fuel in the engine oil ???

[ecsloth]

Hi all
When draining the engine oil on my GS 850G 1981 , I notised that the amount of oil drained was more than 6 litres and mixed with petrol . ( and VERY thin)
and wondered how this could happen ?

I suspect that it could be a faulty fuel petcock , allowing fuel to get into the engine through the carbs when not in use ?

Any thoughts ?

[Rich82GS750TZ]

Firstly, welcome to the forum.

You have a common problem. You likely have one of all or these issues:
1) You left your petcock on PRIME, allowing fuel to flow into the carbs when the engine not running. in the ON or RES positions, when operating correctly, the vacuum petcock only draws fuel when the engine is running.

2) At least one of the 4 needles/seats that would stop fuel flow when the carb bowl float rises enough to seat the needle is not doing their job. In theory, these should stop the fuel flow even if you leave the petcock on PRIME. In practice, they were never really up to the task.

3) Petcock is faulty and lets fuel flow when in ON or RES position.


TL/DR - It's a (over)fueling problem. The fuel is overfilling in the cabs and running into the engine.

[rphillips]

Like him, first is Welcome, 2nd is just what he said. Most here have Been There Done That... Search feature will have recommendations for fix'in it, then you'll have to decide what route to take. Good luck..