Gunky stuff on left side

[Guest Ken8143]

I thought I was leaking some oil from the valve cover but don't think that is a big issue - but there is all sort of junk on the left side, especially in front of the front carb, extending down over the carb drain hoses, down the left side - and it looks moist above the carb where the book goes to the air box.

 

any idea what is happening here and what it would take to fix it?

 

87 VR, 67Kmiles, run at about 44 mpg on trips, maybe 40 around the house. runs smooth, starts well

[Neil86]

The crankcase vent hose on a 1st gen ties into the bottom of the airbox so the fumes can be drawn into intake and burnt.

There is also a drain hose to drain accumulated oil back to the crankcase that tees into the vent hose going to the airbox.(85 and newer).

A few things to check.....

The crankcase vent tends to carry more oil into airbox if the oil level runs above the 1/2 way mark on the oil window (on main stand engine warm and off a few minutes).

Remove air box lid and inspect for abnormal amounts of oil sitting in the airbox. Possibilities are plugged/kinked drain hose. See if you can see that the crankcase vent hose is properly connected to the bottom of the airbox. Its not too unusual to see some oil residue on the left carbs as the oil runs to that side when the bike is on the sidestand and the drain is in one corner of the airbox. Sometimes removing the boots from the airbox, thoroughly cleaning and resealing with RTV sealant helps.