Breather Cap

[Kasia]

I noticed plenty of venting from the breather cap. I have installed the Indigo crancase breather to the carb in order to reduce engine fumes. It seems that the breather cap is also a fume problem. Any ideas anyone?

Chris
A30 383

[Don Moyer]

Chris,

The Indigo crankcase ventilation kit creates a low pressure within the crankcase which should remove blow-by (combustion gasses leaking past the pistons) and prevent it from escaping from any location, including the breather cap of the oil fill tube. The kit is quite effective, and if you still have blow-by from any location on the engine after installing the kit I recommend the following action:

1) Retime the engine by loosening the distributor hold down bracket and rotating the distributor a small amount in each direction to see if you can get a slight increase in RPM. If you can get the RPM to increase, lock the distributor in that location.

2) Check the compression. If compression is unusually low in one or more cylinders, try a Marvel Mystery Oil (MMO) treatment (5 or 6 squirts of MMO in the spark plug holes of the low cylinders) in an effort to improve compression.

3) Tune up the ignition system if you have not done so lately.

4) If everything else is in good condition and you still experience a lot of blow-by, you may have to consider that there is a restriction within the exhaust system. This is a very difficult problem to troubleshoot and will usually require installing a low pressure gauge between the back of the manifold and the rest of the exhaust system. It is sometimes easier to simply remove the hot section and check it for a buildup of crud, usually where the water enters the system.

Don

[Kasia]

BreatherCap

Don, thanks. I will perform the trouble-shooting you suggested and post the results.

Chris