Just wanted to leave a comment to help future DIYers troubleshoot their low RPM overheats. If the poppet gets stuck open, much of the cooling water is dumped, instead of being circulated. There can be insufficient flow to reach the top of the motor. In my case, the flow was enough to get a decent pee stream (outlet on the top of the port cyl bank), but not enough for the top of the stbd bank (which is offset higher than port, and the overheat sender is right at the top).
I have a 90 hp 2003 Yamaha. I know this is an old post but I'll add my 2 cents. You have to put the thermostats back in. Yamaha built them with the thermostat to control the water flow and pull the heat out of the motor. If the water goes thru too fast the water doesn't have time to pull the heat out. I went thru the same thing and that's what a marine mechanic told me and it fixed the problem. A Yamaha engineer told him that.
John Hassler thank you. I changed the water pump and it fixed the problem.I haven't put the thermostats back in yet but I intend to. I know Yamaha put them there for a reason.
I had a Suzuki 150 around the same year model which had a similar poppet valve. I was having the same issues you were having and installed new poppet valve with new thermostats. No more alarm.
I had same exact issue. Found I had to clean the water jackets. Went through same process you did until I had to clean water jacket. On the popit valve there is also a rubber gasket around the plastic cable if you get stuff stuck behind it it restricts the popit from work properly.
I took the water jackets off and only broke 5 bolts. Simple fix really, just take the head cover to a drill press with some Kobalt drill bits and drill out the stainless steel bolts left in them and retap with 5/16 standard tap. Problem solved. Just make sure you round out the water jacket cover bolt hole threads when you re-tap or, if you can find them, use partially threaded bolts. The problem was I couldn't find any 1 inch partially threaded 5/16 standard bolts, so I drilled out the water jacket cover bolt holes to have no threads in them (which they don't anyway). In the manual, it says to clean out the water jackets every year. Now, I'm replacing the poppet valve. Hope this solves my problem. My engine would run fine at WOT for about 5 or 10 minutes then go into reduced RMP mode.
Poppet HELPS keep the powerhead fully charged .....if it gets corroded or that chyt gets in the valve it will DUMP YOU WATER TOO SOON and the upper cylinders will COOK the pistons if you run too long at WOT......keep that valve clean and run a restrictor instead of a thermostat and give her chyt
The best thing you can do with these motors is run them in a drum or garbage can. Add some Dawn soap and some Simple Green...and let the motor run in the drum. You'll see the water start coming out of the top two ports.....You don't have that! The Muffs can't get it done man....
When using the earmuffs you lose most of the water through the prop., while in the water, the pressure of the water (lake,beach etc) helps send more water up to the jackets/piston walls/ etc. However...corrosion, thermostat, poppit valve and water pump all play a factor in overheating. If your overheating with earmuffs on, then one of the 4 I mention above needs attention. Unlikely it's the thermosensor ( which can fail but rarely). Every 5 years I remove water jackets, poppit valve, thermostat and clean everything by hand. You'll be surprised on how bad it looks even when flushing properly.
Very informative videoclip! I have a water pressure gauge installed in my '91 V6 Yamaha. I think it shows much earlier if a problem can occur in future. I connected it to the highest point of the power head, above the thermostats. Many years before, i had also a 115 hp yammi from '89. Never had any cooling problems. Seems there is less salt in baltic sea, right? :-)
I have a 1998 Yamaha 115 2 stroke similar to yours and my engine overheat alarm goes off after I run and higher rpm for a while (15 minutes), and I have a good pee stream, so I think my problem is similar to yours. Did what you are trying here (Flushing your engine with Salt Away) solve your problem?
Hey Cary, He said in his update above; "Not running hot anymore". I have the same motor as you (1998 Yamaha 115 HP 2 Stroke Model: 115 TLRW. I am having the same issues as you. (Never has been used in salt water) I will be changing the impeller, seals and thermostats soon. Might have a shop do it for me.
@@Fed-Up_Hallelujah Thanks. There is also something called the Pressure Control Valve (PCV) or Poppet value that you might want to check and clear out if it has sediment in it keeping it from opening or closing, since according to other information that I have read the PCV being stuck can also cause overheating. I am changing out the water pump impeller, thermostats, PCV, sparkplugs, and the gear case oil in my outboard since all of that is due for a check/replacement on my engine. I may also flush my engine with Rydlyme since I already purchased their portable flushing kit (PFK) and two gallons of their descaler, but if you haven't bought Rydlyme yet, I would not buy it because Rydlyme will eat away at the anodes if you don't take them off and their are four anodes within the water jacket or crankcase that are hard to get to. Salt away is probably better for flushing since it should help but it should not attack those anodes the way Rydlyme will and Saltaway is cheaper and easier to use.
@@Fed-Up_Hallelujah Chris, I am based in Titusville Florida and use my Sailfish bowrider boat with its 1998 Yamaha 115 (model: C115TLRW) in both fresh and salt water. Where are you based? My email is cary.j.peaden@gmail.com?
Just wanted to leave a comment to help future DIYers troubleshoot their low RPM overheats. If the poppet gets stuck open, much of the cooling water is dumped, instead of being circulated. There can be insufficient flow to reach the top of the motor. In my case, the flow was enough to get a decent pee stream (outlet on the top of the port cyl bank), but not enough for the top of the stbd bank (which is offset higher than port, and the overheat sender is right at the top).
I have a 90 hp 2003 Yamaha. I know this is an old post but I'll add my 2 cents. You have to put the thermostats back in. Yamaha built them with the thermostat to control the water flow and pull the heat out of the motor. If the water goes thru too fast the water doesn't have time to pull the heat out. I went thru the same thing and that's what a marine mechanic told me and it fixed the problem. A Yamaha engineer told him that.
John Hassler thank you. I changed the water pump and it fixed the problem.I haven't put the thermostats back in yet but I intend to. I know Yamaha put them there for a reason.
I had a Suzuki 150 around the same year model which had a similar poppet valve. I was having the same issues you were having and installed new poppet valve with new thermostats. No more alarm.
I had same exact issue. Found I had to clean the water jackets. Went through same process you did until I had to clean water jacket. On the popit valve there is also a rubber gasket around the plastic cable if you get stuff stuck behind it it restricts the popit from work properly.
I took the water jackets off and only broke 5 bolts. Simple fix really, just take the head cover to a drill press with some Kobalt drill bits and drill out the stainless steel bolts left in them and retap with 5/16 standard tap. Problem solved. Just make sure you round out the water jacket cover bolt hole threads when you re-tap or, if you can find them, use partially threaded bolts. The problem was I couldn't find any 1 inch partially threaded 5/16 standard bolts, so I drilled out the water jacket cover bolt holes to have no threads in them (which they don't anyway). In the manual, it says to clean out the water jackets every year. Now, I'm replacing the poppet valve. Hope this solves my problem. My engine would run fine at WOT for about 5 or 10 minutes then go into reduced RMP mode.
Poppet HELPS keep the powerhead fully charged .....if it gets corroded or that chyt gets in the valve it will DUMP YOU WATER TOO SOON and the upper cylinders will COOK the pistons if you run too long at WOT......keep that valve clean and run a restrictor instead of a thermostat and give her chyt
The best thing you can do with these motors is run them in a drum or garbage can. Add some Dawn soap and some Simple Green...and let the motor run in the drum. You'll see the water start coming out of the top two ports.....You don't have that! The Muffs can't get it done man....
When using the earmuffs you lose most of the water through the prop., while in the water, the pressure of the water (lake,beach etc) helps send more water up to the jackets/piston walls/ etc. However...corrosion, thermostat, poppit valve and water pump all play a factor in overheating. If your overheating with earmuffs on, then one of the 4 I mention above needs attention. Unlikely it's the thermosensor ( which can fail but rarely). Every 5 years I remove water jackets, poppit valve, thermostat and clean everything by hand. You'll be surprised on how bad it looks even when flushing properly.
Very informative videoclip!
I have a water pressure gauge installed in my '91 V6 Yamaha. I think it shows much earlier if a problem can occur in future. I connected it to the highest point of the power head, above the thermostats. Many years before, i had also a 115 hp yammi from '89. Never had any cooling problems. Seems there is less salt in baltic sea, right? :-)
I have the same motor .
I could see that yours has a connector for garden hose is something that you added or came original.
It came original. I think the older models didn't have it. I'm not sure what year they were added.
Can u send me a pic. Where got conect to make an aftermarket to mine thank. Tiburon4504@gmail.com
I Need ti add the same connector , can you send photos to do an aftermarket ?
Thank you antoniocesi@yahoo.it
GreAt video
Did the new impeller fix the issue? I have same issue alarm going off at WOT after a mile or so
Appears you have the impeller in backwards when you put the impeller in rotate the shaft clockwise
Going to have to clean the water jackets in the heads either by chemical or removal
Are you sure the sensor is good ?
Make one whick a evenrude 225 pls
Impeller is a once a year deal. Not replacing that, thermostats n flushing engine is just pure laziness.
I have a 1998 Yamaha 115 2 stroke similar to yours and my engine overheat alarm goes off after I run and higher rpm for a while (15 minutes), and I have a good pee stream, so I think my problem is similar to yours. Did what you are trying here (Flushing your engine with Salt Away) solve your problem?
Hey Cary, He said in his update above; "Not running hot anymore". I have the same motor as you (1998 Yamaha 115 HP 2 Stroke Model: 115 TLRW. I am having the same issues as you. (Never has been used in salt water)
I will be changing the impeller, seals and thermostats soon. Might have a shop do it for me.
@@Fed-Up_Hallelujah Thanks. There is also something called the Pressure Control Valve (PCV) or Poppet value that you might want to check and clear out if it has sediment in it keeping it from opening or closing, since according to other information that I have read the PCV being stuck can also cause overheating. I am changing out the water pump impeller, thermostats, PCV, sparkplugs, and the gear case oil in my outboard since all of that is due for a check/replacement on my engine. I may also flush my engine with Rydlyme since I already purchased their portable flushing kit (PFK) and two gallons of their descaler, but if you haven't bought Rydlyme yet, I would not buy it because Rydlyme will eat away at the anodes if you don't take them off and their are four anodes within the water jacket or crankcase that are hard to get to. Salt away is probably better for flushing since it should help but it should not attack those anodes the way Rydlyme will and Saltaway is cheaper and easier to use.
@@Fed-Up_Hallelujah Chris, I am based in Titusville Florida and use my Sailfish bowrider boat with its 1998 Yamaha 115 (model: C115TLRW) in both fresh and salt water. Where are you based? My email is cary.j.peaden@gmail.com?
Mine was doing that also had to get water jackets cleaned
u always flush it out after saltwater use I feel sorry for that motor his owner did not take care of it
I always flush after saltwater. Apparently the previous owner did not.
Make a dodge 440 into s 2 stroke with Yamaha port pattern
Can i buy this?
Are you referring to the motor flush?