If no "coffee grounds" in the timing port area, I would check a few other things before tearing it off.
Bubbles obviously = air. UNLESS the IP shaft seals are bad (which would lead to diesel fuel in the crankcase), there's gotta be another explanation for air getting in.
How full is the fuel tank? Obviously if it is near full, the fuel level is above the lift pump and the fuel filters and any leak that would admit air SHOULD be leaking after shutdown, either externally, or internally (fuel lift pump leaking into crankcase).
That being said, I have a 4020 I don't put many hours on a year, so there's not much fuel in the tank because I try to use up the summer fuel, then put #1 in for the winter, and the other way around.
For YEARS, if it sat a while, I'd have to use the manual primer, and bleed air out at the filters.
A couple of years ago, I finally replaced the lift pump (even though there was no evidence of diesel fuel leaking into the crankcase).
Problem solved.
I would take the return fitting/valve out of the pump cover, and check it for debris (there's a glass check ball in there), then temporarily install a length of clear tubing between the fitting and the return line and start it up and check for bubbles while it's running, indicating air is getting in the primary fuel system.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Tuning-Up Your Tractor: Plugs & Compression Testing - by Curtis Von Fange. The engine seems to run rough. In the exhaust you can hear an occasion 'poofing' sound like somethings not firing on all cylinders. Under loaded conditions the tractor seems to lack power and it belches black smoke out of the exhaust. For some reason it just doesn't want to start up without cranking and cranking the starter. All these conditions can be signals that your unit is in need of a tune up. Ok, so what is involved in a tune up? You say, swap plugs and file the points....now tha
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.