mercruiser spark plugs

[LazyCruiser]

Hello everyone
I won't be bothering you'all in this forum much as I surely am not a gear head

But do want to try one thing on my '95 Bayliner 2452 Classic Cruiser and that is to change the spark plugs (it starts kinda rough, and this is all that I'd be comfy trying to do) It is a 5.0, alpha 1 drive and 190HP.

I stuck my head in there and did not even see the plugs?
Where are they and how difficult is it to change them?

thanks very kindly and don't you guys make fun of me

 

[Alumarine]

Re: mercruiser spark plugs

Hello.

If you find the distributor which is at the back of the engine you can follow the spark plug wires to the spark plugs.

They will be under the exhaust manifolds.

Depending on your engine bay you may not be able to see the spark plugs.
You'll have to do it by feel.

Good luck.

 

[Utahboatnut]

Re: mercruiser spark plugs

Depending on how the engine cover/doghouse is set up you may have to dismantle or remove some things to get even decent access to the plugs. Does it have a sunlounge over the whole rear of the boat or a doghouse and jumpseats on either side. Mine has a doghouse and jumpseats but I have to lift the whole doghouse out of the boat in order to have enough access to get to the plugs. If its a sunlounge type you might get lucky and have enough room on either side but you will probably have to put a blanket or something down in there to lay on and may have to stand on your head for a few of them. The plugs should be AC MR43T unless it is a vortec. But if you can get one out just take it with you and have that one matched. Your choice but I got suckered into the fancy Iridium plugs that are at least double(or more) in price and I saw NO performance, ease of starting, or any other improvement which would warrant the purchase of the pricey stuff. The standard plug is what it came new with and what it was designed to run with. Following the plug wires from the distributer is a good idea for a starting point. Remember to just do one at a time, remove wire, replace plug, replace wire, move to next one no chance for a mix up(it happens to even the pros from time to time) The front plugs on either side can be tricky to get to because the exaust manifolds drop down right there. A ujoint on an extension can help or try getting the plug threaded as far in as possible then insert plug socket onto plug then put ratchet with extension onto the socket and remove in the reverse. Also remember there is a squash washer on the new plugs so it contacts the block and then needs to go another 1/2 to 3/4 turn to be tight. Good luck you can do it....

 

[fossill]

Re: mercruiser spark plugs

Save your money on the irridiums. They are designed to last the length of the emmissions warranty on new cars and trucks, 160,000km or more depending on model, saving the manufacturer of having to replace them on their dime. They offer no performance gains.

 

[LazyCruiser]

Re: mercruiser spark plugs

Thanks, sounds like a CHORE and some skinned knuckles.

I appreciate everyone's help!

-smiles-
Sarah

 

[Aloysius]

Re: mercruiser spark plugs

Don't yank on the plug wires to remove them..they're fragile. Use a tool that pulls on the boot only.

Don't expect miracles..plugs don't cure everything.