New Craftsman 247.889720 Throttle control not working - Snowblower Forum : Snow Blower Forums
 
LinkBack Thread Tools
post #1 of 3 Old 02-13-2019, 12:09 PM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 19
Post Thanks / Like
Thanks (Given): 7
Thanks (Received): 0
Likes (Given): 13
Likes (Received): 2
New Craftsman 247.889720 Throttle control not working

Hi, I helped a neighbor out with their barely used Craftsman 247.889720 snowblower. They had it sitting for 16 months and it would not turn over.

I took off the carb and cleaned - the varnish inside was worse than I could imagine (I have a Craftsman 5/22 from the 80s that looked better!). There was varnish in the bowl, and through all the tiny jets inside.

I sprayed Deep Creep (all I had on hand for "carb cleaner") and used a small needle and cleared all the jets I could find. I was able to get it running and it seemed to work great.

After longer use I've noticed the idle seems way high and the throttle lever doesn't affect the idle speed through the range at all - just Off in the off position or high idle in any other position. When we both used it yesterday after a storm we both experienced afterfire when moving the lever to Off when done using the snowblower.

I also noticed that the choke control seems to work strangely: when the engine is cold, you put it on choke in order to get it to turn over. Then after a few seconds, put it in the next position, and the RPMS go up, then the 3rd position it goes up even more, then in the last position the RPMS drop a bit. Once the engine is warm, if I try any of the positions other than WOT, the engine sounds like it's going to stall within seconds.

I don't know this engine/carb well - but I'm pretty sure I put it all together right with throttle linkages and choke control.

A couple things I could think of:
  • There was a plastic throttle stop screw in the carb I took out and when screwed it back in, I followed the directions here (last part of Step 5): https://www.searspartsdirect.com/rep...nowblower.html
  • The throttle spring is really delicate - could I have stretched it out too much on removal/reinstall?
  • The paper gasket on the carb got soaked in gas - is this an issue?

I appreciate any help/advice in advance!
Rob Chang is offline  
Sponsored Links
Advertisement
 
post #2 of 3 Old 02-22-2019, 06:38 AM
Senior Member
 
Join Date: Mar 2014
Location: Lowell area, MA
Posts: 3,217
Post Thanks / Like
Thanks (Given): 118
Thanks (Received): 272
Likes (Given): 355
Likes (Received): 621
Quote:
Originally Posted by Rob Chang View Post
After longer use I've noticed the idle seems way high and the throttle lever doesn't affect the idle speed through the range at all - just Off in the off position or high idle in any other position. When we both used it yesterday after a storm we both experienced afterfire when moving the lever to Off when done using the snowblower.
So the throttle lever moves, but basically changes between two speeds? Just idle, and full-RPM? That sounds like a possible issue with the governor, and its linkages/spring.

Quote:

I also noticed that the choke control seems to work strangely: when the engine is cold, you put it on choke in order to get it to turn over. Then after a few seconds, put it in the next position, and the RPMS go up, then the 3rd position it goes up even more, then in the last position the RPMS drop a bit. Once the engine is warm, if I try any of the positions other than WOT, the engine sounds like it's going to stall within seconds.

You were talking about the choke, but then mentioned WOT. Are you referring to a choke position? Or do you mean that, once the engine warms up, it will only run at full-RPM, regardless of the choke setting?

Quote:

I don't know this engine/carb well - but I'm pretty sure I put it all together right with throttle linkages and choke control.

A couple things I could think of:
  • There was a plastic throttle stop screw in the carb I took out and when screwed it back in, I followed the directions here (last part of Step 5): https://www.searspartsdirect.com/rep...nowblower.html
  • The throttle spring is really delicate - could I have stretched it out too much on removal/reinstall?
  • The paper gasket on the carb got soaked in gas - is this an issue?
Try adjusting the idle stop screw if you want. It shouldn't really hurt anything. That should control how far the throttle plate can close, which sets your low-RPM speed.

Hopefully that spring is fairly accommodating, and can handle some stretching. But I don't have experience with this engine/carb.

I doubt that would be an issue. If you want to check for air leaks at gaskets, start the engine. Now spray carb cleaner, or something similar (a flammable spray) around where the carb mounts to the engine. Spray it on the gasket, etc. If you have an air leak, the engine sound will change as you spray, due to the spray being drawn in at a gasket. You can also try spraying at the top of the throttle plate shaft, where it goes into the carb. Sometimes you can have an air leak there as well.

Ariens 1024 Pro
Toro Power Clear 221QR
Toro Power Curve 1800
RedOctobyr is online now  
post #3 of 3 Old 03-04-2019, 12:47 PM Thread Starter
Junior Member
 
Join Date: Nov 2018
Posts: 19
Post Thanks / Like
Thanks (Given): 7
Thanks (Received): 0
Likes (Given): 13
Likes (Received): 2
Thanks for the response, sorry for the delay in getting back to you:

So the throttle lever moves, but basically changes between two speeds? Just idle, and full-RPM? That sounds like a possible issue with the governor, and its linkages/spring.

>> Actually only one speed - it's either off, when the lever is fully to the right, or "on" at full-RPM anywhere else in the range.


You were talking about the choke, but then mentioned WOT. Are you referring to a choke position? Or do you mean that, once the engine warms up, it will only run at full-RPM, regardless of the choke setting?

>> I think I used the wrong terminology. When I say WOT, I meant the choke position that is furthest from the choke fully engaged side. My understanding is that put it on full choke to start it, then as it warms up, click the choke over one notch to keep it from stalling until you can move the knob all they way to the other side (4th position). I would have thought the RPMs would keep climbing as you click the choke over as it warms up, but that it was strange that it drops from position 3 to 4. It made me wonder if the butterfly was in the wrong position when I put the carb back on to the connecting arm...


Try adjusting the idle stop screw if you want. It shouldn't really hurt anything. That should control how far the throttle plate can close, which sets your low-RPM speed.

>>I will take a look a look at this too when I get the machine in my hands again.

Hopefully that spring is fairly accommodating, and can handle some stretching. But I don't have experience with this engine/carb.

>> I would hope so, thanks for the vote of confidence.


I doubt that would be an issue. If you want to check for air leaks at gaskets, start the engine. Now spray carb cleaner, or something similar (a flammable spray) around where the carb mounts to the engine. Spray it on the gasket, etc. If you have an air leak, the engine sound will change as you spray, due to the spray being drawn in at a gasket. You can also try spraying at the top of the throttle plate shaft, where it goes into the carb. Sometimes you can have an air leak there as well.


>> Great idea, I would hope this isn't it either!.
Rob Chang 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



Similar Threads
Thread Thread Starter Forum Replies Last Post
Running air-cooled gas engines at full throttle. sscotsman Snowblower Repairs and Maintenance Forum 78 04-30-2019 05:06 PM
Ariens Platinum 24 SHO Model 921050 Throttle Control Issue derill03420 Snowblower Repairs and Maintenance Forum 2 12-21-2018 03:53 PM
HS1132 no throttle response oljm Honda Snowblowers 14 11-22-2016 03:06 PM
Ariens belt and throttle control question rufushusky Snowblower Repairs and Maintenance Forum 7 03-30-2015 07:07 PM
Craftsman Tecumseh 7hp throttle linkage help needed markdmz Craftsman Snowblowers 2 03-02-2015 08:32 PM

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