Can't keep engine running - need ideas!

[asbennett]

Hi all - I am new here and mostly to Go Karts. I have a 5HP Briggs & Stratton engine. The engine was locked up due to sitting out in the weather. I pulled the top and freed the piston up and cleaned the carb. Replaced the gas tank with a used tank of a similar engine. (tank had water and rust in it). The engine will start only if I put a little gas directly into the carb. Once it burns this off, it dies. I have checked the pick up tube and it is clean and clear of any debris. I don't know what else to check or test. Help please!

 

[Buick455]

did you buy a rebuild kit for the carb? if not, for a B&S its not that then much money. I would totaly rebuild the carb and go from there.

 

[dragracing1213]

Maybe your tank doesn't have enough pressure on it to get gas into the carb. You should check and make sure that the gas is flowing out of the tank. Take the tank off and take the gas line off of the carb. then let the gas go into a jar. If it gas goes through, your good. If it doesn't, rebuild the carb and get a new gas line.

 

[THE HUNTER]

is this the kind that has the tank mounted directly under the carb?
if it is, and the carb has two pickup tubes on the bottom of it..
then make sure the rubber diaphragms between the carb and tank are soft and flexible, if they arent, you need new ones.
the diaphragms act as a kind of fuel pump operated off the vacuum pulses from the intake stroke.
the long pipe pulls fuel from the tank, and puts it into a little bowl, which the small one pulls fuel out of which is then mixed with air, ect.

the old style Briggs with the tank under the carb would only have one tube, which draws fuel directly out of the tank, and into the carb. but you would have to adjust the carb with the tank half-full, and the fuel/air mix would change slightly with different fuel levels.
the two tube system just keeps the fuel at a constant level so the fuel/air mix stays the same at any fuel level in the tank.

so if the rubber diaphragm isnt flexible, in the two tube system, you wont be getting any fuel into the carb, even if the tubes are clear....


idk if that even applies to your situation..
but hopefully it helps someone lol

 

[ChadClancy]

Hunter,

I'm having a similar problem with my carb except that it just wants to run under full choke. Any time I cut back on the choke, it dies. I have the carb with the dual pickup tubes and the small cup tank in side the main tank. I took the carb off and found the small pickup tube to be gummed up quite a bit. I cleaned it out good as well as the cup which was all gummed up in the bottom. Now it looks nice and shiny. I also cleaned out the single fixed high-speed jet and replaced the diaphragm. It still doesn't want to run unless fully choked.

I was wondering if it could be a problem with the gasket between the tank and the carb. I have a full set ordered and that is what I was going to try next.

The other thing I was wondering about this carb is whether the governor is adjustable and if so, what is the procedure for adjusting it?

 

[THE HUNTER]

if it only runs with the choke on, that means the fuel/air mix is too lean to burn for some reason..
if all passages are clear, and all adjustable things are set to the starting point in your manual, and it still wont work. yeah, try the new carb kit, and see how that works.


as far as governors... officially, no, you should not try to adjust them in a way not described in the manuals, as it can be dangerous.....

that beings said.... yeah, you can. if its a wind-vain type, its pretty easy, just change the tension on the springs, also there are usually different places to put the linkages.
internal govs are a little harder, and ive never done it, so idk how well it would work, but i figure changing the weight of the fly-weights in the crank case would make a big difference in the governed speed, and some math would be needed to do it right the first time.
but for smaller adjustments, you wouldnt have to open the engine up. there is a way explained in the service manuals how to do it.


i think we are getting off topic with the governor stuff lol
searching for a thread, or posting a new one if you cant find one on what you are looking for is always best

 

[ChadClancy]

Thanks for the info.

For the high speed jet adjustment, what I've read is to back the screw off 1.5 turns from being fully closed. I've tried backing it off even more but that doesn't seem to help. I'm hoping that it's just sucking some air somewhere it shouldn't be. It may be that the governor is fine once I get this problem with the choke fixed.

 

[PitBoss]

One answer SEA FOAM!!!! and lots of it!
Do you have a picture of the carb/motor? It may help some of the peeps here. I was having issues with my honda gx160. Was getting gobs of fuel, but it would not stay running. I used about half a can of deep creep (sea foam in spray form) and after a couple of pulls it is running like a champ! I took apart the carb and hosed EVERYTHING out. I spent about 45 min working on this and it worked. I would also recommend the gasket kit as well. They are cheap and if it has been sitting out long enough where the motor was locked chances are the rest is toast (ummm warm buttery toast) too.

 

[ChadClancy]

The gasket kit seemed to do the trick. The old gasket between the carb and the tank was in really bad shape so it was probably sucking air somewhere. It now runs fine without being set to full choke.

I've used seafoam on my vehicles but never on a 4-cycle. I wonder if it would do some good just to add some to the gas.

 

[PitBoss]

You will be fine just add a smaller amount. On a two cycle you can still use it, but I would use the deep creep or put some sea foam into a spray bottle and introduce it into the intake.