Float Needle Sticking Closed

dbbyleo

Forum Newbie
Joined
May 23, 2011
Threads
1
Messages
4
I have a Briggs and Stratton Craftsman mower. I've had for over 8 years and finally had to do a Carb rebuild cause I found it to be all gummed up this season.

So I ordered the kit from Briggs... rebuild went well. After the rebuild, all ran well and was able to mow for over an hour without problems.

In the following week, I started having problems. The mower would run for about 3-5 minutes and then would stop.

I found the root cause - it appears the float/needle is getting stuck in the rised/closed position causing the bowl to run dry. The way I figured it out was by removing the air filter so I can see the jet in the intake. I let the mower run and can clearly see fuel come up through the jet. I can also press the primer bulb and see a surge of fuel come up. After running steady for about 3-5 minutes... the engine starts to hesistate and I can see fuel flow becoming more and more intermittent until the engine stops all together. If I hit the primer bulb immediately after no fuel comes up the jet.

I let it sit there for a few minutes, then I hit the primer bulb again and fuel comes up the jet again. I can only assume the needle/float finally drop again to let fuel fill the bowl.

Initially, I realized I was over tightening the bowl nut. As soon as I realized this, I loosen and re-tighen the nut just enough so the bowl is not leaking. This kinda fixed - I can keep the mower running for 10-15 minutes, but again would eventual stop.

During the rebuild, I did replace all the gaskets that was in the kit, including the little one for the needle. Im my haste, I may overlooked the gasket for the bowl nut (if there was on supplied). Could that gasket be the culprit causing me to tighten the bowl more than I need to and causing the float to may be not sit properly in the bowl?

If not... has anyone ever tried to put a small, light spring on the needle to keep open until the float rises?

Any thoughts?
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,865
You didn't happen to put the little rubber seat in upside down. I have also seen the rubber seat swell and stop the fuel flow. been having a problem with the seat tearing up on insertion on the latest kits that i have installed.
 

dbbyleo

Forum Newbie
Joined
May 23, 2011
Threads
1
Messages
4
That little gasket has two distinct sides. One side has a "small ring" and the other side is just flat. I've installed the gasket with the ring side facing away from me as I insert it into the hole.

I haven't tried reversing the gasket and see if that makes a difference. I also wish I paid attention to the orientation of the original gasket.

This is good and I'll give it a try, Now that I think about it... that ring may give the gasket enough play so that it doesn't "grab hold" of the needle when the needle plunges into the gasket.
 

jeff

Well-Known Member
Joined
May 8, 2010
Threads
8
Messages
151
You put it in right, the groove is suposed to be toward the carb body. However, did you seat the part firmly at the bottom of it's hole? If you did not, then that is likely the cause of your problem.
 

dbbyleo

Forum Newbie
Joined
May 23, 2011
Threads
1
Messages
4
Hmmm... now that you say that... I wasn't really sure how the gasket sat in the hole. I just lightly slid it down that hole, but didn't really apply any real pressure to make sure it "went all the way in".

I'll give that a try. Thanks!!!!
 

dbbyleo

Forum Newbie
Joined
May 23, 2011
Threads
1
Messages
4
Well... I'm happy to report my problem is fixed. Thanks Jeff! It was that little rubber gasket for the needle. I took an allen wrench just about the same size as the gasket and used that to gently nudge it further into place. And sure enough, when I reassembled the float and needle, I noticed right away that the float could rise a lot futher without the needle stopping.

Just mowed my 0.25 acre lawn today and the only time the mower stopped was when I needed to.

I've had this mower for over 8 years... and now with the gained carburator knowledge, it may indeed go another 8. Just think I almost threw in the towel and bought a new thinking I was justified. My next one would have been a Honda - a pretty penny that would have been. As nice as it would have been to have that... I'm much happier to know I'll continue to get my money's worth on this one.

Thanks again. Gotta love internet forums...
 
Joined
May 29, 2011
Threads
50
Messages
1,456
You didn't happen to put the little rubber seat in upside down. I have also seen the rubber seat swell and stop the fuel flow. been having a problem with the seat tearing up on insertion on the latest kits that i have installed.


Yep i know what you mean ILENGINE i have had this problem as well they are getting cheaper on the materials for the seats i guess..
 
Top