idles great on muffs -- not so much in the lake - 1992 Evinrude 90 HP VRO

Hello to all, and great forum! I have been reading/searching some before posting -- wealth of info here!


I have a 1992 Evinrude 90HP VRO. The motor will idle all day long, and not skip a beat if it is on trailer using the muffs. The motor runs super in the water at faster than idle speeds. BUT....if idling, it will stall out most of the time before you can even get it into gear when running in the water, but once it is in gear and running, I couldn't ask for a better running machine.


compression - 96 110 111 106
SeaFoam treatment -- in plug holes, and down carb throats - let sit - good smoke show
new NGK BR9HS plugs gapped at .030 - previous owner had BR9HS-10 plugs
carbs rebuilt in 2006
new thermostats in 2006
new water pump impeller 2006
still running the VRO oiler

have not done spark check -- will do this weekend
have not replaced fuel lines or primer bulb -- will do this weekend
have not replaced vacuum lines -will do this weekend

Thanks in advance for any pointers as to why it would idle perfectly on the muffs, but won't idle in the lake.


Does anyone think that just increasing the idle speed would do the trick? I don't have a tach though.

Scmutiger

Re: idles great on muffs -- not so much in the lake - 1992 Evinrude 90 HP VRO

I am hoping that installing the correct plugs will clear things up. It looks like I should actually be using the NGK BR7HS or Champion QL77JC4 plugs. Am I right in thinking that the plugs that the motor calls for are hotter than the NGK BR9HS plugs that I have it now?


Scmutiger

Re: idles great on muffs -- not so much in the lake - 1992 Evinrude 90 HP VRO

Use the Champion plugs and not the NGK's. Also, set the idle for your motor while it's in the water and in gear.

Re: idles great on muffs -- not so much in the lake - 1992 Evinrude 90 HP VRO

Thanks for the reply. I will try the Champion plugs this weekend. The freshwater landing near my house doesn't have a dock, so I may have to set the idle (in gear) while on the trailer. Will this be a problem? There are plenty of other landings nearby with docks, but they are much busier.

Thanks,
Scmutiger

Re: idles great on muffs -- not so much in the lake - 1992 Evinrude 90 HP VRO

If you have to set it on the trailer, set it around 1000-1100rpms but you'll need to fine tune it on the water.