Nearly impossible to start, but runs fine. Coil? - Snowblower Forum : Snow Blower Forums
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 02-07-2015, 09:39 PM Thread Starter
Junior Member
 
Join Date: Feb 2015
Posts: 3
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
Nearly impossible to start, but runs fine. Coil?

I have a 15 year old Murray snow Thrower (model # 622505) with a Tecumseh HSSK50-67394S that I had professionally tuned up about 5 years ago. I’m very good about using Stabil in the gas, and at end of each season I drain the gas tank, drain the carburetor bowl, coat the cylinder with a teaspoon of oil, grease the zerks, and change the oil. And with a new plug put in each winter, it fires up reliably and easily on the first pull, as it did this winter. But after running fine earlier in the season, last week it just would not start (after a month of non-use, and my wife had put gas in the tank without Stabil). So I drained the tank and the carburetor bowl, filled with fresh gas from the pump (with Stabil and with one ounce per gallon of Seafoam) but it still wouldn’t start. Finally, after 10 minutes of heroic and exhausting trying, I got it started. And it ran fine – no sputtering, stalling, surging. I ran an entire tank of gas through without a problem, and figured we’d be all set. But after shutting it off, despite a warm engine that had just been running, it wouldn’t start again….at least it wouldn’t start without very heroic pulls multiple times (despite a very warm engine). After 10 minutes of trying to the point of near exhaustion, I got it started again. I confirmed this problem by again shutting it off, and having to work like a dog to get it started. Once started, it runs fine. I never had problems like this – even earlier this season it would always start on the first pull.

So I suspected a problem with the carburetor. I tried Mechanic in a Bottle and precisely followed the Youtube directions to the T. But after this overnight treatment it still wouldn’t start… Ten minutes of exhausting pulls later, I got get it started, and ran an entire tank of gas to better dilute/flush out the Mechanic in Bottle and get more Seafoam through the carburetor. But still, I again can just barely get it started. After pulling/pulling/pulling to start it, if I check the plug, it’s wet. (BTW, I already tried a new plug). I can see a spark when I ground the plug to the engine housing and pull the starter – but I can’t tell if the spark is appropriate “strength” or not. So on to the questions:

Is this more likely a carburetor problem, or an ignition problem? (Again, the engine runs fine once I can get it running, but it’s nearly impossible to get it running). I don’t think I trust myself to rebuild a carburetor….I’d have to take it in to the shop and fork over the big bucks they charge around here.

To test the coil, which ignition tester do you recommend I purchase (Will this inexpensive one from Amazon do the job of confirming the coil is fine as well as demonstrate that the coil is bad?)




I’d certainly feel comfortable changing the ignition coil (about $45 for the part) if that were proven to be the problem.

Thank you for your thoughts
Glove
Glove is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 02-07-2015, 09:57 PM
Senior Member
 
RoyP's Avatar
 
Join Date: Oct 2014
Location: Troy, New York
Posts: 374
Post Thanks / Like
Thanks (Given): 3
Thanks (Received): 9
Likes (Given): 7
Likes (Received): 4
I would say your problem is a dirty carburetor. I'm not a fan of doctor in a bottle. I recommend that you go to NAPA get a gallon can of carburetor cleaner....clean by soaking the complete carburetor with jets removed in the cleaner, include the jet needle valves. You can see a difference in the carb, I really think this will solve your troubles. Also check to see if your machine can accept a elec starter..
RoyP is offline  
post #3 of 17 Old 02-07-2015, 10:19 PM
Senior Member
 
db9938's Avatar
 
Join Date: Nov 2013
Location: SW Ohio
Posts: 3,188
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 143
Likes (Given): 0
Likes (Received): 297
I concur on the carburetor needing a cleaning.


Garage:
MTD....2 stage(modern 8.5 HP) not my favorite
Honda HS622 TA-B - acquired at an auction- nice machine for it's size.
Toro S-140- Picked it up on trash day... it runs, sort of.
Yamaha YS 240 TB "Ricky" latest Craigslist find- on the bench now.
db9938 is offline  
post #4 of 17 Old 02-07-2015, 10:22 PM
Senior Member
 
Normex's Avatar
 
Join Date: Feb 2014
Location: Near Ottawa Ont
Posts: 1,371
Post Thanks / Like
Thanks (Given): 52
Thanks (Received): 85
Likes (Given): 27
Likes (Received): 82
Quote:
Originally Posted by Glove View Post
I have a 15 year old Murray snow Thrower (model # 622505) with a Tecumseh HSSK50-67394S that I had professionally tuned up about 5 years ago.
To test the coil, which ignition tester do you recommend I purchase (Will this inexpensive one from Amazon do the job of confirming the coil is fine as well as demonstrate that the coil is bad?)

I’d certainly feel comfortable changing the ignition coil (about $45 for the part) if that were proven to be the problem.
You certainly have a handle to keep your Murray in shape, of course the first culprits as you correctly point out is gas and spark, I am inclined like you towards the spark and it would be fairly cheap to find out with this spark checker pointed out by members here, it will show you the spark quality being bright blue which is indicative of a good coil but you may have to test it also when you have a hard start situation.
Here's the part:



After testing and if your coil seems in good condition, I would definitively check the valves. Intake should be .008 and exhaust at .012

Check the vid of Donyboy explaining how:

Good Luck and let us know how it turns out.

Snow Removal Apparatus I own:
Ariens ST1530DLE, and good ole arm powered scrapper.
The 15 HP is a new Ducar engine sold
by Princess Auto in Canada.
Normex is offline  
post #5 of 17 Old 02-08-2015, 08:07 AM
Senior Member
 
CarlB's Avatar
 
Join Date: Jan 2011
Location: Southern New Jersey
Posts: 753
Post Thanks / Like
Thanks (Given): 3
Thanks (Received): 35
Likes (Given): 4
Likes (Received): 81
another thing to check is to make sure the primer is working. It doesn't sound like your problem here but it could be. Sometimes the hose that goes to the engine get a hole rubbed in it and it causes the primer not to work.
CarlB is offline  
post #6 of 17 Old 02-08-2015, 09:08 AM
AL-
Senior Member
 
AL-'s Avatar
 
Join Date: Oct 2014
Location: Vermont/Quebec border
Posts: 349
Post Thanks / Like
Thanks (Given): 7
Thanks (Received): 10
Likes (Given): 4
Likes (Received): 29
maybe take spark plug out and dry well , squirt a small amount of gas down plug hole, put plug back. Then see if it will fire up with just 3 or 4 pulls. If it does your ignition might be Ok. With my 4HP Briggs and Stratton I can take the shroud with pull assembly off with 3 bolts and with some fine 400 grit sand paper clean rust off flywheel magnet and end of coil where the gap is quite easily without disturbing coil.
AL- is offline  
post #7 of 17 Old 02-08-2015, 09:58 AM
Senior Member
 
Join Date: Dec 2013
Location: Massachusetts and Maine
Posts: 792
Post Thanks / Like
Thanks (Given): 3
Thanks (Received): 27
Likes (Given): 0
Likes (Received): 42
Hi Glove,
Welcome to the Forum.
Coil problems do not improve with exhaustive attempts to start. A dirty or partially blocked carb instantly alters your air/fuel mix causing hard start/restart issues. MH

1960 Ariens 45-10M
1961 Ariens 10M55
1977 Ariens 22000
1972 Ariens 10000
1990 Ariens ST724
1987 Toro 724
Murray Ultra 522
MTD Single stage
8 hp MTD hybrid plow
motorhead64 is offline  
post #8 of 17 Old 02-08-2015, 12:00 PM Thread Starter
Junior Member
 
Join Date: Feb 2015
Posts: 3
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
Thanks everyone for your interest, time and help. One other comment to make is that I have noticed something during my heroic tries to start the engine - the engine doesn't backfire or sputter when I pull the starter, but I notice that on some pulls of the same amount of force turns over the cylinder 6 to 8 times -- almost like I had pulled harder. I suspect "tiny explosions" in the cylinder (not really audible) are helping push the cylinder. During those times I feel that only if I had an electric starter to deploy for longer, it would have started. But it seems that in thinking spark versus fuel/air as me problem, there is no reason to think that the spark would be "stronger" once the engine is running. Presumably there is no ignition coil problem or magnet problem that would provide insufficient spark in my pulls, but provide sufficient spark once up and running. I'm telling you, once it starts, it performs like a champ...no sputtering under load, etc.

Based on the comments from everyone, I've done the following:
Rechecked the priming bulb - it squirts gas very well into the carburetor
Drained the gas (yet again) and used a 1/2" wrench to remove the screw/jet holding the bulb in place. The bowl had no varnish, and the screw/jets were completely clean - no gunk whatsoever. Could easily see day light through the larger hole. Used a tiny wire and carb cleaner to ensure that all passages are clear. The rim of the bowl and the bowl gasket had a smidge of gunk....carefully cleaned this with carb cleaner. Perhaps the "deeper workings" of the carburetor are still gummed up because mechanic in bottle easily reaches the bowl and screw/jet but not deeper. And hard to believe that just some minor bowl rim gunk would create an air leak in a way that that would make it impossible to start, but once started, run flawlessly.

So based on everyone's comments, I plan to do the following:
I will not empirically purchase an ignition coil although I will order the ignition tester anyway.
I will assume a carburetor problem and take off the carburetor and carefully dismantle/clean myself, or alternatively take to the local shop where I would have to wait a week or two, and pay with one of my extremities.
If after this it STILL doesn't start, then I'm at a loss - I won't be sure if I screwed up the carburetor settings/reassembly, or rather, assumed that this is some crazy electrical problem with ignition coil, magnets, grounding. At any rate, I'll keep y posted.

Again, thanks for everyone's help and interest.
Glove
Glove is offline  
post #9 of 17 Old 02-08-2015, 12:40 PM
Senior Member
 
Join Date: Dec 2013
Location: Massachusetts and Maine
Posts: 792
Post Thanks / Like
Thanks (Given): 3
Thanks (Received): 27
Likes (Given): 0
Likes (Received): 42
Glove,
When you hear little "pops" that sound like she wants to start, reduce choke by a click and continue starting. I think she will fire. MH

1960 Ariens 45-10M
1961 Ariens 10M55
1977 Ariens 22000
1972 Ariens 10000
1990 Ariens ST724
1987 Toro 724
Murray Ultra 522
MTD Single stage
8 hp MTD hybrid plow
motorhead64 is offline  
post #10 of 17 Old 02-08-2015, 03:25 PM
Senior Member
 
db9938's Avatar
 
Join Date: Nov 2013
Location: SW Ohio
Posts: 3,188
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 143
Likes (Given): 0
Likes (Received): 297
I would also check to see if the plug is wet, at the point when you hear the sputters of life. If it is wet, then it is not the carb. That would most likely rule that out, and would certainly make me lean towards spark and your coil.

Other thoughts, and not what I would normally recommend, but if you consider just the diagnostic fees of you local shop, you could go ahead and purchase the coil. Even if it ends up being the carb, you can buy those pre-set, online. Just bolt, connect and go.

Garage:
MTD....2 stage(modern 8.5 HP) not my favorite
Honda HS622 TA-B - acquired at an auction- nice machine for it's size.
Toro S-140- Picked it up on trash day... it runs, sort of.
Yamaha YS 240 TB "Ricky" latest Craigslist find- on the bench now.
db9938 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Snowblower Forum : Snow Blower Forums 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










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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