from the previous owner. I will check the leads from the switch box. Thanks for the insight.

 

[Mohawkmtrs]

Have you checked for spark with an open air adjustable spark tester?

Had a Merc 4hp four stroke in...wouldn't fire but had spark...installed new plugs and BINGO!

 

[Bullie]

The flywheel key is in very good shape. Nothing jumped out at me as wrong under the flywheel. I also switched the leads from the switch box to the coils and spun the motor over. Still not even a cough.

 

[Bullie]

Have you checked for spark with an open air adjustable spark tester?

Had a Merc 4hp four stroke in...wouldn't fire but had spark...installed new plugs and BINGO!

Yes. At this point I have checked it several times. Spark will jump 1/2 or more. Bright blue lightning.

 

[Bullie]

I don't think the plugs are correct for the motor. But, they are sparking too.

 

[flyingscott]

If you have the round knob for the primer turn it all the way to the right after priming then try starting it. This will give you a high idle for starting. If you have the square knob pull it out all the way out.

 

[Bullie]

If you have the round knob for the primer turn it all the way to the right after priming then try starting it. This will give you a high idle for starting. If you have the square knob pull it out all the way out.

It has the round knob. I will give it a shot. I cannot figure out why it won't pop for me.

It loses prime on the hose really fast. I am not familiar with this carb at all. But, it is spitting gas from the hole on the side of the primer and from under the flat plate on top so I feel like several gaskets are probably bad which would account for the bulb going soft so fast.

 

[harringtondav]

My '82 Merc 4hp 2 cyl "Gnat" is rarely used, and is stubborn to start. I dug deep and found the reed valves became stuck after long periods of idle from the gas/oil residue glue. When I give it a shot of ether starting fluid it takes off. I don't know if the ether dissolves the goo, or helps touch it off, or both. But it works. Once it starts the fresh fuel finishes the clean out, and it runs fine.

 

[flyingscott]

DO NOT use starting fluid on a 2 cycle. Rebuild your carb because the primer is probably flooding the motor. Get the kit that has the fuel pump and primer gaskets in it. It is a pretty common thing to happen to those carbs. Make.sure you remove the brass screw under the primer and service the ball and spring.

 

[Bullie]

DO NOT use starting fluid on a 2 cycle. Rebuild your carb because the primer is probably flooding the motor. Get the kit that has the fuel pump and primer gaskets in it. It is a pretty common thing to happen to those carbs. Make.sure you remove the brass screw under the primer and service the ball and spring.

Ok. I will pull the carb today, check it out, and order the kit.

 

[harringtondav]

DO NOT use starting fluid on a 2 cycle.

I don't give advice unless I've successfully done it myself. My motor above and my Toro 2 stroke snowblower have had no problems. Ether will wash off cylinder lubrication, if used excessively. I use a single shot through the carb before starting. It scavenges through the crankcase with the gas/oil mix and burns off with the first spark pop. Trying to keep the motor running with ether is asking for trouble.

 

[flyingscott]

I don't give advice unless I've successfully done it myself. My motor above and my Toro 2 stroke snowblower have had no problems. Ether will wash off cylinder lubrication, if used excessively. I use a single shot through the carb before starting. It scavenges through the crankcase with the gas/oil mix and burns off with the first spark pop. Trying to keep the motor running with ether is asking for trouble.

Maybe you should spend some time trying to figure out why you have 2 bad starting 2 strks. Instead of using a bad shortcut to get them started.

 

[Bullie]

Ok. I installed the Mercury/Quicksilver carb kit. The diaphragms were all stiff and cracked so I was very optimistic after the carb rebuild I am still not getting it to start or sound like it wants to. Any suggestions?

 

[hardwater fisherman]

Did you check the spring and ball in the bottom of the primer "bowl" as flyingscott suggested? I also have a merc carb that was leaking fuel from the hole in the primer and I found I had to pull the primer at least 6 times and leave it open... Not like the 2 times and shut like written in the manual.;..