Kent Posted June 8, 2000 Share Posted June 8, 2000 I've got a question for anyone that wants to answer. It seems to me, ameture that I am, that a 16hp onan in a 4040 is not enough engine for the tractor that it is in. It verywell may be that I just can't get the thing running and tuned just right. When I got it running a year ago, the compression was at about 65 to 70 lbs. Is that enough? If not, what is the compression supposed to be. I know it probably needs new points and condenser and they will be going in very soon,if I can find some. Any suggestions or comments would be very helpful. Thanks in advance. Jayt Link to comment Share on other sites More sharing options...
StanS Posted June 8, 2000 Share Posted June 8, 2000 Jayt The advantage of 20 horses is that the engine won't work as hard as a 16 and would enjoy a little longer life. I run a 16 Briggs in my 4040 and am very pleased with the power. I use a 54" snow blade in 2d gear to keep 4/10 mile of dirt road open while the engine loafs. She pulls a rock boat so easy I have to keep looking back to make sure it's still there. The 10Hp gear and shaft Squire skids three 30 ft hemlocks through the woods effortlessly. If anything, the 16hp 4040 leads the life of Riley. Sorry, I can't comment on the needs of the Onan. Stan Link to comment Share on other sites More sharing options...
JCB Posted June 9, 2000 Share Posted June 9, 2000 What has amazed me since I acquired my 3410 Landlord is how MUCH it does with "only" 10 HP!. My prior mowing machine was a 42" deck 12.5HP Craftsman, and it was ALWAYS wanting for power. This tractor with a smaller engine, is capable of mowing fairly thick 6-8" tall grass in HIGH GEAR!! I can't imagine having the luxury of 16-20 HP, or needing it for something less than tilling, etc. Though I think part of the story is the relatively deep, open design of the mower deck. Brian L. Link to comment Share on other sites More sharing options...
Guest Posted June 9, 2000 Share Posted June 9, 2000 Hi jayt. If you compression is that low, you probably need to pull the heads and check for carbon buildup. All of those Onan's were supposed to be decarboned every 200 hours. If you can't find parts in your area, there is a Onan dealer about a mile from me. I'll be glad to get his name and phone # for you. Link to comment Share on other sites More sharing options...
JCB Posted June 9, 2000 Share Posted June 9, 2000 Jayt, the bore and stroke on my ac 720 is the same as the 4040 and I am getting compression of 105# so you may need some rings or valves or something. Also with the gearing in that machine at the final drive drop axel you have tremendous leverage and power. Both 16 hp and 20 should be fine. T. Link to comment Share on other sites More sharing options...
tej Posted June 10, 2000 Share Posted June 10, 2000 Thanks for the knowledge guys, it will help alot. jayt Link to comment Share on other sites More sharing options...
Simplr Posted June 10, 2000 Share Posted June 10, 2000 Jay..... Ive heard that the valve guides on that engine last either 200 hours or forever. If it doesnt run on 1 cylinder check the valve guides and seats. and if it doesnt seem to work........ forget about the tractor or pay 800 for a rebuild Link to comment Share on other sites More sharing options...
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