Water Pressure 1990 200HP PLEASE HELP

Got great help regarding another post, but yet again... I need help.<br /><br />History... Pressure readings dropped down to 4 pounds at an idle. Pulled boat out of the water for bottom paint and yearly maint. Got a sierra pump kit impeller / housing / 2 ring gaskets replaced my old pump and got 0 water pressure. <br /><br />Found that the pressure gauge was T'd off the tell tale line and plastic T was broken (assumed that was why low pressure reading on Gauge). Got new T and installed... still 0 pressure. Overheat after about 5 - 10 mins idle. Read forums... suspect poppet valve. Removed / cleaned and (looked fairly new) & reinstalled... 0 pressure still. Read more on forum, and replaced both T stats & gaskets. 0 pressure still. <br /><br />Blew air by mouth gently down hose to pressure gauge from hose at engine and had a reading on the gauge(pressure gauge apparently good).<br /><br />Read more on forums... Removed pump parts & Brought back all sierra parts and requested OEM Yamaha. Pump housing (and 2 o-ring type gaskets) / inside of housing (metal impeller encasement) / impeller / metal plate (under impeller), and gasket under metal plate. Also purchased brass fitting for the top of the higher bank of cylinders for direct attachment of pressure gauge hose(instead of T off of tell tale).<br /><br />Just installed everything. Watched VERY closely to make sure the impeller seated propely on the keyway, and that the housing properly seated with gaskets. Removed the piece of plastic and rubber hose sleve off of my original housing & installed on the new housing. Still ZERO Pressure....<br /><br />Had this engine for almost 1.5 years, and it has always been turnkey. Besides the overheat in my driveway 2 seconds... The engine has not overheated... Used almost every weekend. I can't think of what I am doing wrong. I'm using my CLYMER manual, and following all steps. The only thing I am wondering about is this small metal pin that came in the kit, I think it is to replace the pin that holds the housing in place on the gearbox, I did not change because the one there seemed fine. Also since I got tired of unbolting & re-bolting the gearbox, I only attached 2 bolts to test the pressure (maybe I need to attach all of them?)<br /><br />P.S. I put the brass fitting in at the top of the higher bank of cylinders, and 0 pressure still. I can remove the hose from the brass fitting, and water does not spray out of it?????<br /><br />PLEASE... Any suggestions would be appreciated.<br /><br />

Re: Water Pressure 1990 200HP PLEASE HELP

hello<br /> did you remove the rubber dam and the metal insert under the pump next to the exhaust cavity. sometimes corrosion will lift it and cause an air leak. then double check your poppit. the water pressure tap is supposed to go on the port bank.

Re: Water Pressure 1990 200HP PLEASE HELP

Originally posted by rodbolt:<br /> hello<br /> did you remove the rubber dam and the metal insert under the pump next to the exhaust cavity. sometimes corrosion will lift it and cause an air leak. then double check your poppit. the water pressure tap is supposed to go on the port bank.

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Went to go check the poppet & pushed the rubber gasket into the exhaust cavity. Had to remove the exhaust cover to get to it, and out of the many bolts, one snapped. I am just having a ball with this job. I will check the rubber dam, if I recall it looked in pretty good condition, no corrosion around it either. <br /><br />I ordered a new poppet valve, spring, & gaskets, along with 2 exhaust gaskets from this site (since I removed the exhaust to get to the poppet gasket that I pushed in), I also purchased the 3 pieces that (based upon the chart on this site) are used to link the pump to the inlet pipe leading up to the engine. I found it interesting that there were 3 parts on the chart, but I only had 2 on the old pump??? <br /><br />The two pieces I had were what appeared to be a small bit of hose that fit into the water pump outlet, and a cap that snapped into the top of the outlet that holds the hose down (I'm thinking I might have lost a part, would anyone know?). <br /><br />Since an air leak can cause an issue, should I bolt the entire gearbox on before testing the pump pressure (instead of 2 bolts)? <br /><br />When I asked the mechanic at the dealer, he mentioned the brass fitting for the pressure gauge should go on top of the higher bank of cylinders, which when facing forward in the boat is the starboard side, You mention it should be the port side. Is the dealer wrong? Please confirm. Thanks.<br /><br />Did some more searching and found another reference to Port as you stated so I will switch the fitting. Thank You.<br /><br />Would I be running to much of a risk if I just left that broken bolt in, I tried liquid wrench, wd40, and now a tourch... and I can get the darn thing out. Please let me know. Thanks

Re: Water Pressure 1990 200HP PLEASE HELP

have the dealer show it to you in the rigging guide.your making this waaaay to difficult. dont sweat the small parts on the water tube. odds are against ya. the grommet can be easily retrieved with a bent wire. do it to myself occasionally. remove the rubber dam on the edge of the exhaust cavity below the pump wear plate. clean the rubber and the metal insert well. for testing 2 bolts will hold the case on just fine. if the pressure valve grommet is not in the correct place it will dump all the water back down the exhaust tube. but the curiostity is killing me on why to mount the water pressure pickup on the highest cyl. I already know the answer to why they want the pressure tap on the port side I just gotta see what your "dealer" says <br />and whatever ya do leave the silly cone sealent in the garage. it has no uses on a yamaha. I myself use quicksilver perfect seal on the cover gaskets.

Re: Water Pressure 1990 200HP PLEASE HELP

Thanks rodbolt... Seems like you save many of my kind... wish I had asked for your feedback on the grommet thing before I removed the exhaust cover and broke one of the bolts located in the middle. Cant get the broken bolt out with penetrating oil and torch (tried for 3 days). Would it be a horrible thing to leave that 1 broken?<br /><br />Also... if the reason my pressure gauge reads 0 was due to the fitting being installed on the starboard side, I wont ask the dealer anything... I'll never go back there again! Are you saying that putting it in the starboard side would result in 0 pressure? HE WAS 100% CLEAR THAT I SHOULD DO THAT.<br /><br />Better Yet... If mounting on the starboard side would cause 0 pressure I'm at his doorstep when he closes....<br /><br />Thanks

Re: Water Pressure 1990 200HP PLEASE HELP

no the side of the fitting wont make any difference on the pressure reading. no you cant leave one bolt out. it will leak. however you can carefully drill it the 6mm tap size or to 1/4x20 tap size and either rethread it or heli-coil it. do that all the time as well. thats why I learned to retrive the grommet with a bent wire . I see the water pressure fitting on the stbd side all the time. doesnt matter block pressure is block pressure and can be tapped about anywhere. just increases the chance of the line breaking due to excessive bends and the rigging guide says put the pressure fitting on the port bank and the temp sender on the stbd. makes the water line have more gradual bends.

Re: Water Pressure 1990 200HP PLEASE HELP

I have used the plate as a guide while drilling out the broken bolt. If you are off a little when you get through, there is enough meat around the hole to allow slight reaming so the bolt will line up. I have also found the silly cone will cause this problem.

Re: Water Pressure 1990 200HP PLEASE HELP

OK... Purchased the 1/4x20 HELICOIL kit, and a good 1/4 inch bit, besides using the plate as a guide (which is a great suggestion I was worried about keeping steady), are there any other tips that you might give before I go for it this afternoon. Thanks in advance.

Re: Water Pressure 1990 200HP PLEASE HELP

use the drill bit size for the heli-coil tap. its on the tap. I use bullet point bits and have no problems. but I have been driiling them about 30+ years now. the key is a flat stud, use a file, and a good center punch mark and a decent drill with a good chuck and spindle bearings. that and a quality drill bit, dewalt makes some killer spin proof bullit point bits. the bullit points wont walk off center. would have been as easy to buy the 6mmx1.0mm heli-coil kit. but what ever kit you use follow the tap drill size marked on the tap. I dont use the plate because it inhibits me from watching the chip pattern on the drill. the chip patteren will tell you if your cutting speed is correct and whether its walking.

Re: Water Pressure 1990 200HP PLEASE HELP

Used IRWIN Spiral Screw extractor 5/32.Carefully and SLOWLY drilled the guide hole for the spiral extractor, but the spiral extractor did not work, however as a result of drilling the hole for the extractor I had a guide hole for my BLU-MOL Cobalt 1/4 drill bit. SLOWLY drilled out the hole to 1/4 size, and slowly tapped using the HELICOIL 1/4-20 kit tap, used the key to put in the thread coils and dry fit PERFECT.... Thanks... at least I can concentrate on the pump and the pressure now. Will keep posting as soon as I get my parts, the exhaust gaskets are back ordered (MAN if I only fished out that grommet.)

Re: Water Pressure 1990 200HP PLEASE HELP

OK Saga continues... checked the rubber dam (had loads of corrosion under it)cleaned it out. Removed the new pump housing to check the gaskets to make sure none slipped put everything back together as per CLYMER. Mounted the gearbox, and 0 pressure yet again. After about 5 mins, overheat alarm (immediately I shut it off). Removed the gearbox and connected the garden hose directly to the tube that goes into the pump, and without starting checked the pressure, and got over 30 pounds, tell tale peeing harder than I ever seen it. Hoped that i might have flushed something free, reconnected the gearbox and started once again... 0 pressure. Appears the new pump set up has something wrong... what... I duno... but I'm at wits end... Rodbolt I know you mentioned me making this to complicated, but I don't know what else to try. Even before I went to replace the pump I had decent pressure I just did it as preventative maintenance....??????????

Re: Water Pressure 1990 200HP PLEASE HELP

Just a double check - When installing the pump housing over the impeller, are you sure you are turning the main shaft in a clockwise direction? <br /><br />Did you replace the poppit valve rubber grommet, plastic valve and spring or just clean and re-intall. If Poppit was not sealing much of your water pressure could get dumped there.<br /><br />Have you rechecked the impeller to be sure the drift key is in place and has not tornout the slot it rides in on the impeller? Was drift key replaced along with the impeller?

Re: Water Pressure 1990 200HP PLEASE HELP

In order...<br /><br />1)Yes turned shaft clockwise to seat impeller in housing.<br /><br />2)Just Cleaned at first, then secondairly replaced grommet, new style poppit(rounded at the end pointing towards engine spring & outer gasket(for housing).<br /><br />3)Yes (saw posts on impellers slipping) removed impeller and key slot was in tact, actually tested turning the shaft and trying to hold impeller stationairy, and was unable to. The drift key came with the impeller.<br /><br />I know I have got to be doing something stupid, I might just opt to bring the gearbox down to the dealer. As Rodbolt said before, and as I have seen on other posts, this procedure should not be brain surgery. If you have any more suggestions they would be appreciated. Thanks.

Re: Water Pressure 1990 200HP PLEASE HELP

Did you side by side compare the new metal impeller housing to the old one. There are some differences between engine models/years. You could get a kit which had the correct impeller but the wrong housing for your model.<br /><br />If you take it apart again. Check that the output slot in the metal housing and small metal alignment tabs on the top of the housing match your old unit and that they properly align in the outer plastic housing.

Re: Water Pressure 1990 200HP PLEASE HELP

The old and new match exactly, <br />BUT<br />I have an embarassing update. I live in a waterfront home & have a set of flush muffs I leave on my dock, when I asked my son to get the muffs he got an old pair from the garage....(you know where this is leading) I dropped the gearcase AGAIN and attached the muffs to do a visual on the pump housing (see if there were any cracks or defects) I noticed a HUGE difference in the pressure I got comming to the pump just by squeezing the flush muffs slightly. I Just came from buying a new pair of muffs & low and behold my pressure looks good. It takes alot to fess up to this after all the stuff I've been through... (could have said a hairline crack in the housing...) but if it helps the next newbie wana be Yamaha OB mechanic so be it.... Thanks to everyone that pitched in..... Sure did learn a bunch!<br /><br />P.S. I can change the pump with my eyes closed now.

Re: Water Pressure 1990 200HP PLEASE HELP

Just glad everything working right now. Happy Boating.