yama 115 v4 2stroke overheat

[defcondaze]

i took off lower unit on 2 stk 85' 115 hp engine<br />got water pump kit , installed , twice ...with muffs on lower still removed from powerhead water comes out where the drive shaft comes out ... is it supposed to ?, also comes out a small hole in the pump housing(this hole looks as its supposed to be there tho)<br />installed this on engine water flows out teltale<br />after running for about 10 min the alarm goes off( what alarm i duno dont have gauge) i stopped the engine left key on (buzzer still sounding)i remove the right side thermoswitch pink wire .. and reconnect and the alarm goes off ... start engine again ... runs for another 10 min no buzzer goes off than i shut down<br />is there anything else im supposed to replace with the water pump? , i changed the t-stats one tsat houseing is cracked and does dribble a little water (i guess this means the t-stats are working) part is on order . does this mean that there is good water pressure ?<br />also ... i have no remote oil tank installed ,gas is already mixed 50:1 and the resorvoir tank is half way full with oil , would this cause a alarm ?<br />keep in mind this engine was in the back of a truck for a couple years just sitting .... engine cover was on <br />owner says no problems with engine other than shift shift (which made him just buy new engine)<br />please help

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

have you cheked the pressure valve and replaced the grommet after carefully cleaning the grommet pocket ?

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

pressure valve is where ?

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

the t-stat housing looking thing at the lower stbd side of the EX cover. two 10 mm hex bolts hold it on.<br /> ill take that answer as a no <br /> its easier if you answer questions directly and dont make us guess.

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

i wasnt sure if u ment the valve under the spring in the tstat houseing ... ill check that tomorrow .. hopefully part in stock, also will test overheat warn light

 

[notarealone]

Re: yama 115 v4 2stroke overheat

I have the same problem after replacing the waterpump in my 115 Yamaha 1988. Did you find the grommet he was talking about? Did it fix the problem?

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

went to check today , could not find , was raining also ........ i dont see any cover on the exhaust cover

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

look down low on the flat plate between the banks. there is a 1" hose from the pressure valve to the power head adapter.<br /> someplace about now you should really look into a service manual.

 

[notarealone]

Re: yama 115 v4 2stroke overheat

I found the hose. It is directly under right lower magneto. It connects to the thermostat housing and then the lower engine housing. It also has the pee hole hose attached to the underside of the t-housing. I am using a Clymer shop manual and it does not talk about or show any grommet. What is this grommet and what does it look like.<br />I do need to clarify that my waterpump works fine at high speed, but under 1700 rpm the engine will overheat and the buzzer comes. When I first restart the motor, there is no water coming out of the pee hole until I rev it up. I recently did a de-salt cleaning again, could something have plugged up the works somewhere from that?

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

two normal causes for low water pressure in a V yamaha outside a melted housing are a bad pressure valve grommet or the rubber dam under the water pump wear plate. the dam holder gets corrosion and when the wear plate is replaced it cant seat properly and creates a small leak. the pocket the grommet sits in will build up and cause the pressure control valve not to seat and dump water pressure causing the top cyl to lose cooling water. both dont occur if the maint schedule of inspection at the ANNUAL or 200 hour,whichever occurs FIRST, service is followed.<br /> if the powerhead is a replacement there can be another source as well. the tiny plastic restrictors on some 2.6 blocks may be missing.<br /> to clean the pressure control valve remove the housing,spring and valve. remove the grommet that is the valve seat. use a hooked pick and carefully clean all corrosion. carefully reinstall a NEW grommet. it has to seat on the lip of the cover and dont drop it inside the cover. if you do post before taking further action. if the cover gasket is ok wipe it with some sealant like perfect seal and reinstall the valve,spring and cover.<br /> for the rubber damn it will require removal of the pump and then the dam and dam holder for a careful cleaning.

 

[notarealone]

Re: yama 115 v4 2stroke overheat

Will do. Thanks for all the help. Can you tell me the most common cause of water contamination in the gear case? I have a 1988 V4 115 Yamaha. No replacements have been done to this motor. It's absolutely in primo condition. These are the first problems I have ever had with it.

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

ok still cant find this pressure valve and no where in seloc manual is there a mention<br />

<br />also ran the engine again .... lower unit off , water hose straight up the water tube ... alarm goes on after 20 minutes ... now i have 4 wire connects under the carbs a black , grey, pink , orange . you said the grey wire was the ground for the overheat warning light ?... i hooked light bulb to batt and grounded on the grey wire .. nothing ... also nothing from all those other wires ...

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

wow never seen an 85 without the pressure valve. are you positive its an 85 powerhead?<br /> I told you the gray wire was the GROUND signal. it will ground to light the light. the other side of the light must be at a + potential or the light wont work.<br /> maybe Ray can shed some light on the valve. I had heard that an early production run of the V6 motors had the valve in the heads with the t-stats, but I never saw any.<br /> I hope you have not fried anything playing with wires. the black is ground, pink is ground signal for the alarm, orange is for trim indicate.<br /> you should have two more connectors as well a 2 wire with green and greenred. the green/red is the ground path for the low oil in the engine tank lamp and the green is the ground path for the green lamp for oil level in the system.<br /> the other connector should have a blk,blk/red a blue and a brown.

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

ok more pics .....<br />should this be connected ?<br />

<br /><br />front wires<br />

<br />left wires <br />

<br />and what is this covering ?<br />

<br /> and why did they use flat screws to keep it on

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

also did find pressure valve ... only in the manual for a v6 engine looks like .. seems like what ever manual i buy is always missing information on what i want to know

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

how do i rig up this light to a potential + ?

 

[rodbolt]

Re: yama 115 v4 2stroke overheat

the first pic, the green and the black connectors should not be plugged together<br /> one is for the oil alarm functions on the tach and the black one is for the remote oil tank transfer pump and level indicator.<br />never tried hooking just a lamp up. I always used the tach. but when the alarm triggers for overheat the warning module takes the grey wire to ground potential and allows a current path. if I can find one of my antique manuals ill look and see if its 12vkey on positive on one lamp terminal and the gray lead to the other. I think thats how the original 3 lamp tach was wired but I cant remember.<br /> can ya post me the engine model number ?

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

115etlk

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

im pretty sure its orig powerhead

 

[defcondaze]

Re: yama 115 v4 2stroke overheat

..............any info on rigin up those warning lights ? and what is that cover for in the last pic ?