Merc V6 oil injectionIt just doesnt seem right

Have just rebuilt a 135hp Mer

Have just rebuilt a 135hp Merc and in cleaning out the oil lines it just didnt seem right. From the outlet of the oil pump there is a hose that goes to a tee fitting where i assume this is where the oil is mixed. When i blow through the fuel side of this fitting everything seems ok. When I blow through the oil side in the correct direction it seems blocked..cant get any flow. I automatically assumed this fitting was stuffed so ive got another 3 of these second hand and they all seem to be the same. Could this be possible.
Is there an explanation to this??
Any help would be appreciated..

Hi. the other end of this cle

Hi. the other end of this clear oil hose goes into a one way valve that's attached to the "y" shaped fuel hose. This valve requires some pressure higher that one can normally blow by mouth which explains why it seems to be blocked. There's an oil output test that you can do to check if oil pump is working properly. Let me know if you need the details.
james

James thanks for the quick re

James thanks for the quick reply
The details for the oil output test would be great.
What concerns me most though is that i am blowing through this valve with compresser air at about 100psi and still no flow.I realise 100psi isnt a great deal of pressure when we are talking about oil but does such an oil pump create this much pressure?? And if it does is this load on the oil pump putting too much strain on the plastic grear on the crank?? This gear failed which is why the motor was re done in the first place.
Would I be best off disconnecting the remote oil tank temporarily and checking that the engine is using the oil out of the onboard tank while on a 50:1premix?

" Hi. It's highly unlikely

" Hi. It's highly unlikely that all 4 valves are defective. Observe correct valve direction flow during testing. This brass one-way valve requires only about 2-3 psi pressure to open when blowing from the smaller diameter end (input) and about 6 inches of mercury when using a vacuum pump at the bigger end (output). Subjecting this valve to 100psi air pressure may damage it.

In Mercury V6's, the oil pump's plastic drive-gear is prone to damage when engine is started-up after a long storage especially if storage oil was not applied. Since this plastic gear and its steel driven-gear partner is situated in the upper part of the crankshaft (cyl #2), gravity will force whatever any fuel/oil mixture has coated said gears to drip down. Unavoidably, after a long standby, both gears will eventually be dry.

Imagine what happens when suddenly these two poorly or unlubricated gears spin during the initial start-up. Obviously friction heat will damage the plastic gear resulting in oil pump failure. Therefore always use the recommended storage oil...
Here's how to do an oil pump volume (flow) test:
1. Run engine off a remote fuel tank with 50:1 premix. Be sure engine has proper cooling water.
2. Disconnect the clear output hose off the brass valve of the Tee fitting and direct hose to a graduated container.

3. Flow Specs for 135 thru 175 models are as follows:

A)1500RPM with oil pump link arm ATTACHED
= 6.8cc +/-10% in 3 minutes

B) 1500RPM with link are DISCONNECTED
= 17cc +/- 10% in 3 minutes

With your recent experence of engine damage due to oil pump failure, you may want to condemn the oil injection system and just premix 50:1 at the tank. This way you minimize the risk of oil-related engine trouble.
Good luck, james "

James
Thanks for the info I

James
Thanks for the info I have removed the fuel lines off that fitting and used a straight hose to supply pre mixed fuel. Started the engine and did the flow check as you said but with the brass fitting still attached. The results were within range of your specs. I think the problem did arise from the motor sitting for a couple of years. Now back to this valve my assumpions now are that by blowing thru this fitting by mouth wasnt enough pressure to open it yet when i applied compressed air to it the pressure may have been too high causing the valve to somehow shut again. That aside my problem is sorted had the boat out today and it went great. Again thanks for your help in sorting this problem out.
Tony

" Tony,
Forgot to mention th

" Tony,
Forgot to mention that the valve can be tested by sucking at its big end as opposed to blowing from its small end. Remember to first clean valve before do so. However same valve should not allow air to flow when air is blown from its big end. This is to prevent fuel from entering into the oil output hose. Glad to be of help. james "