Tecumseh 22hp One cylinder intermittently - Page 2 - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information
Small Engines and Repair

Midwest Mower Pro

Reply
 
LinkBack Thread Tools Display Modes
post #16 of 34 Old 07-13-2019, 11:10 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

It appears on first test that carb work has improved my running.
38racing is online now  
Sponsored Links
Advertisement
 
post #17 of 34 Old 07-14-2019, 11:49 AM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

OK, thank you 38Racine! you have confirmed everything I'm seeing, re the two green kill wires going into the sleeve and coming out as only one green wire, and that each has a diode more or less hidden by the sleeve!

At this point I have replaced the coil on the weak cylinder, thought I was home free - not so. Not sure I set the gap exactly right: used a standard flat feeler guage and combined the .0120 and the .004 to get the .0124, placed it in the center of the coil between it and the magnet. It does run, but the intermittent issue is still there and now there's an occasional backfire, which I attribute probably to me not getting the air gap measured just right and so affecting the timing on that cylinder - not sure - maybe I should have measured the air gap on the outside ends of the coil instead of the middle. ??

Intermittent still, even with the green leads disconnected from the coil and taped off.

So, I removed the front cover from the carbs, checked the fuel flow to that cylinder - seems to flow ok, no obstructions, no obstructions visible from the inlet fitting.

I removed the bowl cover - looked ok, and I put it back on.

Since it still runs intermittently even with the green leads off the coil I'm thinking it has to be an intake system problem. I'm especially suspicious of those electrical devices - I think you or someone called them "anti-backfire solenoids": I know nothing about these things so I don't know how to troubleshoot them, and apparently you have to totally remove the carb to get to it.

Was it you who mentioned removing them and replacing them with bolts: do you think that would help in this case? And, what do you do with those electrical leads?

One observation I've had is that even with the green wires disconnected from the coil, and while its running, turning off the key does in fact kill the engine! Is this because those electrical things are killing the fuel flow? If so, and if one of them is defective could it be causing that cylinder to fire intermittently?

I'm attaching a video so you can hear and see - the weak cylinder is on the r/h side in the video, (l/h side from the seat looking forward).
So, here's how it sounds. I'm thinking fuel flow. both kill wires are disconnected and taped off.
Maybe those electrical things on the carbs?
Note the surging as it runs at a high idle.

I don't think fuel pump as that would affect both cylinders.

OK - I can't seem to add the video since it's an MP4 taken on my Android Samsung Galaxy Note9 and it's too big even converted to a .zip - So I've copied in the file/link name below but I doubt that it will work for you.

20190713_162706_512163665688869.mp4

I have been able to email this file to myself, so I know it can be emailed. It's 17mb btw.

Thanks again for your time and advice, let me know how it's going with your machine!

Last edited by mikeshoop; 07-14-2019 at 11:51 AM. Reason: add emphasis
mikeshoop is offline  
post #18 of 34 Old 07-14-2019, 10:08 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

Yes. When you turn key off power to the carb solenoids with stop the fuel going into main jet and engine stops. I just taped the solenoid hot red leads and left hanging. You might try a 50-50 mix of seafoam in the tank. Run for short runs. May miss a bit and smoke. Let sit and then repeat a bunch of times. That might clean any small blockage in the carbs.
38racing is online now  
Sponsored Links
Advertisement
 
post #19 of 34 Old 07-15-2019, 09:50 AM
3K Poster!!!!
 
Join Date: Nov 2009
Location: georgia's toe-nails of the foot hills
Posts: 4,651
Re: Tecumseh 22hp One cylinder intermittently

If you don't mind the mess, you can remove the ABF solenoids, and check them with a 9V transistor radio battery. When power is applied, installed or not, you should hear the solenoid click as it withdraws the jet blocker. It should also click when power is removed as the spring pushes the pintle back into place to block the main jet feed. You should be able to feel/hear the click as you move the ignition switch from OFF to ON.
tom

simplificate & add lightness

It's not how hard you work, it's how much you get done.
tomw0 is offline  
post #20 of 34 Old 07-15-2019, 04:12 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

Might need to pull the carbs to remove the abs as they are on the engine side sideways into the carb bowl. Not below the bowl like briggs.
38racing is online now  
post #21 of 34 Old 07-15-2019, 06:59 PM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

Thanks again, pulling the weak side carb tonight so I can get at it, I'll let you know what I find, planning on removing the abs altogether.
mikeshoop is offline  
post #22 of 34 Old 07-15-2019, 07:00 PM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

Thanks, I'll have it apart in a little while, hoping to get to a conclusion on this one. Many thanks for your help!
mikeshoop is offline  
post #23 of 34 Old 07-16-2019, 10:12 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

Well I put all the covers back on and actually was cutting grass. Ran about 20 minutes and was just finishing around trees of side yard when I lost power.I was hoping it was fuel because I'm running a small temporary tank. Not so. It was running but my temperature gauge on the exhaust indicated the left cylinder was again dead. I have a fuel filter so it shouldn't be a plugged carb jet. After stopping it I could not get restarted. Had spark. Pulled valve cover on right. Good valve movement and clearance. Did compression. 110 on left and now only 70 on the right. Think I'm going to throw a different engine on to test the mower. With the tecumseh on a bench I guess I'll pull the right head at some point.
38racing is online now  
post #24 of 34 Old 07-16-2019, 11:15 PM
MTF Junior Poster
 
Join Date: Dec 2018
Posts: 19
Id get a pair of inline spark testers and hook them up to see if one coil is cutting out on you. If it is i would inspect the ground wire leading to it and insure its not bare, hitting metal accasionally, and grounding the coil. If not replace the coil.

If spark is not the issue i believe those are twin carbed (a bit overkill if you ask me) once again inspect the wires for the fuel solenoids (anti backfire) be sure they are not bare. If you want to disable them just pull them out and cut the plungers off flush. They will become fancy looking bolts after that. If that does not fix the problem i would clean the carbs or replace them.
Bigskyguy is offline  
post #25 of 34 Old 07-17-2019, 08:40 AM
3K Poster!!!!
 
Join Date: Nov 2009
Location: georgia's toe-nails of the foot hills
Posts: 4,651
Re: Tecumseh 22hp One cylinder intermittently

38... If it ran well for those 20 minutes, and then power fell off, I'd suspect something making one of the valves fail to seat properly. Could be a sticky guide, closed up due to heat, something on the seat, gummy rockers, etc., or something simple or not.
I guess it could even be a head gasket that was/is on the verge, and 20 minutes of work was more than it wanted to do right now. Perhaps check cold compression to see if things closed up with the reduction in temperature?
tom

simplificate & add lightness

It's not how hard you work, it's how much you get done.
tomw0 is offline  
post #26 of 34 Old 07-17-2019, 10:44 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

Quote:
Originally Posted by tomw0 View Post
38... If it ran well for those 20 minutes, and then power fell off, I'd suspect something making one of the valves fail to seat properly. Could be a sticky guide, closed up due to heat, something on the seat, gummy rockers, etc., or something simple or not.
I guess it could even be a head gasket that was/is on the verge, and 20 minutes of work was more than it wanted to do right now. Perhaps check cold compression to see if things closed up with the reduction in temperature?
tom
In hindsight I should have retorqued the head bolts. I don't recall doing that. Certainly not the one that's under the pushrod guide. They were pretty easy to loosen. It is a blown head gasket.
38racing is online now  
post #27 of 34 Old 07-23-2019, 06:09 PM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

UPDATE! OK, so I removed the weak cylinder carburetor, disassembled the float assembly and blew out the fuel inlet with compressed air, no obstruction present - at least none that I could see, might be on the ceiling at this time - if there actually was one. None the less, no obstruction now.

I removed the anti-backfire solenoid and tested it with a 12v trickle charger: it seemed to work perfectly, but that is when provided a solid and consistent 12 v dc source. I don't know that the tractor is providing a constant 12v feed so I think I will replace the abs solenoid with suitable bolts just to take that out of the equation - I'll get the bolts tomorrow and probably do both carbs.

Then I'll reassemble and test.

One thing I'm not sure of: when I installed the new coil on the weak cylinder I used feeler gages to set the air gap measuring from the center of the coil to the magnet. Is the center the place to take the measure or should it be measures at the outer sides of the coil assemble (between the outer sides and the magnet. ??
mikeshoop is offline  
post #28 of 34 Old 07-23-2019, 06:24 PM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

YEEESSSSSSS!!!! It runs again, and better than ever.!! Apparently there was a problem with the weak side carburetor - never did find any trash or debris but after reassembling with new o-rings on the venturi inlet tubes (see below) it starting running great. I left the anti-backfire solenoids in place as they tested good. And I did replace one coil but I don't believe that had anything to do with the problem.

It was not uneventful though as in my exploratory efforts I somehow lost the little springs that go under the venturi fuel inlet tubes, and worse, didn't realize they were missing!! I put it all back together more than once and it wouldn't run at all. Finally after studying the parts diagrams I realized that the carb in the diagram had springs and mine didn't. So, after looking all over the garage floor I found one, but couldn't find the other one. I looked at Jack's Small Engine's diagrams and found the springs and some o-rings I thought would be a good idea and ordered them and they'll be here Wednesday - in the meantime, using my one spring as an example, and one of my o-rings, I found springs (too long) at Ace hardware, and O-rings in the plumbing section of Lowes. I trimmed the spring down to the right lenght and replaced my o-rings with those from Lowes and now it runs GREAT, more power than ever! So when the new parts come in I'll either put them on, now that I know more about what I'm doing, or possibly save them for later. I also got an extra coil - I'm convinced the original coil was not the problem so I'm keeping one old one and one new one on hand as spares.


Thanks to everyone for your input, I've learned a lot, and at this point I'm feeling like something of an expert on taking this tractor apart and putting it back together again!! I've replaced all the belts, the transaxle input shaft gears, and now the coils and carburetors!! Again, thanks to all of you for your help!!
mikeshoop is offline  
post #29 of 34 Old 07-23-2019, 11:25 PM
3K Poster!!!!
 
Join Date: May 2009
Location: ontario
Posts: 3,654
Re: Tecumseh 22hp One cylinder intermittently

When I was doing my carbs I knew about the springs but I had not pulledd the nozzle from carb. It was sitting in container. I thought that a bug had whizzed past me but it was the nozzle and spring launching. I immediately found nozzle on floor but like you I had to use a substitute spring. Week or so later I actually found the spring.
I'm just finishing up the heads. I decided to lap the valves. Now I'm looking for the assembly grease that I bought last January.
38racing is online now  
post #30 of 34 Old 07-25-2019, 01:15 PM Thread Starter
MTF Junior Poster
 
Join Date: Jul 2017
Posts: 14
Re: Tecumseh 22hp One cylinder intermittently

"lap the valves" : is this just a reconditioning of the valve seats? or is it a performance enhancement?
mikeshoop is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome