john deere 755 tuneup questions

[Jaymien]

Hi all, I'm new to this site and wanted to thank you all for such good info posted here.

I've just got a really clean john deere 755, 2wd, with 60" mmm, 1000hrs. first thing, i was going to replace all the fluids and gear/motor oil, air and fuel filters. Is there anything in particular anyone would check/replace when first acquiring one of these? and second question is, i live at about 8000 feet and i bought it from about 1000'. running at 1000' there was no smoke, but up here in the mountains there's a bit of smoke at start up and a small amount when it's running. i guess it makes sense that it would run the equivalent of a rich mix here (more fuel) but wondering if it needs a fuel adjustment for higher altitude if that it even exists

thanks again.

[Dennisfly]

I think you are on the right track with fluids and filters. Your altitude/mixture question, I have no clue. I have an 855 and one thing I found is that the fuel pickup in the tank is a hard line that goes through the fuel gauge sensing panel on the tank with several inches of neoprene line and then a filter screen on the end of the neoprene. The neoprene rotted and fell off of the hard line, so the fuel was not passing through the filter screen or the neoprene line. When the fuel dropped below the hard line level (about 1/3 on the gauge) you would run out of fuel.

You may also want to check and adjust the valves, as they have mechanical lifters. I bought an engine CD off of EBAY for about $30 that has procedures and specifications.

[Jaymien]

thanks for the tip about fuel line. what would indicate valves need adjusting...other than some smoke at start up, the motor seems to run and sounds good.

damien.

[roush9799]

I always wondered why I ran out of fuel on my 855 right before my gauge would touch the red. I bet I had the same problem.

[Dennisfly]

thanks for the tip about fuel line. what would indicate valves need adjusting...other than some smoke at start up, the motor seems to run and sounds good.

damien.

I haven't looked recently, but I believe that there is an hourly interval specified to check and adjust the valves. It is probably a long interval, like 1000 hours. With time, they would typically tend to become slightly loose (too much clearance). This would result in more valve noise (tapping sound), slightly less power, and maybe more pounding of the valve train components. If the valves are too tight, it could cause them to burn.

You have to remove the valve cover, rotate the crankshaft to the proper index mark, check the appropriate valve clearance with a feeler gauge, and if necessary, adjust with a wrench and screw driver.

It's not particularly difficult, but if you haven't done it before you might want to get someone to walk you through it.

[Jaymien]

Thanks dennis, i will inspect the valves. i'm finding that the machine actually pretty easy to pull apart, valve cover should be easy. also, you nailed it on the fuel pickup. i pulled the front hood bracket to get at the fuel tank and sending unit and sure enough the hard line is about 6 inches from the bottom of the tank and the fuel line, or rather pieces of the fuel line and filter are at the bottom. i could imagine how these bits of decayed fuel line could get pulled in. the whole pickup assembly is close to $90 at dealer, so I think i'll just add some new fuel line, new gasket and get a new screen. there's a bit of corrosion on the metal hard lines...you thinks it's a big deal to clean it up with some steel wool and re-use.

damien.