Rpm issue?

[Craig]

Changed the plugs app 1 month ago and to be honest we hadn't had the opportunity to go out on the boat since. We've been out the last couple days and I notice that I'm showing app 7k on the tach sand only getting 41 mph? Last time we were out with the same number of people and a full tank of gas I remember getting up to 47'ish mph. I replaced the plugs by oem specs/parts #. I also checked the air filters at that time and saw no issue. I know everybody also recommends checking your plugs first on these motors (1.8). I'm tempted to put the old plugs back in and see if there is any change since I kept them for spares. Thoughts or advice is welcome..

 

[jdonalds]

I think putting the old plugs back in is what I would do. Did you gap the new plugs? If they are per the boat specs I guess they are standard plugs not iridium. I only ask because if they are iridiums they can be trashed by the action of gapping, or even checking the gap.

 

[Craig]

Standard NGK's and gapped to spec. To be honest the first day out we had 9-10 people in the boat so I didn't expect it to run as normal. But when we only had 4 people in the boat and a half tank of gas at the end of the second day I was a little shocked.

 

[PEARCE]

Check to make sure you connected each wire to its proper distributor. I left one wire disconnected after changing the plugs and I didn't have full RPM and a very rough idle.

 

[itsdgm]

Are you boating on the same lake? Or do you happen to be at a different lake at higher altitude?

 

[Craig]

Found the issue and to be honest I'm ashamed to tell you what happened. Apparently when changing/replacing the oil, the engine block is not level while on the trailer, even when you put a level on top of it. While changing the spark plugs back to the old set today to see if that fixed the problem, I decided to check the air filters again. When I disconnected the air filter housing I noted oil on the bottom of both (not a tremendous amount but you could definitely feel it on the surface of the plastic housing. I took them apart and sure enough the bottom fourth of the filters had oil soaked into the filter. I cleaned up the oil and took the boat back to the water. We launched and checked the oil level while floating, ended up extracting app 1/2 qt from each motor. We then went for a quick run. Rpm's at app 7200 and 48/49 mph. I'll be ordering new air filters when we get back at the end of the week.

Anybody see any issue of running for a couple days without an air filter? If no then our boating is over for the remainder of the vacation.

 

[Scottintexas]

it shouldn't be an issue as long as you are careful with it, I think I have seen posts of a couple of members running without them,

 

[itsdgm]

Glad that you figured it out. At least it's a simple fix!!! I'd run mine without the filters for a few days to save a trip. My filters don't seem to ever see any dirt/debris anyway. I'd think that you should be fine.

 

[jdonalds]

I don't think I'd have a problem running without the filters. What could possibly get sucked into the engine that the filters need to trap?

Perhaps someone can add some information here that would make me change my mind.

 

[Boat Crazy]

Glad you found your problem and are back up and running. The next time you change your oil just place the level on top of the engine. It helps to have someone outside of the boat to crank on trailer jack while someone monitors the level, otherwise you will be making lots of trips in and out of the boat.