1992 Yamaha 200 TXRQ - Pressure Relief Valve?

[fletcherd]

Can someone enlighten me how a Pressure Relief Valve works? I've heard two versions:<br /><br />1. It's job is to CLOSE at higher RPMs to allow water to stay in the head longer so that more heat exchange can occur.<br /><br />2. Its job is to OPEN at higher RPM's so that water does not stay in the head as long.<br /><br />Please advise.

 

[seahorse5]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

The valve is closed at low speeds so that the thermostats keep the cylinder head and block temperature close to 140 degrees for better combustion and resistance to fouling plugs and carbon buildup. At high speeds, when internal combustion temps are high, the valve opens and water flows thru the block at a higher rate and the motor water temp stays cooler.

 

[fletcherd]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

So if the valve is stuck closed then the engine would not overheat at low RPM, but would overheat at high RPM? Thanks for the help!

 

[seahorse5]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

Parker,<br /><br />You are correct. By the same token, if it stuck open, you may overheat at low speeds since not enough water would reach the top of the block and cylinderheads.

 

[rodbolt]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

hello<br /> the valve contols water pressure at all speeds. if stuck shut there would be way to much water pressure at high speeds making gaskets leak and t-stats stick and all kinds of wired problems. if it sticks open at low speeds it will cause a loss of water pressure and an overheat at low speeds. some v-6 engines also have a tiny plastic restrictor under the power head. if the reman people did not reinstall it and the installer did not install it it will have the same effects as a stuck open pressure valve. best to clean the pocket and change the grommet every other year when you do the pump kit and t-stats.then it never fails and your always happy.the water flow comes to the pressure valve and telltale area of the exhaust cover before going through the power head. some larger v-6 motors with water cooled regulators use telltale water to cool the regulators. the excess pressure is dumped from the cover,through the valve,to the powerhead adaptor and out.<br /> good luck and keep posting

 

[fletcherd]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

Thank you both. Last Sunday afternoon I replaced the pressure valve, grommet, spring, gasket and cover. The old parts were very grimey and the grommet was "gummy". The procedure I used was recommended by a local Yamaha dealer and went like this:<br />1. Remove cover and pull out old valve, spring and grommet.<br />2. Take brass gun cleaning brush and ream out the hole were grommet was.<br />3. Take compressed air or water and flush out the block back towards the head and then to the same through the hose down to the lower unit.<br />4. Without new parts, put only the cover back on (may need to use new gasket & tourque=5.6 ft-lb's) and flush engine for a few minutes. This will flush any sediment that you've broken loose. Tattle Tail will be weak. Don't run too long (less than 5 minutes)<br />5. Pull the cover back off and THEN install new grommet, valve, spring and gasket.<br />6. With muffs on, run the engine again. Tattle Tail should be very strong.<br />7. Sea Trial boat to verify that engine does not overheat at low or high RPM.<br /><br />I did the above and will Sea Trial boat tomorrow. The tattle tail is as strong as a horse pissing on a flat rock. Also, I plan to start using SALT-AWAY on EVERY flush after every trip. Lastly, I'll be changing the pressure relief valve and grommet EVERY time I change T-stat's and water pump. Thanks again. Parker23

 

[rodbolt]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

dude<br /> find anther dealer<br /> its hard on head gaskets to run that long witout water.<br /> without the pressure valve in place the top of the block wont cant and will never fill with water. so it makes the #1 cyl sleeve golw red in a minute or so much less 5.sounds like another dealer that has no clue how the pressure relief system works. all you did was flush the water pump and tube. the water goes up the tube from the pump. through the power head adaptor into the block. there it goes to the exhaust cover any over pressure is dumped at the cover and never goes into the block. same with the tell tale water it never sees any other part of the motor. so when water pressure is low at idle and the hot horn is sounding its because there is NO cooling water around the sleeve for # 1 cyl.<br /> good luck and keep posting<br />PS the 3.1 litre has a different flow pattern through the heads but the relief system works the same.

 

[fletcherd]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

I truily apprciate your input and I'm sure you're knowledable, and what you say makes since. However, with all due respect, no cyclinder was glowing red hot during the very few minutes I ran it with water and no pr valve. The engine spec's out both in compression and tolerance as required. In fact from pulling the heads, the #1 cylinder looks very good, as does #2 through #6. Norfolk Marine actually gave me very sound advice. The engine sea trialed just fine. Thanks again.

 

[rodbolt]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

hahaha your the smarta** that couldnot figgure out a basic maint problem. but no worries me or someone like me will get your money in the end <br /> have a nyce day now ya heah

 

[JohnMadisonCT]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

Rodbolt: You are so darn correct when it comes to your average Yamaha dealer's knowledge of the Poppit Valve assembly.<br /><br /> I stopped by one to help me with my problem from last spring. The mechanic looked at me like he never heard of it before.<br /><br /> I diagnosed myself, followed the procedure, and the engine ran like a top.<br /><br />John

 

[ADedeluk]

Re: 1992 Yamaha 200 TXRQ - Pressure Relief Valve?

Rodbolt: You are so darn correct when it comes to your average Yamaha dealer's knowledge of the Poppit Valve assembly.<br /><br /> I stopped by one to help me with my problem from last spring. The mechanic looked at me like he never heard of it before.<br /><br /> I diagnosed myself, followed the procedure, and the engine ran like a top.<br /><br />John

I have a 1999 Yamaha V Max 150 outboard and here's my problem.
My starboard side 3 cylinders are running hot and my over temp light and buzzer comes on it seems to do it at low speeds but the port side is running cool. I have changed the impeller and thermostats and still have the same problem. Any info would be great !!