01 175hp EFI

[RuneRanger]

Hi Guys - Just purchased my first ever bass boat last weekend (yay).

Some things to note:
- 01 19ft Ranger 461 VS w/ 175 hp EFI
- The merc on it starts first turn
- Appears to idle rather low (almost sounds barely on, sometimes dies out)
- A couple cylinders blew, motor had been rebuilt a few years ago (50-75 hrs on new motor according to seller)
- Sort of slow getting on plane, but when it gets there rides nicely and tops out around 50mph
- Pretty scuffed prop
- prev owner hasnt changed spark plugs this year and has 6mo old gas in the tank.

I am not mechanical at all - could you help determine why the engine is running rather poorly? or have any tips to help this first time buyer?

I am going to burn through the old gas & put new gas, new spark plugs, new prop... then I am hoping it should run great.

EDIT- sorry If this post doesn't belong. I am new around here - my brother referred me as a longtime bass boater himself

[EuropeanAM]

Perfectly fine here. If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

Start with the BASICS: Compression Test, Spark Test, and Fuel Quality/Delivery Tests.

[RuneRanger]

Thank you @europeanAM

update - compression test seemed ok. I believe all 6 were running around 110, within 10 apart.
- popped the plugs out and one of them didnt have a 'gap' at the end, that could have been the issue my buddy said.
- installing new spark plugs today and a new water separator over the weekend

[JOE54]

may also need scan of all sensors and switches to verify they are operating properly

[TKress]

Make sure to buy a Mercury OEM manual (not aftermarket) if you are going to do any work on it. It will lay everything out step by step and gives torque values for most everything needed like spark plugs and prop. You can order one from Don at European Marine in the previous post or most other reputable dealers. It will be worth every penny you pay for it.

[EuropeanAM]

Thank you @europeanAM

update - compression test seemed ok. I believe all 6 were running around 110, within 10 apart.
- popped the plugs out and one of them didnt have a 'gap' at the end, that could have been the issue my buddy said.
- installing new spark plugs today and a new water separator over the weekend

Make sure you inspect that cylinder where the gap was closed. Most of the time it's due to damage or debris in the cylinder- if there's any aluminum color to that plug, you'll need to find out why. Even if all is "well"- make a note of exactly WHICH cylinder that plug was in.

[JOE54]

^^^^^+1

[RuneRanger]

Thanks for the shouts guys , not sure which cylinder had the bad one, I'll try to check again - with new plugs its definitely running better.
Noticed Some clanking sounds going on in the lower unit too.
I should have brought a pro with me to look at this thing.

[leonreno]

Thanks for the shouts guys , not sure which cylinder had the bad one, I'll try to check again - with new plugs its definitely running better.
Noticed Some clanking sounds going on in the lower unit too.
I should have brought a pro with me to look at this thing.

depending on the nature of the clanking sound check out this thread.
https://www.bbcboards.net/showthread.php?t=1237177