oil in airfilter

bigoldford · Mar 23, 2011

My dad has an anniversary edition 13ft whaler with a 35 johnson. I am not sure of the exact model of the outboard but it is a 2stroke 3 cylinder with electric start. The boat is a 1998 and the motor cam with the boat so I assume it is from around the same year. I am trying to get it running again but he stopped using it when he found oil in the airfilter after on winter!

Has anyone ever heard of a problem like this before? What are some of the things that I should do first to try and fix this?

Thanks a million!

bigoldford · Mar 23, 2011

Re: oil in airfilter

Also is there any maintenance you would recommend for it since it has been sitting for 3 or 4 years now?

mark1961 · Mar 24, 2011

Re: oil in airfilter

bigoldford said:
My dad has an anniversary edition 13ft whaler with a 35 johnson. I am not sure of the exact model of the outboard but it is a 2stroke 3 cylinder with electric start. The boat is a 1998 and the motor cam with the boat so I assume it is from around the same year. I am trying to get it running again but he stopped using it when he found oil in the airfilter after on winter!

Has anyone ever heard of a problem like this before? What are some of the things that I should do first to try and fix this?

Thanks a million!

It wont have an air filter as such but an airbox/silencer. Its normal for a bit of oil to accumulate in there over time, most of it gets in as fuel/oil mix from the carb when you have the motor tilted up, the fuel evaporates leaving the oil behind. Remove the airbox and wipe out the excess if you are that concerned about it.

mark1961 · Mar 24, 2011

Re: oil in airfilter

bigoldford said:
Also is there any maintenance you would recommend for it since it has been sitting for 3 or 4 years now?

Refer to the sticky 'top secret file' thread, there is a section in there about 'awakening a sleeping outboard'.......but for starters.....

Compression test, service the carb, fuel pump, plugs, water pump, decarb engine and change the lower unit oil.

bigoldford · Mar 24, 2011

Re: oil in airfilter

mark1961 said:
It wont have an air filter as such but an airbox/silencer. Its normal for a bit of oil to accumulate in there over time, most of it gets in as fuel/oil mix from the carb when you have the motor tilted up, the fuel evaporates leaving the oil behind. Remove the airbox and wipe out the excess if you are that concerned about it.

ok in the past I have cleaned it and it will run for about 5 minutes then it is full of oil again. It is not a small amount of oil either. The motor has an oil resovior on the motor and it mixes the fuel and oil.

bigoldford · Mar 24, 2011

Re: oil in airfilter

mark1961 said:
Refer to the sticky 'top secret file' thread, there is a section in there about 'awakening a sleeping outboard'.......but for starters.....

Compression test, service the carb, fuel pump, plugs, water pump, decarb engine and change the lower unit oil.

Ok, thanks so much!

mark1961 · Mar 24, 2011

Re: oil in airfilter

bigoldford said:
ok in the past I have cleaned it and it will run for about 5 minutes then it is full of oil again. It is not a small amount of oil either. The motor has an oil resovior on the motor and it mixes the fuel and oil.

Sorry did not realise it was a auto blend, there is obviously an issue with the mixing unit then, im not familiar with those so will not try to guess what might be wrong.....

bigoldford · Mar 24, 2011

Re: oil in airfilter

Yeah sorry i should have initially mentioned that. Thanks for your help though, hopefully someone else will chime in.

Matt

smsscuba · Mar 24, 2011

Re: oil in airfilter

I have the 1998 three cylinder 35hp. I have searched this forum and also posted threads myself regarding premixing.Do yourself a favour and bypass the oil mixing valve. They are good motors but with an oil mixing flaw. Under load and high RPM they can run very lean and on the other side of the coin can also overcompensate oil. Mine was also very messy with oil residue, not any more.

boobie · Mar 24, 2011

Re: oil in airfilter

Disconnect the warning plug wiring on top of the tank, take the oil tank and mixer below it off, do some hose re-plumbing to by-pass the oil tank and mixer, mix your fuel 50:1 and you should be good to go. If you don't get rid of the oiling system you can end up with some scored pistons or worse. It was a good mtr so you should try to keep it that way.

mark1961 · Mar 24, 2011

Re: oil in airfilter

smsscuba said:
I have the 1998 three cylinder 35hp. I have searched this forum and also posted threads myself regarding premixing.Do yourself a favour and bypass the oil mixing valve. They are good motors but with an oil mixing flaw. Under load and high RPM they can run very lean and on the other side of the coin can also overcompensate oil. Mine was also very messy with oil residue, not any more.

The OEM rebuild kit for the mixing unit appears to be NLA anyway so this approach is the only solution that makes any sense, probably the best thing you will ever do for it imo......

bigoldford · Mar 25, 2011

Re: oil in airfilter

ok thanks so much everyone! I am going to try to get it off this weekend, if I am not too busy.

oil in airfilter

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