Posted by KEB1 on December 24, 2007 at 16:23:01 from (63.227.112.114):
In Reply to: cub wont start posted by javan on December 24, 2007 at 12:40:49:
Start with the basics. An engine needs three things to run, fuel, compression, and spark in the right sequence.
Compression: Was the engine torn down far enough that the camshaft may be out of time with the crank? Pull the valve cover, take the spark plugs out, crank the engine over by hand, should be able to watch exhaust to intake transition (exhaust closing, intake opening) coincide with piston at top dead center on the exhaust stroke. If valve timing appears to be correct, do you have compression? Should run (poorly, but run) even with really low compression. If you have low compression, check to make sure the valve clearances are set properly so that they're actually closing.
Spark: Now that you have compression and have confirmed the valve timing, check the ignition. Do you have a spark? If not, check that the point gap is set properly. If still no spark, check to make sure there is power to the hot side of the coil, and that the points are opening and closing. If you connect a test light between the coil terminal connected to the points and ground, it will light when the points are open and go off when the points close.
If you have a spark, check to make sure its timed right. Bring #1 cylinder to the top of the compression stroke (put a finger over the spark plug hole to feel compression). Make sure the distributor rotor is pointing to the #1 plug wire position. If so, set the distributor timing so that the points just start to open at top dead center. The timing won't be exact, but it'll be close enough it should run.
Fuel: Now assuming you have compression and spark in the right sequence, check for fuel. If you crank for a while with the choke all the way closed, the plugs should be damp with fuel. If they're dry, check to make sure you have gas at the carb and the float level is set properly. You can also check for a manifold leak by putting your hand over the carburetor intake and cranking. If you don't get good suction, look for a leaking intake manifold (probably a gasket) that would make the mixture too lean to fire.
As I stated at the beginning, if you have compression, spark and fuel in the right sequence it WILL run. Maybe poorly, but it will run.
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 - Picking Corn - by Rick Nikolich. It was the day before Christmas shutdown at work and I asked our lead engineering expert Scott Andrzejewski what he was going to do over the holidays. He said that he had some corn that he still needed to pick with an antique one-row New Idea corn picker. Scott has a nice farm about an hour north of Lansing in St. Johns, MI. He wanted to get the rest of his corn in by the next day (Christmas Eve). We had about an inch of new snow on the ground and single digit temperatures. So in the bac
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[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.