Engine RPM Drop in Heavy Mowing

[IthacaJeff 151]

WH'ers

I've been mowing some heavy grass and weeds with my 310-8, sort of doing a

bit of brush-hogging. Even with only taking half a swath with the 42" RD deck, and

the throttle maxed out, the engine slows down more than I like. The question is,

what is the lower limit on RPMs under load? Anyway to keep the RPMs up without

stressing the engine?

What would be the best way to measure RPMs while under load?

Thanks,

Jeff in Ithaca

[travisg84 1]

I would mow with the deck up don't even drop the lever. Also make sure you have the belt on the bigger pulley on the pto. I'm not sure what gear you are mowing in but try slowing down also. I've gone as far as mowing in low range 3rd for heavy patches.

[lotus1967 0]

If it's an 8 speed, have you gone to low range? I can't imagine it bogging down in 1st, or 2nd low. I would also suggest sharpening your blades for this job.

Aside from that, and not knowing how high the grass really is, could the tall stuff be restricting air to cool the engine causing overheating and resulting power loss.?

Don't know if any of this makes any sense, but just brainstorming.

Even my 418-8 struggles in some grass at times. Low range always seems to solve the problem.

[hodge 6]

It sounds like you are just at the horsepower and torque limit of the Kohler 10 horsepower. Before you do damage to your engine, work within the parameters of what you have. In other words, mow what a 10 horsepower will mow, not a 16. That is an excellent engine, with lots of torque, but it does have its limit. If you overwork it and overheat it for long, you will do damage. I love mine, and have a lot of faith in it, but I wouldn't try to do what my 520 would have done.

[kpinnc 10,981]

My 310-8 mows very well with the 42 SD deck, but it does work pretty hard in the heavy stuff sometimes. The suggestion to use low range is a good one, but if it's still hard on it, I'd definitely look for a bit more power than the 310 has. The 37SD deck is a much better match to your tractor if power is an issue.

Mine would run out of power fairly easy before I overhauled it. After that, it has power to spare compared with before. I didn't have any trouble with the engine smoking too much, but the engine compression was way below what it should have been. Might be worth looking into.

Also make sure you have the belt on the bigger pulley on the pto.

This would result in higher speeds for the blades, but will place even more strain on the engine. I'd stick with the smaller groove for more power, at least for this particular use.

Kevin

[can whlvr 991]

I have blown up 2 engines on my 308-8,the original 8 hp kohler magnum,totally destroyed the engine,next motor was a rebuilt 8 hp (coulnt afford a bigger one at the time)it to blew up cutting heavy grass,i have a fair bit of grass to cut,I now put a 13 hp in it and it is almost unstoppable,like my 14 hp kohler,but i agree,use the machine accordingly or it can cost you

[IthacaJeff 151]

Gents,

Thanks for the suggestions. My blades were sharp (just sharpened), I mowed

in 1-high and even 2-low, and though it cut, I may be stressing the engine too

much. I'll leave the belt on the factory recommended PTO pully. . . that just seem

safe. In sum, I'll eave the 310-8 to do the job of a 10 hp and look for a bigger

tractor!

Jeff in Ithaca

[hodge 6]

Gents,

Thanks for the suggestions. My blades were sharp (just sharpened), I mowed

in 1-high and even 2-low, and though it cut, I may be stressing the engine too

much. I'll leave the belt on the factory recommended PTO pully. . . that just seem

safe. In sum, I'll eave the 310-8 to do the job of a 10 hp and look for a bigger

tractor!

Jeff in Ithaca

See- it isn't so hard to justify another tractor. You have to preserve what you have since they aren't made anymore, and different tractors fit different needs. That's our story, and we are sticking to it! :thumbs2:

[travisg84 1]

See- it isn't so hard to justify another tractor. You have to preserve what you have since they aren't made anymore, and different tractors fit different needs. That's our story, and we are sticking to it!

That's the reason I bought a second. It just didn't seem right to make the ol 312 mow and drag the garden cart around.(Pretty weak I know, but it got me a C-120A) :thumbs2:

[hodge 6]

From the wisdom of my father, "You can justify anything if you want it bad enough".