Cub 127 suddenly wont start ideas

[Cubstudent]

Hello members, Ran into an issue with my 127 . Its been strong and faithfull thru the winter hauling firewood trailer. Sat since needed in my garage. Went to start, cranks and puffs a bit but wont catch. Tried new plug, gas.ect. Only sat for 4 weeks. Oil is clean, finally took compression, 50 lbs max. Thought of a valve hanging open. Soaked entire too end in marvel. Let it sit for 1 week. Cleaned out the cylinder and took compression,same 50. Added oil into cylinder,went up to 90. I did get it to start on that with gas in the plug hole. Ran supper rough, coughing thru carb,flames, couldnt get it to stay running. Took compression again ,back to 50 lbs. Im looking at piston/rings but wanted to ask you guys if I might have something else going on that Im not aware of. Cam timing or flywheel timing,something that might have let go . I have owned and used this for 5 years and its been the most dependable of all my yard tools. Thanks for any help. Cubs for ever !!!!

 

[mgonitzke]

That sounds about normal since the engine has a compression release.

Engines need fuel, compression, and spark to run, and the spark has to occur at the right time. Make sure it has spark and is getting fuel past the carb.

 

[1811Cub]

Most common failure from sitting, even just for a few weeks is dirty points. Ensure they are clean, and use a points file to clean them up. Make sure the condenser is working, and that the points are opening and closing. Once it is running, ensure the gasket for the cover is sealing.

 

[Cubstudent]

Thanks for the ideas. I did check the points, they where in good shape, touched them up and opened up a tad. With key on and opening them by rotating engine have good spark at the plug outside of the motor. Cant be sure how condenser is but I would think I wouldnt have spark if it is bad. I wasnt aware this motor has compression release?? Im familar with alot of other mower engines that have a spring loaded device on the cam, could this engine have that also. Its a 1969 cub cadet 127 with a 12 HP kohler engine. That might be my issue if its like half in or out kinda. When I did get it started it was running terrible at only wide open,popping thru carb. Ill have to investigate the cam system and see if that could be my issue. I appreciate all your help and will get back to you about how things go. Thanks again

 

[mgonitzke]

The service manual for the engine is a free download from Kohler's website. I'd suggest downloading that and reading it since you aren't familiar with this engine.

Compression release is not likely the issue here. If it is popping through the carb, that would suggest the timing is advanced too far. Here is how to reset the timing to make sure that it is correct. http://mgonitzke.net/cubcadet/tools/static_timing.pdf

 

[Cubstudent]

Mgonitzke, That is awesome help that I wasnt aware of. I will be trying it as soon as I can, tomorrow if Im able but here in upstate NY hard rains forecasted so I may need to wait. Thanks so much for your help. Im not sure where that hole is ,how large it is, even with your great pic Im just not seeing it. No problem as It will make more sense when I get out on the motor. I will get back to you when I get into it. Thanks again.

 

[kphill]

I too would rule out the ACR... Take off the gas cap and smell the gas in the tank... Dead gas will do that too...Also try a new Autolite plug..

 

[eweiss]

Hello members, Ran into an issue with my 127 . Its been strong and faithfull thru the winter hauling firewood trailer. Sat since needed in my garage. Went to start, cranks and puffs a bit but wont catch. Tried new plug, gas.ect. Only sat for 4 weeks. Oil is clean, finally took compression, 50 lbs max. Thought of a valve hanging open. Soaked entire too end in marvel. Let it sit for 1 week. Cleaned out the cylinder and took compression,same 50. Added oil into cylinder,went up to 90. I did get it to start on that with gas in the plug hole. Ran supper rough, coughing thru carb,flames, couldnt get it to stay running. Took compression again ,back to 50 lbs. Im looking at piston/rings but wanted to ask you guys if I might have something else going on that Im not aware of. Cam timing or flywheel timing,something that might have let go . I have owned and used this for 5 years and its been the most dependable of all my yard tools. Thanks for any help. Cubs for ever !!!!

Those psi reading indicate that the rings probably are either glazed or stuck. May not have enough suction to pull fuel from a dirty carb is why oil and fuel directly will work. Try doing it several times after cleaning the carb

 

[1811Cub]

On a ACR engine, you will need to spin the engine backwards to defeat the ACR, and to obtain a remotely accurate number. This is not easy to do. A lot of recommendations are to do a leak down test instead.

 

[mgonitzke]

Those psi reading indicate that the rings probably are either glazed or stuck. May not have enough suction to pull fuel from a dirty carb is why oil and fuel directly will work. Try doing it several times after cleaning the carb

Those readings indicate the compression release is working properly. No information about the condition of the rings, etc. will be gleaned from doing a compression test spinning the engine in its normal direction of rotation.

 

[Cubstudent]

Hello all you guys. Thanks so much for your help and interest. I have learned so much about this engine just from you memeners attempting to help me. Well , Its all better now !!! When it failed to start I messed with the points. Eye balling and Im 61 so thats never good. Mgonitzke had sent me proper procedure to set timing and points. Thats what was my problem, I did it exactly that procedure and turned the key, fired right up. Dont know how to thank you all for the information as I know more about how this engine is designed. Thanks again

 

[1811Cub]

Another success story!

 

[Cubstudent]

Yep,but only due to the great forum members who got right to giving me information and suggestions. I truely didnt expect such timely responses, but appreciate everyone of them. Hope I might be able to help someone like that in the future. Thanks All !!!

 

[Cubstudent]

Quick video of the results of your help. Muffler was off at the time,took it off when I first soaked the cylinder with marvel, as I figured, a bunch ran out of the pipe and would have filled my muffler. Lol. Thanks guys