running temp on power heads

**eli** · 09-24-2018, 10:35 PM

what is normal temp no poppit 1/8 in restrictor in heads
2.5 nik cylinders thanks

**flabum1017** · 09-24-2018, 11:18 PM

Depends on lake/river/bay water temp..... the hotter the water you running in, the hotter the engine will be. once you approach 180, you wanna go bigger in the restrictors.....

**Flatlander** · 09-25-2018, 06:22 AM

I run my Liberator with a 260 on the Eagle River chain, so water temps should be close to what you have. Last weekend running 7500rpm, 150 deg.

**eli** · 09-25-2018, 06:57 AM

I never see over 140 reading from the sensor on the head and its been that way since 2002. Fast forward i got my blocks done with new Nik and looks like all pistons got pinched from what a member said 140 too hot I think the Nik failed is causing condition 1 st pic nik peeling

**Flatlander** · 09-25-2018, 07:37 AM

140 is not to hot, not sure why the nic is coming off, it certainly does look like it is peeling. Was the piston/cyl clearance and ring end gap correct when assembled? What rings are installed? Cylinders out of round?

**eli** · 09-25-2018, 04:36 PM

11 thou feeler gauge on 1 side of piston ring gap 22/24 which is off spec
1st time i got blocks back ring gap was 16 in 3 hr rings came out as 30 thou
rings came out again at 28 30 thou in 12 hr running my bore gauge says 3.502/3 toast

**Motv18** · 09-25-2018, 04:42 PM

Older stuff runs hotter 140,s iirc the new stuff like my opti will run 85-90 wide open and 115ish idle in 72* water and 95 air.

**XstreamVking** · 09-28-2018, 05:53 PM

That cold with an opti and you can get cold seize. My optis run 125 on the smart gauge and 150-160 on the cyl heads....Got over 2k hours on two of them. T-stats are 130 deg.

**Motv18** · 09-28-2018, 07:14 PM

Yep, book spec temps. Smart gauge. Dads old Yamaha you didn’t touch after it run though ouch.

I think the defference is it is it runs more like a car coolant sensor vs, temp sensors in the metal of the cap/head. I would see hotter.

Heats good on the carb motors ceeps the fuel in vapor form instead of forming drops.

Back to the question anything under the buzzer buzzer is good as long as proper pressure is there.