Yamaha 175 Cooling Sys - RodBolt you can say I told you so!

Osprey

Petty Officer 2nd Class
Joined
Jun 19, 2004
Messages
128
Hello<br /><br />Purchased 95 Yamaha 175 a few months ago. RodBolt you had encouraged me to deal with the cooling system. But I had "more important" things to get done.<br /><br />Today 15 miles out and heading for 50, overheat alarm goes off. Back to the dock at 1.2 knots with our tails between our legs.<br /><br />Pulled the lower unit, impeller with white internal plastic bushing had spun. Put complete impeller kit in. Pulled thermostats both frozen in open position, looks like for a long period of time. Pulled the poppet valve all gunked up, don't know how it was stilling functioning and this motor had been running great all summer.<br /><br />PS. Picked up two new fuel pumps while I was at it, cheap insurance.<br /><br />One quick question. I have also had some very minor oil leakage from the small drain/weep holes on the lower unit after motor sits on the trailer for a week or so. The oil is dark and quite thick, but don't think its gear oil. After pulling the lower unit, it looks like its coming from the main shaft bushing / seal thats located were the main shaft enters the motor / powerhead. It appears to be retained with a c-clip. Is this any problem to replace and will it likely take care of the oil leak?
 

bigbrownbuku

Master Chief Petty Officer
Joined
Sep 17, 2004
Messages
885
Re: Yamaha 175 Cooling Sys - RodBolt you can say I told you so!

thats burnt 2 stroke oil leaking from the gearbox drains. it leeches down the sides of the exhaust during long periods of inactivity.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Yamaha 175 Cooling Sys - RodBolt you can say I told you so!

hello<br /> that was most likly caused by the overcooling. I would imagine you have a lot of carbon in the exhaust now. that is why I tell people you can pay me now or pay me later. but the price of the pump kit is the same whether or not you buy pistons. I hope all is ok. yamahas are fairly tough. the bushing you refer to is a steady bushing used on 25 and 30" shaft motors. it will require periodic replacement. feel it carefully for cracking and for distortion. the corrosion builds between the bushing and the housing and crushs the bushing against the shaft.<br /> good luck and keep posting.
 

scottoz

Seaman
Joined
Oct 26, 2003
Messages
53
Re: Yamaha 175 Cooling Sys - RodBolt you can say I told you so!

rodbolt - when I bought my 93 115 yammie it had a good impellor but thermostats had been frozen open for years I think - mechanic put a heat meter on and it was running way too cool - am I best to attempt to clean exhaust/de-coke engine with a spray/somthing else?<br /><br />Thanks mate
 
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