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Discussion Starter · #1 ·
We just put a tiny tach to our 07 and 08 60in exmark lazers for the first time. The 07 has 950hrs and was running full throttle without load at 3400, the 08 was at about 3500. we put them both up to the reccomended 3750 +/- 50 and they are screaming, well compared to before. Should we stick with the factory reccomendation or are we gonna blow em up. If this is how they should be I am pissed I went through spring with little balls...
 

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We got 15 Kaw28 with a 60 inch deck and there not one the same. 14 of them are junk.Mows like $hit...
 

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Just watch your oil level very carfefully, ESPECIALLY if anyone is increasing the rpm on an air cooled engine. Air cooled engines run hotter and oil is burned much quicker. You also may find that you may need to change it a little more often running at higher temps.
 

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3600 under the load of the blades, (engaged). Thats where I have always had the best service out the kohlers I run. Really if that want do it, then that extra in rpm is just useing more fuel for nothing. Thats just my prefrence, has always worked well for me.
 

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Discussion Starter · #8 ·
3600 under the load of the blades, (engaged). Thats where I have always had the best service out the kohlers I run. Really if that want do it, then that extra in rpm is just useing more fuel for nothing. Thats just my prefrence, has always worked well for me.
Thats about where they are under load. Ill double check em today, and maybe turn em down a bit still to be safe. thanks for all the help guys
 

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I mounted a tach next to my hour meter to keep an eye on the RPMs. I found the engine setup at 3600 RPMs. I was a little surprised since there is a sticker mounted right on the 27/hp Kohler stating 3750 +/- 50 RPMs. This was also stated as the engine speed in the Exmark manual. I set the RPMs up to 3750 and have not notice much difference in the performance or cut. Since there was not much advantage to the higher speed and I have been reading from various posts not to go over 3600 I am planning on backing them back down as soon as I get a chance. It is very simple to adjust but once you start the engine it is really hot near the muffler, which is right where the adjusting screw is.

I did notice that the Kohler does a great job of holding the RPMs. The RPMs are always the same with or without the blades engaged, even with running doubles.
 

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have a kohler 27hp that has 1750hrs on it thought the rpm's were a little low this spring, the mechanic checked it and tried to adjust it and couldn't get much more than 3300 out of it before the lever bottomed out on a nut near by, can you please help me with the way to properly adjust this engine, if not may send it out to another shop to see if they can get it right. my other lazer had the engine replaced at 1400hrs replaced a 25hp with a 27hp new engine runs at 3700, and I want both machines to run the same. both engines state the 3750 +- 50.
 

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If he was not able to get anymore than 3300 out of it, Hopefully they have adjusted the cable position first to ensure full pull. then it may be that the governor spring may be stretched/weak, or the governor may need to be reset. Its a matter of loosening the the gold colored L- shaped arm that the spring and linkage hook into fom the shaft. then move and hold the arm so the carb is wide open. then rotating the governor shaft coming up from out of the crankcase counterclockwise as far as it will go and then reclamping the arm tight to the shaft again. These engines with the gov set right and the adjusting bolt run in can easily hit close to 4000rpms if needed. On the exmarks and toros always shoot for at least 3650-3800, that way when the blade load and hydro loads hit, it does not bog down to low and kill your blade tip speed, still giving you a good cut and discharge peformance. If the current dealer cant get it any better than 3300, I would def swing by another and see what happens.

Remember decks these days are all about airflow, and a lot of it is all determined off blade tip speeds. Engineers figure this out by engine power/rpms, pulley diameters, blade lengths/design, belt wrap percentage, etc. If the rpms of the motor are off even 200-300rpms, it can make a noticble difference in the blades ability to stand the grass up and cut it/stipe it and discharge it properly.
 

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