79 140 backfires-its the carbs but why?

[walleyehed]

Re: 79 140 backfires-its the carbs but why?

Remember what I said about disconnecting the cable and checking that all plates were completely closed?????

 

[mnw001]

Re: 79 140 backfires-its the carbs but why?

Well Kenny you did say that and the cables and linkage were all disconnected and the plate was closed on its own but I have to hold it closed appartlenty even though it looked like it was closed but yes you did call it..

 

[walleyehed]

Re: 79 140 backfires-its the carbs but why?

Just funnin' with ya... <br />You did a GREAT job of catching it, so give yourself some credit...some people would have given up..<br />Good job!

 

[mnw001]

Re: 79 140 backfires-its the carbs but why?

Well Thanks Kenny it has been an ordeal but I guess I love a mystery(not really)<br />Anyway I removed the oring seals and ran the motor again last night just confirm what I thought was going on. This is the problem the plates on the lower carb just will not stay closed without help. I worked on the linkage for about 2 hours and almost had it but not quite. I took another 1/2 wrap on the return springs and I thought I had it but not even that helped. Then I tried an auxillary return spring on the bottom carb and that fixed the idle but it put too much pressure on the linkage and I could not get them to open togeather.. So I think I need new carbs or humm I wonder if a machine shop could install a brass bushing if I removed the shaft. Might be more trouble than its worth. I think I rather newer carbs with primers anyway.<br />The bushing might be a thought since these babies seem to be trash anyway..I know I'd need new plate screws as you mentioned Kenny

 

[jy118lfd]

Re: 79 140 backfires-its the carbs but why?

Fish a 235 I had, had a bent throttle shaft and the port bore was closed but the starboard bore was open just a tad. I tossed the carb, too much to fix when carbs are a dime a dozen on e-bay. I will look for the 140 carbs I have. Never got to look due to snow. I am off Friday and will e-mail you.

 

[walleyehed]

Re: 79 140 backfires-its the carbs but why?

If you want to play, we've taken valve guide bushings for a 3HP Briggs & Stratton, re-bored and pressed these in, then took a reemer and worked it to the size needed.<br />I've even used the same screws if the heads are ok, just install them with the permanent-type Loc-Tite.<br />There may be an issue with the shaft itself though, and here's why...as atmospheric dirt comes through the shaft/carb body area, the grit embeds in the softer aluminum of the body and then "Eats" the harder shaft material..this is what causes the initial slack, then vibration allows (causes) movement of the shaft, wallowing out the aluminum body, so the shaft itself may have enough wear that it won't allow rebushing (putting George W. back in office).

 

[mnw001]

Re: 79 140 backfires-its the carbs but why?

Hey Jon <br />Just wondering if you had any luck looking for those carbs<br />Thx mnw001@hotmail.com