Proper spark plug and gap for 87 Johnson 90HP VRO

[jokeman88]

Getting conflicting info from manuals and stores. After reading some posts here, i've read to only get Champions. What's the proper gap and model?Thanks,

[DHPMARINE]

Joke, I don't have a reference here at home,but if you took out Champ QL77JC4 's use the same,gapped at .030".DHPThere is another site that has a plug chart for OMC motors.Boatsetup.com,as I recall.

[flech01]

I think this is what you are looking for. web page

[flech01]

Sorry this is what you are looking for. web page

[rickdb1boat]

QL77JC4 are the plug you want gapped at .030, unless you do alot of slow running, then I would open up the gap to .040...

[walleyehed]

QL82C is the newest recommended plug for that application, and Ricks got the proper gapping listed.

[jokeman88]

I have the QL77JC4's gapped at .30. This should be okay?

[walleyehed]

They will be absolutely fine...as Rick said, if you have some rough Idleing issues, try gapping at .035-.040.

[seahorse5]

The official factory recommendation is to use the QL82C gapped at .030" for best results, especially at lower speeds. You can also use the QL77JC4 which was the original plug, but was changed back in about 1996.

[rickdb1boat]

SeahorseCan you list some of the engines that were changed over to the QL82C plug? Has me curious what should use what, as the QL77JC4 was the mainstay for years. I know that after about 1992, they did switch over to the QL82C plugs for the most part. Thanks,

[seahorse5]

Rick-boat,Just look in the annual Parts and Accessories book, that has the only official factory plug recommendations. A lot of the 9.9 and a few other small motors changed to the 82C's also. It was the same time the 60 degree engines came with QL78YC instead of the QL77JC4. This also happened shortly after Champion Spark Plugs got bought out and the new owners revamped a lot of things.

[melbournegreg]

Does the update to the QL82C also apply to the 70HP VRO (1988)? I only see the QL77JC4 listed on the champion website (www.championsparkplugs.com)

[seahorse5]

Greg,Your 70hp takes the QL77JC4 plugs gapped at .030". The 1994 and later 70's take the QL78YC sparkplugs.