737 Kawa680 valve guide and pushrods.

   / 737 Kawa680 valve guide and pushrods. #11  
On most engines, you want your compression readings within 10% of each other.

The last pic would explain a lot about overheating to me.

Clean everything and hope the cooler helps.

Kyle,
I agree, all that old oil and filth will definitely restrict cooling.

Larry - does this engine burn oil? While the tip of the plug looks like it is running a little lean, (no brown on the porcelain), the plug base looks oil coated.

Do you know what jets are in the carb? The shop manual has the recommended jets for altitude.

Richard
 
   / 737 Kawa680 valve guide and pushrods.
  • Thread Starter
#12  
Kyle,
I agree, all that old oil and filth will definitely restrict cooling.

Larry - does this engine burn oil? While the tip of the plug looks like it is running a little lean, (no brown on the porcelain), the plug base looks oil coated.

Do you know what jets are in the carb? The shop manual has the recommended jets for altitude.

Richard

Richard, Since I replaced the crankseal, the oil loss is minimal, but there is "some" for sure. No smoke, running synthetic. I do not know how the carb is jetted. I will see if I can access the main jets easily and pin guage them to see if for some reason they are high altitude jets. We are at sea level, but not sure where this machine was purchased originally.
 
   / 737 Kawa680 valve guide and pushrods.
  • Thread Starter
#13  
Re: 737 Kawa680 valve guide and pushrods. - oil cooler

I added the oil cooler, took about five minutes more than an oil change. I forgot to open the drain on the drip pan, so pardon the oil spill. Torque per spec for the pipe joint fitting is 33 ft. lbs. Anyone have any ideas for oil temp. gauge or CHT gauge? Seems like cylinder head temps might be useful, wanting to have an idea when/if we should shut it down.

 
   / 737 Kawa680 valve guide and pushrods. #14  
Last edited:
   / 737 Kawa680 valve guide and pushrods.
  • Thread Starter
#15  
A google search came up with a lot of choices. This gauge is one of the lowest price ones I could fine for dual temps.

FALCON GAUGE C2-2 | C2-2 | Gulf Coast Avionics

It's not clear if this comes with the leads so you will have to contact the vendor.

I strongly suggest getting a dual temp gauge.

However if you prefer to go with one channel, here is a digital display unit that includes the probe:
CHT Digital PMD1XT Pyrometer Gauge + Cylinder Head Temp Sensor Kit WS



Richard


when you say two channel, you mean one sender for each cylinder instead of monitoring the hottest cylinder; right? I would tend to agree that Murphy's law would have the non monitored (cooler) head blow first.
I will keep my eye out for deals on CHT gauges. Seems like a nice addition. I noticed a guy on youtube made some alterations to the carb throttle shaft to allow more flow at WOT. He claims that the 25HP vs. the 23HP (that I have) is only a matter of oil cooler and shutter opening wider. I already installed the cooler, so wondering if I can safely tease a little more power to the blades with the carb mod. I assume I can get enough out of the mixture screw without rejetting. I still have not measured the main jet but will get to that soon.
 

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