Help with Walbro LMT carb


Old 02-17-07, 02:37 PM
Thread Starter
Join Date: Feb 2007
Posts: 1
Help with Walbro LMT carb

Hi guys,
I have a relatively new 5500W generator that I regularly start up every couple of months and keep Stabil in the gas. The last time I started it the idle would not hold when the choke was turned off. Turn it back on quick enough and the generator would catch back up and actually run too smooth for the choke being on. So, I guess some port is clogged in the carb. I took it appart and was amazed at the crud in the bowl. I am not so sold on Stabil at this time. Anyway, everything cleaned up relatively well but I have one question. There are two cast tubes that run down along side the main jet. They are blocked and I suspect that they should be. Anyone with this level of knowledge? I can usually clear tubes and vents like this but I can't figure out their other ends.
Any help would be appreciated.
Sponsored Links
Old 02-17-07, 04:22 PM
Join Date: Jan 2007
Location: London
Posts: 105
I have no idea what engine we're talking about here as different engines use different carbs, etc. but it is quite possible those small tubes could be bowl vents, idle ports, etc. There may also be a check valve in the tube(s) to prevent backflow, etc. and you would not necessarily be able to blow them out. If fact, it is possible to do irrepairable damage to the checkvalve if poking, pushing, prodding, etc. too vigorously.
Old 02-18-07, 11:38 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,779
In years past I used Stabil with mixed results. I continued to have gummed up carbs in certain engines and it made my boat seem to run a bit rough (and it don't like the smell). I think the root problem is that automotive gas has a shelf life and the varnishes and other crud will form sooner or later.

I have not had a single problem since I have been puting avgas (100LL) in my small engines near the end of their season. Even a blend of it with regular gas seems to do wonders. It's available at airports and I have never had it go bad. 100LL avgas contains lead so I would not run it all the time (it may foul your sparkplug after longterm use), and NEVER put it in your car or anything with emissions sensors or a cat. converter.

Back to your clogged carb. Try soaking the carb in some cleaner for a couple days. After soaking you can use a can of spray carb cleaner to spray up into the passages to try and clear them. The varnish deposits can get quite hard and a nice long soak is the best think I have found to dissolve them.

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 Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes