idle

[jdfan]

Hey all. i have a 74 JD300. runs like a top. only problem is when it idles it wants to shut off. can anyone help me with this? i'm use to playing with large diesel engines with injectors.

[harleysportster]

It sounds like you need to adjust the low speed air-screw. There may be a decal on the botttom of the engine cover with all the carb settings.
Here is a lnk to the service manual covering your model. It is a large file, be patient.
http://www.vintagesnow.com/John_Deere_files/sm2100.pdf

[jdfan]

here's another question. When i have the track off the ground she runs well. doesn't bog down. when the track is on the ground i have no power. machine will not moved. i checked my plugs and they are good and wet. did i mix the gas/oil too rich? clutches seem to be alright. i thought maybe the brake was on but it's free. it was running good until i added gas. the guy i bought it from said to mix it 35:1. i did more like 40:1 with some fuel stabalizer. need that here in the great white north.

[JDT]

You sure it is hitting on both cylinders?

[jdfan]

funny you ask. i just came in from playing with it. i get spark on both but i noticed the one plug a little wet. the cylinder on the recoil side is good and dry. i have to get my multi meter so i can check out the firing rate on each plug and compare. do you think i might have bad rings?

[harleysportster]

Check compression.

[jdfan]

that is my plan. just have to find my tester and adaptors. what should the pressure be and what are the tolerances on these?

[jdfan]

compression is 110 recoil side and 115 on clutch side. little low eh? think i read it should be between 135 and 170PSI, with no more then 10PSI variance. i've taken my carb apart and cleaned it up. looked pretty clean but there is always some gunk. i have good spark when i pull it over. plug on clutch side is always a little wet even after running for sometime. is that side getting too much fuel and it's just flooding itself?