94 evinrude 200 bypass blew off

[sgcheek]

My 94 200 blew the port side bypass hose fitting on the thermostat housing. I did not know this until after I limped home today and checked it in the driveway. The engine was running very poorly, with a lot of gas dripping out of the exhaust when I pulled it onto the trailer at the ramp. No overheat buzzer ever sounded. My plugs were very wet. Does anyone think I could have damaged anything? I'm hoping that just too much water was pumping through, causing the engine to stay too cold, fouling the plugs. How can I check to see if my overheat warning is operating normally? I get only a 1/2 second beep when I turn the key on to start the engine.

 

[OBJ]

Re: 94 evinrude 200 bypass blew off

Hi sg....the circuit is pretty easy to check. On each head is a temp sensor/switch. When the sensor heats to a predetermined temp., is closes causing the circuit to go to ground and sounding the horn.<br /><br />Look for a tanish wire from each head connected to an Amphenol connector (rubber enclosed connector). Pull either one apart and with a jumper, put the end that goes to the wire harness to a good ground. Turn the key just to "ON". The warning horn should give a steady tone. Do this for the other head.<br /><br />This will check out the circuit to the horn. But it will not check the temp sensors. It's really not a probable thing that both temp sensors would go bad at the same time. To check the sensors requires pulling the head and removing the sensors.<br /><br />You are probably right that the engine overcooled a little plus the water running over the spark plugs was grounding them out causing the poor running conditions.<br /><br />Keep us posted to any more problems.

 

[seahorse5]

Re: 94 evinrude 200 bypass blew off

You may have a plugged up or sticking pressure relief valve or what is commomly called a "blow off" valve. Replace the plastic valve with one from a '97 or later parts catalog to make sure it has the air bleed grooves in it.

 

[rodbolt]

Re: 94 evinrude 200 bypass blew off

hello<br /> I dont think the 94 had a bypass valve. I think it was a part of the T-stat assy. in 94 it should have the vernatherm and diaphram assy. you can use a 5/8 wrench(box end only) to remove the plastic nuts holding the sensors in place, remove the sensor and plase in a pan of water with a thermometer and hook up the ohm meter and see what temp the tan wire to sensor body closes.also remvove the t-stats and make sure all the moving parts can move. and use good wire ties at all hose connections.<br /><br /> good luck and keep posting

 

[sgcheek]

Re: 94 evinrude 200 bypass blew off

Thanks everyone for all the good info!!<br />Checked compression today--all 6 in mid 90s.<br />I can rest easy now---anything else now is minor.<br />SG

 

[Solittle]

Re: 94 evinrude 200 bypass blew off

sgcheek - You may not be out of the woods yet sorry to say. Last year I had one of the little water hoses that lie at the back of the motor (OMC V4) that is part of the pisser system let go at 4500 rpm (tie wrap came off). The motor started to run like crap. No overheat alarm.<br /><br />To make a long story short - Later I did several compression checks resulting in good readings - still ran like crap. Pulled the heads and found major damage in one of the cyl. Seems the little 1/4" hose acted like a fire hose and dumped a bunch of water into the carb resulting in severe detination destroying a piston, heads & scoring of a cylinder.<br /><br />It was nothing that installing a remanufactured powerhead did not solve after turning my wallet upside down and shaking vigerously. I hope your situation does not wind up this way but if you continue to have problems you need to pull the heads and have a look see.

 

[seahorse5]

Re: 94 evinrude 200 bypass blew off

The bypass valve came out with the new big block re-design in '93, which was the introduction of the Ocean Pros and Ocean Runners.