vacuum switch 225 evinrude

[josh]

Has anyone had trouble with vacuum switch that monitors restricted fuel. I seem to be having trouble with mine. When checking with vacuum gauge get different readings. It usually will trigger at 5 in. Hg. But sometimes 2-3. Seems like when fuel gets in it this has an effect on it. Should fuel get in it, I don't know if my motor is missing a piece or not. The vacuum switch is just connected to a T-fitting on the fuel line. This is a new vacuum switch, as the last one started leaking fuel. <br /><br />Any input would be greatly appreciated<br />thanks josh.

 

[josh]

Re: vacuum switch 225 evinrude

anyone?

 

[clanton]

Re: vacuum switch 225 evinrude

The vacumn switch should close at 7 in.hg.+- 1/2 for V6/V8. If it closes at 2/3/5 the switch is bad.

 

[josh]

Re: vacuum switch 225 evinrude

Thanks for the info. Do I need to replace this sensor? I had the carbs rebuilt and I asked the mechanic about it and he said to just disconnect it. The VRO is disconnected.

 

[jegervais]

Re: vacuum switch 225 evinrude

There are 5 in.Hg. vacuum switches, they're not all 7's they can be identified by color, one is grey, the other black - sorry I don't have the manual here to look up which is which. Mechanic said "just disconnect it" huh? It's there for a reason. If the fuel system develops a restriction, it can lean out the fuel supply to the motor. At hi-speeds that means a total piston melt-down. Those switches aren't a problem area, they either work or they don't. Your "mechanic" needs to go back to school (and pass this time). Exactly how are you testing the switch?<br /><br />-John

 

[jegervais]

Re: vacuum switch 225 evinrude

I was out in the garage a little while ago and happened to think of this post, so I checked out the service manual. Vacuum switch specs: black switch activates 5 to 6 in.Hg. and the gray switch activates 6-1/2 to 7-1/2 in.Hg.<br /><br />-John

 

[josh]

Re: vacuum switch 225 evinrude

hey john, thanks.<br />the original was grey.<br />the replacement was black.<br />the only number on the original is 1286.<br />the number on the replacement is <br />7.0<br />omc 438081<br />kz<br /><br />i have a second replacment. I still have the same problem. You would think i have a restriction in the fuel. I still may have. But the only thing not new is the fuel tank and vro pump. Also i tried a new fuel tank and the problem is not as bad. When i put the last new vacuum switch on i ran it and had the same problem. when i got home i took the vacuum switch off to check it and the switch was closed. I had to blow pressure in it to turn it off. After a while the vacuum switch seemed to operate ok, after the fuel seemed to dry out. Surely I couldn't have two new switches bad? Would it be ok to go to an automotive hp shop and get a vacuum gage and disconnect the original switch? <br />About to give up<br />josh

 

[jegervais]

Re: vacuum switch 225 evinrude

Josh-<br /><br />Get yourself a vacuum gauge, a 3/8" inside diameter "tee" fitting and a one foot length of 3/8" i.d. CLEAR hose. Hook the gauge up to the leg of the tee, hook one side to the primer bulb/fuel hose assembly and hook up the clear hose to the other side and then hook the clear hose to the fuel inlet on your motor. Go back the boat in at the local ramp, put it in gear and run it on the trailer (provided no-one else wants to use the ramp). See what the vac gauge reads - it must be less than 4 in.HG. at all throttle speeds. Look for a steady stream of small boubbles flowing thru the clear hose - that is bad, as it can lean out the engine and cause big-time powerhead failure. JohnnyRude V6's require 3/8' i.d. fuel supply, the fuel system from the fuel tank pick up all the way to the fuel pump must be 3/8" too. The pick up screen, anti-siphon valve, a thru hull fitting, fuel/water seperator, even the primer bulb can be the cause for a fuel restriction. You've got to make sure there is no restriction. And if vac gauge reads too hi, you've then got to find the problem. Sounds like your engine needs a 7in.Hg. switch, those switched are not normally problematic. It is possible an excessive vacuum damaged it.<br /><br />-John

 

[josh]

Re: vacuum switch 225 evinrude

ok, I will try this. I already have a vac gauge but will need the t fitting and clear hose. I will let you know the results. Thanks for the advice.

 

[josh]

Re: vacuum switch 225 evinrude

ok, I will try this. I already have a vac gauge but will need the t fitting and clear hose. I will let you know the results. Thanks for the advice.

 

[josh]

Re: vacuum switch 225 evinrude

Ok, finally had time to take the boat out and check it. The alarm would go off but the vacuum gage never read above 4in.Hg. Since i was suspecting fuel getting in the sensor, I decided to let the the vacuum switch dry out, put a 18in. piece of vacuum line instead of the 4 in. piece that connected the vacuum switch to the T-fitting. Ran for a good while(about an hour) at different speeds, and the alarm never sounded. As far as bubbles, very few. Is it ok to leave it like this? I wouldn't think this would make much difference. Any advice would be greatly appreciated.<br /><br />Thanks, <br />Josh

 

[jegervais]

Re: vacuum switch 225 evinrude

Josh,<br /><br />I would not recommend leaving the clear hose in place very long. Its not rated for marine fuel applications its only for testing purposes.<br /><br />-John

 

[josh]

Re: vacuum switch 225 evinrude

I planned on replacing the clear line with fuel line. Do you think it would be ok to leave 18in. of fuel line from t-fitting to vacuum switch? (the Existing t-fitting not the test one)

 

[josh]

Re: vacuum switch 225 evinrude

When I say the 18in. of fuel line I talking about instead of the 4in. piece. I believe that having this hose longer kept gas from getting in the sensor. Is is safe to leave a longer hose here?<br /><br />thanks josh

 

[jegervais]

Re: vacuum switch 225 evinrude

As long as its a piece of marine-rated fuel hose you should be OK. I recommend against using automotive hose in any marine application, it doesn't have the USCG fire resistance or permeation ratings you require (i.e. type A1).<br /><br />-John

 

[jegervais]

Re: vacuum switch 225 evinrude