MerCruiser 350 Hard to start after running

I was on the water for about an hour yesterday, pulled into a cove for some swimming & killed my engine. When I tried to fire it back up (about 1 hr later), it wouldn't turn over at first. I thought it was my batteries or starter ... checked the voltages, and they seemed normal (I charged them the night before). I took the plug out of cylinder number 5, and it was clean.

I should first say that I just installed this engine, and this was my 2nd time out with it. The previous engine was a V6, so is the additional weight of the 350 bringing the transom down enough to let water up the Y-Pipe?

After a couple of cranks, the engine started to turn over, but VERY slowly. A short blast of starting fluid made it turn over a little quicker, and it eventually started back up. But it sounded much different, quiet but rough, almost like it was running on only 4 or 6 cylinders. About a minute later and it began to run smoothly, and sound normal. My best guess is that I need riser extensions ... and I got some water pushed up through the exhaust.

The motor is a 1997 350, Vortec heads, SEI 116 (Alpha 1 Clone) Outdrive. Block is a Chevy L31 Long Block. Edelbrock 1409 Carb w/ Elec Choke, Edelbrock Performer RPM intake, Carter Elec fuel pump.

Thank for any help!

Re: MerCruiser 350 Hard to start after running

I'm going to start by draining the oil & checking for water. Also, the next time I'm on the water, I'll measure how high the riser sits above the waterline.

If anyone can think of anything else to check/test, let me know :joyous:

Re: MerCruiser 350 Hard to start after running

LiquidC said:

I'm going to start by draining the oil & checking for water. Also, the next time I'm on the water, I'll measure how high the riser sits above the waterline.

If anyone can think of anything else to check/test, let me know :joyous:

Click to expand...

Ayuh,.... If it happens Again,.... Take ALL of the spark plugs out, 'n turn it over to expel the water,...

You'll be Lucky, if ya haven't already done internal motor damage to yer Brand new motor,......

Ya need a Minimum of 13" from the tippin' point of the risers, to the waterline outside the hull,....

Re: MerCruiser 350 Hard to start after running

Thanks Bond-o. I'm Irish, so I hope I'm lucky this time.

What's the best way to measure the distance from the waterline to the top of the risers? The riser height seems fine with the boat unoccupied, but load up a few fat guys & it brings it down quite a bit. Do I do the measurement with the boat loaded?

Thanks

Re: MerCruiser 350 Hard to start after running

LiquidC said:

Thanks Bond-o. I'm Irish, so I hope I'm lucky this time.

What's the best way to measure the distance from the waterline to the top of the risers? The riser height seems fine with the boat unoccupied, but load up a few fat guys & it brings it down quite a bit. Do I do the measurement with the boat loaded?

Thanks

Click to expand...

Ayuh,... Build a Sight Level, with a length of clear tubin',....

If ya don't know how it works,.... Google it,....