90hp Mariner doesn’t start

[Kranjack20]

Alright if you’ve been following any of my other threads you guys can assume I’ve been having lots of problems recently. I’m new to boats don’t know much learning as I go but I have 3 different Mariner motors each with its own problem lol. So last week I bought this Glastron boat that came with a late 80s Mariner 90hp. 6 cylinder. When I went to buy it the motor fired right up idk what the seller did but I took it out yesterday and it was a pain in the ass to start but after about a minute it finally started and it ran pretty good I’d say. Pissed water good wouldn’t bog or anything. We anchored for a half hour and then when we were ready to leave the motor wouldn’t start at all so this nice guy have us a tow. Brought it back home checked spark plugs and replaced them for the hell of it. Next morning I took it back to the water to see if it would start today. Nope. It would just crank and crank and blow smoke out of the exhaust but wouldn’t start. It would start a couple times for a second then die right away. Then after I tried to start it too many times in a row on the next try it would crank for like 2 seconds and then cut out and not crank anymore. I let it sit for a few minutes and same thing. Then it would crank SUPER slowly and kept doing that so that’s when I finally called it a day and realized I wouldn’t be going on the water today. I don’t know if I fried the starter now or if the battery was dying. I haven’t tried since and it’s sitting in the garage with the trickle charger on it. At the lake I took the cover off and noticed fuel dripping from the carbs and there was a nice puddle at the bottom below the carbs. Flooded it maybe? I’ve only every worked on dirtbike and quad engines so from that experience I would GUESS this is something carb related. By the way when I bought it the guy said he did a compression test and that it was 120 on all cylinders. That seems good or no? But who knows if he was lying or not. I’ll do a compression test tomorrow if the starter didn’t get fried I was trying to start it for like almost an hour. Thanks In advance.

 

[jimmbo]

Fuel can and does spill out of the carbs any time the Engine is tilted up. Those carbs are also famous for the Floats getting stuck in the Fuel Bowl.
Even if the starter or battery is pooched, that engine is easy to pull using the Rope, as all the Plugs are out.
Have you checked that all Cylinders have a Spark that can jump a 3/8" Gap?

 

[racerone]

Pushing the key in and holding it in while cranking it over?

 

[Kranjack20]

Fuel can and does spill out of the carbs any time the Engine is tilted up. Those carbs are also famous for the Floats getting stuck in the Fuel Bowl.
Even if the starter or battery is pooched, that engine is easy to pull using the Rope, as all the Plugs are out.
Have you checked that all Cylinders have a Spark that can jump a 3/8" Gap?

What do you mean easy to start using the rope? It’s electric start it doesn’t have pull start? And what u mean a spark that can jump a 3/8 gap? I just bought new spark plugs for it but didn’t do anything gap wise to them.

 

[Kranjack20]

Pushing the key in and holding it in while cranking it over?

I did both pushing it in and out

 

[racerone]

Make sure battery , starter motor and battery cables are in good condition.----Easy to check and costs little money.-----And a review of the starting procedure is also in order.

 

[jimmbo]

I was referring to using a Rope to get the Compression Test done. And yes that engine is easy to Pull Start, as I used to do that with my 84 115, when it had a Weak Battery.

 

[Kranjack20]

Guys can someone please explain why when I try to start it sometimes it’ll stop cranking by its self and make that little whine noise? I still have the key turned but it stops cranking. It doesn’t do it everytime I’ll give it a 30 second break and it’ll crank again and then it’ll go back to cutting out.

 

[racerone]

When the motor does it's ---" want to start " ---routine the spinning flywheel kicks the bendix down.----Some will argue but.-----It is up to you to determine the following.-----Proper cranking speed to get spark that jumps a gap of 3/8" , yes or no ?----Battery in good condition and load tested ?----Cables good and connections tight ? ----Starter in good condition ??----Using the correct starting procedure ?----Post compression test numbers here for future reference.

 

[Kranjack20]

When the motor does it's ---" want to start " ---routine the spinning flywheel kicks the bendix down.----Some will argue but.-----It is up to you to determine the following.-----Proper cranking speed to get spark that jumps a gap of 3/8" , yes or no ?----Battery in good condition and load tested ?----Cables good and connections tight ? ----Starter in good condition ??----Using the correct starting procedure ?----Post compression test numbers here for future reference.

For a compression test do I take all spark plugs out and then do the test one by one for each cylinder? How long do I crank it for?

 

[racerone]

Correct.----And you crank for a few seconds till gauge stops going up.----You will likely get at 5 of 6 cylinders.---Test the spark at the same time.----And throttle dos NOT need to be open.

 

[Kranjack20]

Correct.----And you crank for a few seconds till gauge stops going up.----You will likely get at 5 of 6 cylinders.---Test the spark at the same time.----And throttle dos NOT need to be open.

All cylinders ranged from 123 to 130psi for compression while 125 was the average id say. They all got spark as well. Cables to battery look good and are tight as well as on the motor. I don’t have anything to test the battery with though. When I bought it he somehow fired it up first try. He mentioned I should probably clean the carbs. Last weekend I had it on the lake it took a minute for it to get started but once it did it ran good and idled good was just a pain in the ass to start. That same day though it wouldn’t start after we were anchored for a bit so we got towed back. I think it may be getting flooded because there’s always fuel dripping out of the carbs making a nice puddle at the bottom of the engine bay