risers too hot? affected by timing?

[pontosquantos]

hello,
i have bit the bullet and bought a 1986 rinker fiesta vee 250 with a mercruiser 260, cannot locate serial #. alpha one se106 leg. this is a close water cooled.
i am wondering if my risers are getting too hot ? i used a I/R gun to chek the temp. the engine maintains a steady temp of 168 F while my risers have a temp hight temp of 155 F port side and 131 F starboard side. i have removed and inspected them there is very little corrosion, almost new. heres where it gets abit weird. when advancing my timing the temp is 134 F port side and 131 F starboard side, even though i adjust the idle mix screw to match the same RPM as before i advance the timing. what is the proper operating temp of risers? thanks in advance for your responce.

 

[Bt Doctur]

Cool enough to keep you bare hand on it for 15-20 seconds

 

[alldodge]

hello,
i have bit the bullet and bought a 1986 rinker fiesta vee 250 with a mercruiser 260, cannot locate serial #. alpha one se106 leg. this is a close water cooled.
i am wondering if my risers are getting too hot ? i used a I/R gun to chek the temp. the engine maintains a steady temp of 168 F while my risers have a temp hight temp of 155 F port side and 131 F starboard side. i have removed and inspected them there is very little corrosion, almost new. heres where it gets abit weird. when advancing my timing the temp is 134 F port side and 131 F starboard side, even though i adjust the idle mix screw to match the same RPM as before i advance the timing. what is the proper operating temp of risers? thanks in advance for your responce.

Don't see an issue with the temps your reading on exhaust risers except the 168 steady for the engine. If you just come off plane and it's 168 that's ok, but your engine should have a 140 degree thermostat. So if your running a 160 thermostat change it out, unless your an EFI which for an 1986 would me a big change

 

[Scott Danforth]

closed cooling is usually a 160F thermostat. depending on your heat exchanger, most of them have a bit more flow to one manifold than the other on the discharge side. I say you are fine.

 

[Bondo]

hello,
i have bit the bullet and bought a 1986 rinker fiesta vee 250 with a mercruiser 260, cannot locate serial #. alpha one se106 leg. this is a close water cooled.
i am wondering if my risers are getting too hot ? i used a I/R gun to chek the temp. the engine maintains a steady temp of 168 F while my risers have a temp hight temp of 155 F port side and 131 F starboard side. i have removed and inspected them there is very little corrosion, almost new. heres where it gets abit weird. when advancing my timing the temp is 134 F port side and 131 F starboard side, even though i adjust the idle mix screw to match the same RPM as before i advance the timing. what is the proper operating temp of risers? thanks in advance for your responce.

Ayuh,.... Welcome Aboard,..... How old is the impeller in the drive,..?? The Alpha 1 impeller is marginal for a closed system, even with a fresh impeller,....

 

[alldodge]

closed cooling is usually a 160F thermostat. depending on your heat exchanger, most of them have a bit more flow to one manifold than the other on the discharge side. I say you are fine.

Your right Scott, blew right past the closed cooling. My mistake

 

[pontosquantos]

Thanks Guys,
I do not know how old the impeller is. I am guessing by the response is that it is a little on the high side as far as what the temp should be and that I should start by changing the impeller.