1994 -225 2 stroke yamaha overheating

[Lloydramdeen]

Hey guys. Please assist !<br /><br />I notice That the motor is overheating at low speed or at idle and the alarm comes on. It would dissappear once the speed is increased at higher revs. The thermostats are okay. Does this mean that the impeller is going ?

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

dude.<br /> long time no see. I hope you are well<br />could be an impeller problem but more likely a pressure relief valve problem. replace the grommet and clean the grommet pocket. the block is not staying full of water at low speeds. replace the water pump kit if it has not been done recently.<br /> good luck and keep posting

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

Rodbolt, Yes all has been well.Thanks ! No problem "mon"..Hope you are keeping out of the way of the hurricanes.Charley passed 60 miles south of us .<br />Before I go pulling off the lower unit, I will certainly check the grommet, but first I have to refer to my "Clymer" to see what that is ..or simplier yet, where do I find it ?<br /><br />I have never changed the water pump kit and I have had the boat for two and a half years and use it on most weekends. <br />Waiting to hear from you.

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

your water pump is way overdue mon. the pressure valve is under the 2 bolt cover at the lower stbd side of the exhaust cover with the large hose on it. replace them both. clean the valve pocket and replace the grommet and do the pumpo. now would be a great time to change the t-stats as well.<br /> good luck and keep posting<br /> ps we dodged charley as well. Alex passed about 60 miles to our southeast. I hope the next two miss us as well

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

thanks . Rodbolt !<br /><br />Will do this on the weekend and give you an update.

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

Hi Rodbolt<br />We pulled off the lower unit..<br />Here's our findings<br /><br />1..We found the pressure valve and grommet corroded and we cleaned that up and replaced them..<br />2. The impeller housing appears scored so we are going to get a new one.<br />3. The impeller would seem sound but will still be replacing it with a new one.<br />4. There is a rubber gasket that fits on top of the exhaust housing on the top of lower unit ,like it has 8 corners. right beside the drive shaft; slides under the impeller housing. The tech says there was an aluminium bracket that fitted over the lip of the rubber gasket. That bracket is missing or it wasnt there from the last time the unit was removed. I am looking in the Clymer manual and it is not giving me a name for it. Seems as it is suppose to take the heat off the pump. I dont know for sure.What is the name of this bracket. ?<br />Thanks

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

the only rubber gasket that had an aluminium bracket is the small rubber dam at the fwd edge of the exhaust port. sits directly below the aft edge of the wear plate. sometimes the corrosion would lift the plate and cause low speed overheat problems. the large rubber seal that fits in the cavity if used on your model has no retainer. without looking at it its hard for me to say mon . anyway just replace the entire pump kit and all will be well. good luck and keep posting

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

Rodbolt, <br /><br />okay, yes I think thats the same thing I am referring to. Is that a part of the kit ? <br /><br />We were going to just replace the impeller alone and clean up the rest of stuff, but seems as we might as well get the kit .maybe the way to go mon.do you have a website where I can visit for these parts to get the right number?<br /><br /> Another matter,what's the difference between OX66/EFI and HPDI in the 225 models ?<br />Which is more suited for my neck of the woods ?.A couple of 4 stroke motors around but the expertise to fix them might not be the best here and besides they seem expensive to buy and to maintain<br />I am thinking of doing an update soon and would rather stick to the old evil; the old 2 stroke..<br />Thanks

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

dude mon. in your area I would stay away from anything direct injection. the standard EFI uses an O2 sensor that MUST be cleaned every 100 hours. the replacement is about 360. I dont like O2 sensors but we are stuck with them.<br /> other than that and cleaning the VST filter the OX 66 is not bad<br /> good luck.

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

hi Rodbolt<br />Problem sorted out mon !<br /><br /> Think it had to do with that aluminum guide/seal at the forward edge of the exhaust port which was missing .that was causing the overheating at low speed. We have also replace the pump kit, cleaned up the pressure valve as you suggested and did a sea trail and we are all ready again.<br /><br />Thanks a lot.also for the advice on the new engine.that's for next year as this one seems as it will last forever. Bought it about 3 years,with the boat in Key West and although it's a 1994 model seems like it did not have many hours . Think I should do a compression check on the cylinders before I spend all that money ?

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

dude mon<br /> I hope all is well today.<br /> a leak down test would tell you alot more about overall cyl condition. usually by the time a compression test says its bad its rebuild time.<br /> good luck and keep posting

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

thanks a million.. hope Frances does not come your way !

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

Rodbolt,<br /><br />Is there an independent water pressure guage kit I could buy for this model so I will be notified that the block is losing pressure instead of hearing the overheat alarm all of a sudden ? The yamaha present guage also comes on (blinks) suddenly and gives no warning !

 

[rodbolt]

Re: 1994 -225 2 stroke yamaha overheating

yes<br /> buy the kit from yamaha parts and accesories and it comes with all the tubing and fittings you need. good luck and keep posting mon

 

[Lloydramdeen]

Re: 1994 -225 2 stroke yamaha overheating

Thanks mon!