View Full Version : Yamaha P165 thermostat

05-23-2006, 05:42 AM
"Hi all,

I have a old Yamaha P165 (8HP) which has cooling problems Is there a thermostat fitted to these engines - if so where is it? BTW - can't seem to get hold of a manual anywhere here in europe for this engine, can anyone help?



09-21-2006, 09:53 AM
Have a full spares manual if you require one. Have no problems with parts as long as you have the original Yamaha part no. Let me know if you would like a copyof the manual and parts list


09-21-2006, 11:31 AM
"Hey Neil Thanks for responding. I would be interested in a manual and parts list. Do you have a part # for the water pump? Are you in Europe? I live close to Calgary Alberta. Do you see a stream of coolant water when the engine is running, or does it exit through the exhaust? I finally got mine apart and the impeller looks OK. I assumed that because I didn't see any water, that the water pump was defective but now I'm not sure. The seal that sits above the water pump on the shaft definitely needs to be replaced. If you have a part # for that I would greatly appreciate it. Did you find out if these engines have a thermostat? I was under the impression that they just constantly circulated water via the impeller. Thanks again for responding I was beginning to think I had wasted my money on an engine I couldn't get parts for.
Have a great day.

09-21-2006, 12:48 PM
"Hi Greg,

This is indeed a bit of a coincidence - I do live in Europe (in Wales to be exact), but I have just returned from a 3 week trip to Canada (incl. Calgary, but mostly BC), it's is a beautiful country.

To answer your questions in order:

1)I can scan a copy of the manual for you if you would like, just make sure that your mail provider will allow large attachments! Otherwise I can send a photocopy by snailmail.

2) Yes I do see a stream of water when the engine is running - it exits from a small hole in the block just underneath the two cylinders, BUT if you have one of the older versions of this engine (with a blue coloured leg/transmission - mine is all white (leg and casing)) there is no tell-tale hole and you should be able to see some little spurts of water and exhaust coming out of the exhaust relief ports (two small little holes about 5mm diam) halfway down the leg. To answer this definitely however, can you tell me: If your engine is short shaft, long-shaft, or ultra-long-shaft (Sail drive). What colour(s) is your engine? and What is the serial number.

3. No these engines don't have any thermostats - there was some salt deposits clogging the water jacket in my engine.

4. Bear with me for a day or so - I'll get the Part No.s to you.

Also it is worth mentioning that I have discovered these motors were originally only marketed in Canada with the model name/no. P165. I'm not sure quite how some of them ended up in Europe or elsewhere. Anyway, they are identical to the Yamaha 8A - they differ only in colour and cover graphics - this might make it easier when you are searching for partshttp://www.marineengine.com/discus/clipart/happy.gif from a Yamaha dealer


09-22-2006, 12:31 AM
"Neil I can't thank you enough. I have not found any info on this engine except for that which you have provided. I would be extremely grateful if you could send me a scanned copy of the manual and parts list. The guy who sold it to me thought it was a 6hp, and both local Yamaha dealers do not have any listing for this engine in their computers. The model I have is for saltwater. the only # I could find on it is s24165. The leg is about 28-29 inches from the bottom of the engine housing where the leg begins to swivel. I do have two small holes on the leg that sputtered and spit a bit when running as you described. This motor has been painted at some time and has a lot of saltwater corrosion on the aluminum so I don't know what the original colour might have been. I'll probably strip it and paint it over the winter. Please send my your mailing address so I can send you a little token of my gratitude. You might have noticed my odd email address; [email protected] ("") I make pottery for a living, I'll send you a little piece of Alberta clay I'm glad your visit here was enjoyable. If you flew into Calgary you landed about 15 minutes from my house. If you come back again I'll take you fishing.
Thanks again

09-25-2006, 07:44 AM

Did you get my last email? Your mail provider won't accept large attachments. let me know what you would like me to do.


Fons van der beek
05-06-2007, 02:10 AM
"Dear Neil, I am also intrested in the manual for the p165 yamaha, irecently bought a console boat with this engine, and i have some motorproblems....
In a seperate mail i'send you an email account for emailmessages larger than 20 mb"

tony goodman
08-13-2007, 03:45 PM
"please help, my dad has picked up a yamaha p165 and has today got it running. he asked me to find out what size it is, but after having a quick look round on line i'm not having a lot of joy. some say 4hp then a 6hp. if any1 can help me determine this please contact me on [email protected] (""), it is all white, leg and engine casing with a red stripe. and if any one would like to email the manual it would be much appreciated http://www.marineengine.com/discus/clipart/happy.gif"

08-13-2007, 05:08 PM
Hi Tony The p165 is an 8HP I will try to send you the manual that Neil sent me.

Tom Dubr
08-22-2007, 02:10 PM
Hi my name is Tom and i also have a P165 That i can not find anything for if you guys could help me out it would be much appreciated

08-22-2007, 02:43 PM
"I hope Neil does not mind but the P165 8HP manual and parts list can be dowloaded from this link.

http://users.aber.ac.uk/nsm03/yam/ ("")"