Merc 135 Gets Hot Pulling Skiers

[bluebyyou]

I just bought a 1988 Searay with a 135 Merc (my first Merc) and it has a temp guage. Telltale puts out good water all the time and eng runs cool at high and low speeds but at 20MPH and 3000RPM temp shoots up to 190 degrees (usually runs at 145). Any ideas? Is there a thermostat on this motor?

 

[CU2NITE]

Re: Merc 135 Gets Hot Pulling Skiers

You may want to check the impeller and change stats, they open at 143 degrees. There are two one on each side by the top spark plugs. Best to get a manual, sold at this site. Good luck.<br />CU<br /><br />------------------<br />RUNNING THE MOTOR WHILE LISTENING TO THE HORN WILL MAKE YOU MORN!!

 

[JB]

Re: Merc 135 Gets Hot Pulling Skiers

Sounds like you are climbing hills in overdrive, Blue.<br /><br />I think you are overpropped for pulling skiiers.<br /><br />Good luck.

 

[bluebyyou]

Re: Merc 135 Gets Hot Pulling Skiers

Flat out it runs around 5500 RPM and 47MPH I'll probably do the impeller and have the mech check the stats. Are these do it yourself jobs with a manual? I work on Dirt bikes and cars but I've never touched my Outboards!

 

[rodbolt]

Re: Merc 135 Gets Hot Pulling Skiers

Hello<br /> if you can do the impeller you should be able to do the stats. yes anyone is capeable of repairing their own outboard if they carefully read and understand what they are going to do before they start the job. do the water pump as a complete upper housing kit. carefully inspect the lower base for signs of melting. replace it if it shows any signs of melting. replace the T-stats with the OMC self flushing type that uses a vent in the poppet. make sure the seal is placed corrctly on the t-stats or life will be sad. also change the pressure relief diaphram and make sure the valve seat is in good shape. after that make sure your propped right for skiing and let her rip. <br />Goodluck and keep posting

 

[bluebyyou]

Re: Merc 135 Gets Hot Pulling Skiers

Thanks for the replies, I guess the first step is to order the manual. As for the prop it's the stock Quicksilver 19P. The boat has a decent hole shot and runs in the 5500RPM range WOT, I'm afraid if I lower the pitch some enterprising teen (my son) with blow the engine. There is no warning horn on this engine (previous owner must have disconnected) so that's also on my list of fixes.