Pulse Limiter

[Mofuk]

I have an "88" Rude 225 with VRO issues, I believe I have narrowed it down to the pressure/vacuum coming from the pulse limiter being insufficient to operate the pump. I have to prime the bulb in order to keep it running, Not a pleasant way to go fishing...LOL

1. black limiter in now, and is it really necessary to switch to blue and why?
2. what readings should I get out of the pulse limiter in order to operate the VRO pump.
3. just in case If reading is "0" what do I do next?

4.Can I go with premixed gas and use an electric pump, capping off pulse limiter so I don't have to worry about a pulse limiter going bad again?

 

[petryshyn]

Re: Pulse Limiter

I doubt the pulse limiter is causing the problem. More than likely a tired VRO. The blue limiter is a change up which is typically supplied with a replacement VRO. Just to be sure, remove the pulse line from the pump and try blowing and sucking by mouth....it should allow flow in both directions (engine side)

 

[Mofuk]

Re: Pulse Limiter

I took off the black limiter and it does allow air to pass both way identical to the blue.

VRO is new.

 

[Mofuk]

Re: Pulse Limiter

How much pressure/vacuum should be coming from the limiter?

 

[boobie]

Re: Pulse Limiter

First off an electric fuel pump is a big no-no. That has been discussed on here many times. My question would be, what's the compression on # 6 cyl compaired to what the rest of them are ? It's also possible to have a bad new OMS pump. It's happened before.

 

[ezeke]

Re: Pulse Limiter

The pulse limiter is a check valve that protects the fuel pump diaphram by closing in the event of a backfire. It is open in both directions during normal operation.

The black ones were replaced by the blue and gold ones because the black ones failed to protect the fuel pumps as well.

Some V8 outboard motors used electric primer pumps. The problem with an electric fuel pump is that you need to have a regulator to turn them off when/if the engine stalls. The OMS, VRO and conventional lift pumps used on most OMC outboards did not need regulators because if the engine stalled the pumps simply stopped pumping.

 

[boobie]

Re: Pulse Limiter

The electric fuel pumps used on a V-8 were a primer pump only and run by a toggle switch , then when released it would shut off. It was mainly an electric primer bulb and did not constantly run. The V-8's had two VRO's on them and once you got it started there was plently of fuel.

 

[Mofuk]

Re: Pulse Limiter

Looking at it from the back exhaust side!

All spark plugs removed
PSI
Left Right
1. 75-80 2. 75-80
3. 55-60 4. 75-80
5. 75-80 6. 75-80

Cyl #3 ? much lower than the others.

Book says to do a compression test with wide open throttle. Will retest if WOT is needed.