Motor Maintance Sparkplugs and Water Pumps

[Captain PartyMarty]

A few questions for you Mercury guy's

I have a 2005 135hp Optimax and have two questions

1) I am replacing the Sparkplugs, this season, as I don't know there history and the last owner through it would be cool to put Automotive ones in. I bought the recommend Spark plugs for my engine NGK IZFR5G. Here is where it get confusing, My maintance book lists the sparkplug gap in at the begining of the book and again on the pages where it shows you how to replace them. The problem is one says the gap should be 0.0031" and the other says .0040". Any body know what is correct?

2) I am also replacing the impeller. My maintance book lists that I need Loctite 5900 RTV sealant which is to be placed on the flange surface. (It doesn't show what the flange surface is) My question is the Loctite stuff is very expensive at around 80 bucks for a large tube. Do I need to buy this or will any RTV silicon sealant work Lordco and Canadian tire have Ultra black RTV Gasket Sealer? Also what does the book mean by flange, the videos I have seen online put the sealant on a line towards the back of the pump which separates the exhaust from the water is this the correct way to do this? Also My book says I should put Loctite 271 on the gaskets, seems this would make it very hard to remove them later on, whats you opinion use it or leave them dry?

Thanks for any help

Capt

 

[Bait&Sea]

I too have a 135 Opti and this is my take on it, manufacturers through the years of a particular engine family will change parts based on various factors (ie: cost, availability,corrective action ect...) With regards to the different plug gaps for our motors the early year Optimax motors were originally assembled with platinum plugs PZFR5F-11 with a gap of .043 then a few years later they switched over to an iridium plug IZFR5G with a gap of .031 Is it possible you have the PZF plugs in there now? I have yet to be able to get a solid reason for the switch but I can tell you that I still have the PZF plugs in mine gapped to .040 with hundreds of hours on them and no issues whatsoever. In your case I would gap the plugs you purchased to the .031 spec and pay close attention to your motors performance / sound / temp ect for the first little bit simply as a precaution. Oh ya, double check those printed specs in your manual as 0.0040 may be a bit tight

 

[Captain PartyMarty]

Thanks for the info, I added an extra zero...

 

[JAC]

I had a opti a few years back and there were 2 plugs that were tough to get at. I used a small hose and stuck the plug into the hose and then started it in the hole. This way you will not strip the threads. I never use sealant when I put in impellers.

 

[Captain PartyMarty]

I have two plugs I can't get out at the moment. Need to find the correct extension!

 

[JAC]

Yep you need 2 swivels joints and 1 or 2 extensions. When you replace the plugs use a hose so that you don't strip the threads. Just push the plug into the hose

 

[Bait&Sea]

Cant remember for sure but how about a 5/8 plug socket and an open end wrench?

 

[coopsie]

I had a 2004 opti 150 and I just took the cowling off the bottom not that hard. And for rtv sealent the merc guys put it on the back part of the leg where it meets the upper leg.

 

[Cuba Libre]

While we have some knowledgeable boat mechs on this site.. I have found that Boat Doc on iFish really can help as he knows Yammies and Mercs inside and out. Just sign up to the site and give it a try-- but be warned.... Ifish is totally ANAL if you try to post a link that might conflict with one of their sponsors http://ifish.net/board/showthread.php?t=3731&page=77

BTW-- he is a senior mechanic with Stevens Marine just outside of Portland

 

[AquaDisiacIII]

the bottom port plug is the worst. Disconnecting the ignition coil plug and using a universal 5/8 plug socket with an extension will help. The hose trick is the only way to reinstall the plugs or else its a pricey thread repair. Using a gasket sealing compound like quicksilver perfect seal lightly on the water pump gaskets will work as well.

 

[Captain PartyMarty]

Thanks for all the input guy's!

I removed all the sparkplugs and was surprised to find Autolite plugs. I guess the previous owner was a bit of a cheapskate, the plugs where in very poor shape. Also all the plugs where gaped wrong. Reinstalled new plugs and wires and now it purrs like a kitten at idle and it start with almost no cranking.

Also did the water pump was no issue at all pretty simple job!

Capt