Yamaha OX 66 200 HP Questions

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steffysdad

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I went out fishing yesterday trolling for stripers, and everybody came back from the fishing trip with an awful headache. If there anything that I can check ?? does the O2 sensor affect the excessive smoke ?? <br /><br />Motor is a 2000 with approximately 150 hours on it. The motor runs great but you can't hardly stand the smell/smoke from the exhaust.<br /><br />Any help would be greatly appreciated.<br /><br /> :confused:
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

lots of things to check. 5 years with 150 hours usually means its a neglected beast. if you look closly at the maint chart its hours or calander WHICHEVER OCCURS FIRST. there are a few things to check, ruptured fuel pump diaphrams will make it run rich, I reccomend new ones wvery 3 years or so, a bad plug cap can make it run rich, excessive fuel pressure can make it run rich. a bad temp sender will also make it run rich. all can be tested but the electrical stuff will require a digital voltmeter and the correct test harness. are there any other symptoms like fuel spots on the water when idling abnormal fuel consumption? also check the oil pump arm for proper clearence and the plastic clip for cracks
 

steffysdad

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Re: Yamaha OX 66 200 HP Questions

Originally posted by rodbolt:<br /> lots of things to check. 5 years with 150 hours usually means its a neglected beast. if you look closly at the maint chart its hours or calander WHICHEVER OCCURS FIRST. there are a few things to check, ruptured fuel pump diaphrams will make it run rich, I reccomend new ones wvery 3 years or so, a bad plug cap can make it run rich, excessive fuel pressure can make it run rich. a bad temp sender will also make it run rich. all can be tested but the electrical stuff will require a digital voltmeter and the correct test harness. are there any other symptoms like fuel spots on the water when idling abnormal fuel consumption? also check the oil pump arm for proper clearence and the plastic clip for cracks
 

steffysdad

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Re: Yamaha OX 66 200 HP Questions

rodbolt thanks for the info. today i did check the spark plug caps and they were in spec. going to try to check o2 sensor is thier a way i could make up a harness to check the o2 sensor? i did replace the fuel pumps 1 year ago. thanks steffysdad.
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

I guess but without the correct size pins its hard, the harness is not expensive.
 

fondafj

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Re: Yamaha OX 66 200 HP Questions

steffysdad,<br /> I could not get a harness locally and I was pressed for time so I soldered 2 test leads on the O2 sensor outputs. This works well but the leads need to be waterproofed if you leave them intact. Here is a link that explains O2 sensor operation http://www.boatsetup.com/O2sensor.pdf - but use the testing methods described here and not the torch method for testing.<br /> Both my O2 sensors tested bad (2 225's) and replacing them made a huge difference in low speed running and smoke. Although I had other problems as well, the O2 sensor replacement was the biggest change. A few weeks ago we went fishing on a 38 degree morning and I was amazed at the difference in the cold weather running with the new sensors.
 

Flipstick

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Re: Yamaha OX 66 200 HP Questions

Centless, how much were your O2 sensors and can they be purchased online.<br />I carried my sensor to the local dealer and they cleaned it free of charge. Used a torch to get it red hot to burn off carbon buildup and a brass wheel to clean tube. Cleaned O2 sensor did nothing to my Smoking motor. 2002 250 Ox66 w/ 300hrs. Runs great on the go WOT getting 4900-5000rpm but idle its smokin and fouling plugs. <br />Thanks for all yalls help been lurking around here for some time......great forum
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

why dont ya do a running voltage output test on the O2 sensor? will confirm or eliminate it as a possible cause.<br /> while your at it perform the oil link rod check, most are so far out its not funny. usually I have to clip 5 threads or so off the arm to get the lever to stop pin clearence correct. the bench test for the O2 sensor is a teat on a boar hog. <br /> but its time for a general engine check up to include fuel pump diaphrams,o2 sensor outputs and injector leakage tests.<br /> 5000 RPM is a bit low, that motor should be propped to 55-56 K.
 

Flipstick

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Re: Yamaha OX 66 200 HP Questions

rodbolt, the most rpm since new has been around 5200. I thought the same thing but you know dealers, say whatever to get the sale final and out thedoor. Is cleaning the O2 sensor by a torch good enough or does it still need a cleaning solution below the threads. I will look around for a harness to test it out also.
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

ya really cannot clean the sensor itself as its protected behind that metal sheild. its also possible to damage it by overheating it. the only decent test I know is to hook up a DVM to the sensor with the test harness, remove the airbox, and with the gearcase fully submerged in the water,not a barrel. start the engine and allow 5-10 min warm up then while watching the voltmeter cover the top air bypass hoole with your finger. the meter should go something above .8V when the finger is removed it should go to something around .3V then it should start scaling up and down between about .35V to .56V if it does not react or does not scale its bad.<br />also use your DMM to test the plug caps, and check the pump link rod adjust ment per the service manual. if you back off the idle speed screw you will have to reset the TPS voltage but I reccomend checking the TPS output anyway. the lower throttle shutter must be fully closed to check the oil pump lever to stopper clearence, easiest way is to dissconect the lower 2 throttle shafts.<br /> most pumps are out of adjustment.
 

fondafj

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Re: Yamaha OX 66 200 HP Questions

Flipstick,<br /> rodbolt's advice is right on --- actually he is the one that walked me through my learning experience. For purchase price... expect to pay in the $250 range. As far as the online availabilty -- there are a lot of options. I hesitate to recommend any one place as so far I have had spotty results ordering online. I purchased my O2 sensors locally as I needed them ASAP and my local dealer came close to the internet pricing.<br /> Steffysdad,<br /> The more I think of your statement of headaches by everyone, this sounds more like CO2 poisioning than just the annoyance of 2 cycle oil. Are you trolling with your canvass up? For 40 bucks or so I put a 12V CO2 sensor at my helm for that exact concern ... CO2 buildup while trolling in foul weather with the canvass up.
 

Flipstick

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Re: Yamaha OX 66 200 HP Questions

Well I took my motor in to local shop. They found two fuel pumps that were leaking. TPS was measuring .5??(suppose to be .3 right) Not exacly sure but the mecanic said it was set for 2500rpm. My O2 sensor tested good. Replaced my onboard fuel filter. Oil rod needed adjusting. I think it is idling better now than when it was new.... Thanks Rodbolt
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

actually I think the TPS setting on that motor is .5v plus or minus .02V. thats with the throttle shutter fully closed and off the idle stop screw.<br /> you dont set the TPS for RPM on that motor you set like the service manual says and it works.<br /> idle speed in neutral with the gearcase submerged is 730 RPM plus or minus30.<br /> timing should be about 5* ATDC at idle and 23*BTDC at wot plus or minus 2* on both settings.<br /> timing is controled by the TPS and ECU.<br /> see what I mean about the pump diaphrams? did they show them to you ?<br /> to close the shutter you can dissconect the top two shutter links or back off the idle stop screw and the linkage sync screws. set the tps to .5V, pink wire to orange wire, do the carb sync then with the gearcase submerged adjust the idle screw to 730 RPM.<br /> its also a good idea when checking the TPS to check the 5v reference before adjusting it. to check the 5v reference go orange to red. 5 volts plus or minus .25v.
 

Flipstick

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Re: Yamaha OX 66 200 HP Questions

Godbolt, They did exactly what you said to have done. I couldn't remember exactly the voltage he said the TPS was at. He just said it was abit high and it was set(guessing) at point making the computer think it was idling around 2500rpm. They gave me all the parts they replaced. I didn't see the diaphragm but I will take it apart and see. Motor runs like a charm. Out of the water RPM is around 1100.The mechanic seems to know his stuff. He only charged me $250 for all the work...not too bad I think. 2-FuelPumps,Onboard Fuel Filter, Dignoltsis and hour half labor. Damn labor has gone up abit $95 here in the panhandle, FL
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

wow<br /> but it will go up here soon. its gonna cost me almost 700 dollars just for another week of school and gas last year was about 1.20 and now its 2.40 a gallon.<br /> so I can only absorb so much and every other tech and dealer is in the same boat.<br />\ but everything is going up, LPG, gas,diesel. parts due to the price of plastics and electricity.<br /> in fact we were disscussing today as to raise from 75hr to 90 this year or go to 100hr in 07. I voted for 90 and if we get out of Iraq and gas goes back to 1 dollar a gallon as per Rumsfeld's TV promise, we dont have to lower the price so much.<br /> most the dealers around here try to opererate on a 30% margin.<br /> but the cost seems reasonable to me. <br /> the TPS explanation does not make sense, the engine gets its RPM info from the pulsers and the TPS gives throttle angle.<br /> a simple explanation is at .5V the ecu sees the shutters as fully closed, the CPS detects crankshaft phase angle(which piston is where) and the rulser coils provide information on RPM and assist in ign timing control.<br /> we know there is 35PSI of fuel waiting at the injector, we know that X amount of injector "on" time will deliver X amount of fuel.<br /> ok we are idling at 730 RPM. the TPS is about .62V we want to accelerate.<br /> now the TPS angle suddenly changes and goes to say 3.5V, the ECU is looking at that and at the RPM from the pulsers and the CPS.<br /> it knows that the values are not correct.<br /> it now adds fuel by increaseing the injector "on" time and adding a specified amount of ign timing advance.<br /> its looking for the Map values to null themselves.<br /> the ECU map sees the engine load through the TPS, the barometric pressure the intake air temp(for air density) and RPM. it will adjust fuel delivery and ign timing in an attempt to make the ECU map correct.<br /> the knock sensor gives info on detonation and if detected can add fuel and retard ign timing. the O2 sensor is giving the amount of O2 (unburned hydrocarbon comparison) information so the ECU is constantly making minor corrections to fuel mix in an attempt to hold a 14/1 air fuel ratio.<br /> thats a basic electronic EFI. most all speed density systems work that way. some systems dont use an O2 sensor. but all have to have a means of detecting throttle angle,crank phase angle and crank speed.<br /> aint but so many ways to do it.<br /> failure of the actual EFI stuff is rare. mostly its adjustments and mechanical failures such as a bad fuel pump diaphram. stupid computer cant detect that. stupid puter also cannot detect low fuel rail pressure due to a clogged VST filter.<br /> stupid puter cannot detect a dirty O2 sensor either and can lean out the air/fuel mix above 4000 RPM and smoke a piston.<br />and there is the twofold issue of running an OX 66 motor with a bad low pressure pump. not only is it leaking raw fuel with no oil into the crankcase causing a flooding condition the O2 sensor will pick it up as an over rich condition and lean out the incoming air/fuel to all six cylinders thus reducing the availible lubricaton even more.<br /> poof no piston and occasionally bang the rod cap is now hanging outside the crankcase.<br /> its all about the proper maint with a tech that cares.<br />and no the fuel pump is mention nowhere as a maint item, that comes from a few days experience.
 

rodbolt

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Re: Yamaha OX 66 200 HP Questions

not really I have just done it a bit, that coupled with programming and setting up CNC mills and lathes, working in automotive machine shops, 6 years as an FC in the USN and and I started off on automobiles back in the mid seventies,<br /> first 327 I built I could not test drive due to not being old enough to have a drivers liecens.<br /> work with this stuff a while and its all the same only the paint color changes.<br />and thats why they make service manuals.<br /> but almost all current production EFI systems work this way. some of the sensors change but the objective and the results remain the same.
 

titch

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Re: Yamaha OX 66 200 HP Questions

Have been reading this thread and has given me a good insite into my problem but do not know what the clearance is so could someone please advise me on what the oil pump lever to stopper clearence is for a 1994 yamaha 200hp
 
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