Small Engine Only Starts with Spray in Carb?

[ForestCoCabin]

I have small engine that only starts with starter fluid in the carb...
after that it runs just fine. Its a newer 5HP Briggs on an old Monkey
Wards minibike. How can I fix it ?

Thanks

[Ray]

if it need that extra low flash point for the engine to start, it could be several things, especially if its a newer engine. I believe I'd check the spark plug gap and clean it or just get a new one as cheap as they are. You can always take a look at the spark in a dark area, like close the doors on the shop with lights out and make sure its a good hot blue spark that will ignite easily. you only have, spark, air, and gas. so if the spark is hot enough then move on. A spark that is not hot enough to ignite light gas, might easily ignite ether to get it going but this isnt really good for the engine to use ether alot, it has no lubrication properties and will dry out the rings eventually could cause scaring on the cyl. walls they say. best wishes, ray

[agmantoo]

Spritzer a little gas instead of the ether and see if it will start. I think it will. If it does then the gas supply to the carb could be restricted and while hand cranking you are not getting enough vacuum to pull the gas into the engine. There could be a number of causes. The gas cap could have the vent in it nearly clogged, a supply gas line could be letting air in through a crack, the rings could be bad or stuck in the engine, etc. I would just give it the assist it needs to crank the engine and run a few tanks of gas through and see it the problem self corrects.

[d.dumont]

check the gas cap & fuel line, as mentioned... if they are good pull the carb apart & clean it... clean out any holes in it.. I usually use wd40 just to blow them out. Use a tooth pick to clean any holes that are (or might be) clogged, make sure float, needle & seat are functioning properly, put er back together & give it a whirl...


Dan

[foxtrapper]

There's a problem with your cold start circuit. Those engines typically use a butterfly choke. Either you're not actuating it manually, likely due to mal adjusted throttle linkage, or it's not actuating automatically. The automatic ones frequently don't work right because of dirt in their linkage and spring.

[Wis Bang 2]

Either a choke malfunction or the carb is sucking in air somewhere, check that the screws holding the carb to the engine & any screws holding parts of the carb together are tight.

[ponyboy123]

Is there a choke or a primer bulb?

[HermitJohn]

Originally Posted by foxtrapper

There's a problem with your cold start circuit. Those engines typically use a butterfly choke. Either you're not actuating it manually, likely due to mal adjusted throttle linkage, or it's not actuating automatically. The automatic ones frequently don't work right because of dirt in their linkage and spring.

The BS setup where choke butterfly closure is dependent on throttle setting will drive you crazy. On the Briggs on my old mower, I finally separated the choke from throttle linkage, added a homemade lever to choke shaft and a piece of baling wire as a control to the lever. Works ever so much better. Doesnt try to close the choke at highest governed throttle speed. Not sure why all the incredible goofiness over chokes on modern small engines. I mean it cant be just EPA as the Honda engines still come with a manual choke lever and work very nice, just like the old American small engines did. But the Americans now want to play games with partially disabled chokes that have big hole in middle of the butterfly, and plastic bubble primers, and lot unnecessary linkage carp that is just frustrating.

[foxtrapper]

Small engine makers many decades ago decided to integrate the choke with the throttle lever, reducing the levers to one. And I agree, it frequently does not work well.

Surprisingly, B&S did get it right on one new engine. Very right. Forget when series it is, but it's got an old fashioned spring loaded, vane opened choke. When the engine is off, the choke is closed. As soon as the engine starts to run, the air spun from the flywheel fan blows the choke open. The engine has a multi year warranty that it will start on the first pull, and it does. This setup works so well that my 7 year old son can even start the 6.5 hp engine. The closest this setup has come to giving me any trouble in the past few years was this spring. The engine balked at the first cutting of the season, and I had to pull the string a second time to start the engine.