MTD 1998 5/24 Power Loss - Solved - Snowblower Forum : Snow Blower Forums
 
LinkBack Thread Tools
post #1 of 9 Old 03-06-2013, 11:44 PM Thread Starter
Junior Member
 
Join Date: Feb 2013
Posts: 7
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
MTD 1998 5/24 Power Loss - Solved

My 1998 24" MTD 5 HP Tecumseh was down on power and would only run with partial choke. After checking the carb and finding no issues, I was at a loss of what was wrong. After looking at the re-powering threads by Bain and GustoGuy, I was seriously considering going down that path.

After a little more research, I decided to check the valve clearances. It turns out that the exhaust valve stem stretched enough to prevent the valve from closing. Apparently this is a common problem with these flat head engines.

After adjusting the valve clearance it is now running like new.

If your having issues with your flat head engine and have gone through carb, it might be worth checking your valve clearances.

Dave.
dlk4602 is offline  
Sponsored Links
Advertisement
 
post #2 of 9 Old 03-07-2013, 11:02 AM
Moderator
 
Join Date: Mar 2011
Location: Minnesota
Posts: 2,605
Post Thanks / Like
Thanks (Given): 4
Thanks (Received): 137
Likes (Given): 14
Likes (Received): 319
Good info, glad to hear you got it fixed.
HCBPH is offline  
post #3 of 9 Old 03-21-2013, 09:59 PM
Junior Member
 
Join Date: Mar 2013
Location: New Jersey
Posts: 27
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
Definitely good info. I read about this also. Did you notice any popping out the exhaust,low compression or other symptoms? Did you have to lap the seat due to burning or were you able to just set the clearance? I just picked up a 2005 Yardmachines/MTD 5.5 HP/24, I am in the process of checking it out. So far-so good, but I have not blown snow to really test it out with a load yet .

Last edited by Edge; 03-21-2013 at 10:04 PM.
Edge is offline  
post #4 of 9 Old 03-21-2013, 11:49 PM Thread Starter
Junior Member
 
Join Date: Feb 2013
Posts: 7
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
The main symptoms were loss of power, hard to start and only ran with the choke 1 click on. I did lap the valves although they really didn't look that bad. From what I have read, you really cannot get a good compression test because of the compression relief on these engines.

I also added a homemade impeller kit using 3-ply baler belt. This has made a significant improvement in performance. You may want to consider doing this to yours.
dlk4602 is offline  
post #5 of 9 Old 03-21-2013, 11:50 PM
Senior Member
 
Join Date: Nov 2012
Location: NH
Posts: 121
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 2
Likes (Given): 3
Likes (Received): 4
Quote:
Originally Posted by dlk4602 View Post
My 1998 24" MTD 5 HP Tecumseh was down on power and would only run with partial choke. After checking the carb and finding no issues, I was at a loss of what was wrong. After looking at the re-powering threads by Bain and GustoGuy, I was seriously considering going down that path.

After a little more research, I decided to check the valve clearances. It turns out that the exhaust valve stem stretched enough to prevent the valve from closing. Apparently this is a common problem with these flat head engines.

After adjusting the valve clearance it is now running like new.

If your having issues with your flat head engine and have gone through carb, it might be worth checking your valve clearances.

Dave.
Great tip. Thanks.
Pythons37 is offline  
post #6 of 9 Old 05-18-2013, 01:12 AM
Junior Member
 
Join Date: Mar 2013
Location: New Jersey
Posts: 27
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
Quote:
Originally Posted by dlk4602 View Post
..... From what I have read, you really cannot get a good compression test because of the compression relief on these engines.
..............

I was thinking a little more about the compression test. On a good engine there should be some amount of compression even with the compression release. A quick approximate test I found is there should be some resistance when you pull the recoil on the Tec. If not, you have low compression. But it is not very precise.

If you get a chance maybe you could do a compression test and we might have a known compression on a good 5 hp Tec engine for comparison. I am going to test my 5.5 hp Tec. It has a revised compression release compared to the 5 hp, so the number should be different.
Edge is offline  
post #7 of 9 Old 05-18-2013, 11:53 AM
Moderator
 
Shryp's Avatar
 
Join Date: Jan 2011
Location: Cleveland, OH
Posts: 4,159
Post Thanks / Like
Thanks (Given): 1
Thanks (Received): 196
Likes (Given): 6
Likes (Received): 250
I was under the impression that these engines will register around 60 PSI on a compression test with the release device on them. I haven't checked any myself, but that was the number I saw on some videos.
Shryp is offline  
post #8 of 9 Old 06-22-2013, 10:11 PM
Junior Member
 
Join Date: Mar 2013
Location: New Jersey
Posts: 27
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
Well, I got around to doing a compression test today - 75 psi dry and 87 psi wet at about 85 deg F. I didn't have a chance to warm it up to temp, so that probably accounts for the 16% diff between dry and wet. No rocking on the needle, so valves seem OK. Still, it looks pretty decent. I'll see if I can get a comp test at operating temp.
Edge is offline  
post #9 of 9 Old 06-27-2013, 09:13 PM
Junior Member
 
Join Date: Jan 2011
Posts: 6
Post Thanks / Like
Thanks (Given): 0
Thanks (Received): 0
Likes (Given): 0
Likes (Received): 0
May I ask what you used for valve clearance? My owner's manual on my Sears Craftman 5hp (Tecumseh HSSK50) flat head lists .010 in for both intake and exhaust. I have seen other listings for .008 intake and .010 exhaust. for that engine.
nelsontj 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