Cranky K341

[JPrattico]

Sometimes, a brand new spark plug will work when you test it outside of the head, but once you install it into the head it won't spark under the compression like it should.

 

[Jim Saunders]

Gary this is all good stuff. Yes, it does smoke at first and then runs fine. I don't know if I have a condenser, it's electronic [point saver] type system? David Kirk system? Anyway, you make good sense when you state that I should check the electrical system. Probably start with the ground and work from there. There is a splice on the plug wire?????? Thanks for all the help!


Jim

 

[dschwandt]

Id say there is your issue right there.
Get a new plug wire.

Does Dave's ignition module flash each time the engine goes though a crank cycle?
it should, and it should blink right when the cylinder reaches then S mark on the flywheel.
Locate and highlight the "S" and "T" marks on the flywheel
I usually use a white/silver magic marker.
Have you verified this??

Remove the point cover and verify, reset points to this and don't worry about the gap.
You can check this with a test lamp or VOM as well.

 

[gary noblit]

Gary this is all good stuff. Yes, it does smoke at first and then runs fine. I don't know if I have a condenser, it's electronic [point saver] type system? David Kirk system? Anyway, you make good sense when you state that I should check the electrical system. Probably start with the ground and work from there. There is a splice on the plug wire?????? Thanks for all the help!


Jim

I've known guys to splice hard core wire to fiber before..Daves advice..new hard core plug wire....Dave is familiar with Kirks" system,I am not....good luck

 

[kphill]

I think you are totally overthinking the problem.. It takes three things to make an engine run.. fuel,spark,and timing.. If you have fresh fuel, a good plug that works, and fires at the appropriate time it will run.. even with low compression these engines will run.. If you get it running and has no power or smokes like a chimney then think about looking into engine internals..

 

[gary noblit]

It is never my intent to tell someone what to do.It is make knowledge available to them so they can learn from the experience.Hence the whats,whys and detailed answers to questions ....The application of such answers is up to them...being analytical is a process.....

 

[dmerkle]

I think you are totally overthinking the problem.. It takes three things to make an engine run.. fuel,spark,and timing.. If you have fresh fuel, a good plug that works, and fires at the appropriate time it will run.. even with low compression these engines will run..

I was taught an engine needs air-fuel and spark.
Spark and timing are the same thing. Engine doesn't run very well on full choke. Engine needs air to run.

 

[kphill]

Spark and timing are not the same thing.. If the spark is too late it will do no good.. and an engine is nothing more than an air pump that is powered by fuel... these engines are very simple and they take very little to run..

 

[Jim Saunders]

Great help, tomorrow is another day and will try all the above. Will start with a new plug wire and go from there.


Jim

 

[kphill]

Jim, if you have a jumper wire, clamp it to the threaded part of the plug and ground it.. plug your wire on to the plug and crank it over and look for spark.. If you have a good spark you will not need a new plug wire..

 

[dschwandt]

He said the wire had a splice in it.
Problem waiting to happen IMHO.

 

[Jim Saunders]

He said the wire had a splice in it.
Problem waiting to happen IMHO.

Had a gas station make me up a plug wire. Will try it tomorrow. FYI, took the tape off the old wire...it was nasty. Thanks for all the help guys.


Jim

 

[dmerkle]

Spark and timing are not the same thing.. If the spark is too late it will do no good.. and an engine is nothing more than an air pump that is powered by fuel... these engines are very simple and they take very little to run..

What if you have too little or too much fuel going into the engine in question????? You will need 4 ( correction 5-air ) things to make an engine run with your way of thinking.

Again ignition is part of spark.

 

[kphill]

You will have fuel run out of the fuel bowl vent before you have that much run into the engine..

 

[dmerkle]

You will have fuel run out of the fuel bowl vent before you have that much run into the engine..

Let's turn the the high-low speed air-fuel screws in or out so the engine doesn't run right. Fuel won't come out of the fuel bowl vent if float is set right.
You will have to adjust the carb to get a good air-fuel mixture in the combustion chamber so the spark will ignite the air fuel mixture.

Again ignition is part of spark. The ignition system IH Cub Cadets have consist of the spark plug, spark plug wire, coil. points, condenser, battery/charging system.

 

[kphill]

Dale, I have been working on engines for 45 years.. I recently retired as an assembler of 4400 hp. Diesel locomotive engines.. I am trying to help this poor guy get his engine running not confuse him even more..

 

[tkhoffman]

I was taught an engine needs air-fuel and spark.
Spark and timing are the same thing. Engine doesn't run very well on full choke. Engine needs air to run.

Spark and timing are not really the same. If you have spark but it's at the wrong time... You are nowhere.

 

[kphill]

Tony, that is exactly right... If it fires with the valve open nothing is going to happen...Also dale you say nothing will come out of the fuel vent if the carb is adjusted properly.. There will if the float has a hole in it or if the needle valve is not seating.. Also the carb sets lower than the intake so fuel is not going to run into the cylinder ..

 

[JPrattico]

Attempt at a summary of what an engine needs to run:

-You need spark at the proper time, air, fuel, and compression for an engine to start.

-Proper air-fuel mixture is necessary for the engine to run properly. Adjust the main jet and air screw as needed. Main jet is adjusted at WOT and then air screw at idle. Be sure gas is decently fresh and the tank and lines are clean and clear of debris. Be sure carburetor is also clean of any debris. Air filter must be clean and allow proper air flow as well.

-Timing needs to be set right and points need to be clean and properly gapped in order to receive proper spark, as well as power from the battery, coil, and condenser. Coil and condenser must be in working order, as well as a charged battery.

-For good compression, valves must seat properly in the block, valve clearances must be set right, and piston/rings/bore must not be too worn out. Head gasket cannot be blown and head should be an almost perfectly flat surface. Spark plug threads in head cannot be rounded or stripped either.

-The crankcase is also important for an engine to run and stay running. Be sure it is filled with good, clean engine oil, free of any debris. Be sure oil dipstick stays closed and cannot pop open, and that the breather reed valve functions properly. Make sure breather filter element is not clogged up.

A lot of info above and it was kinda confusing to read through it all, hopefully I've summed everything up.

 

[dmerkle]

Tony, that is exactly right... If it fires with the valve open nothing is going to happen...Also dale you say nothing will come out of the fuel vent if the carb is adjusted properly.. There will if the float has a hole in it or if the needle valve is not seating.. Also the carb sets lower than the intake so fuel is not going to run into the cylinder ..

Hole in float goes under the heading of having the carb adjusted correctly.