Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Could anyone suggest a fix? I have a small, horizontal shaft Briggs-Stratton engine that I'm trying to set up in a minibike for my son. The model number on the fan/starter cover suggests that it came from a vertical shaft engine at some point so I really do not know the model or power rating.

The carb sits on top of the gas tank and has 2 tubes that extend into the tank. The is one carb adjustment screw on the side of the carb. There is a device at the end of the carb that is manually pulled while cranking that appears to richen the mixture for starting. There is a cover on the carb that opens up to reveal a thin rubber diaphram with a spring underneath it. The pickup tubes that insert into the gas tank appear to be clean.

Here's the problem. The engine will start and it will idle. However, it will not rev up when the throttle is opened. Turning the adjustment screw does not remedy the problem.

Barring a solution, can anyone suggest a source for a relatively inexpensive 3.5 hp vertical shaft engine, 3/4" shaft with key? Jack's Small engines sells them new for $200.00. I'd like to get one for less$$.

Thanks in advance.

if the motor has set for a long time with some fuel in it, its always a good possibility varnish buildup is the problem. at any rate a blockage of some sort, allowing enough fuel to idle, but it fuel starves when attempting to throttle it up. assuming the ignition system is in good shape, and it has good compression, perhaps a good carb cleaning & rebuild & dont forget to give the fuel tank  a good cleaning too.

I agree... It sounds like your carb is gummed up with varnish caused by stail fuel as mentioned. Take the carb apart and clean throughly with automotive gumout spray. Warning...Use goggles or other eye protection when using this product. Do not forget to get the jets clean, the small holes in the adjusment screws. These holes are quite small so don't miss them. Then after your done doing that, if you have access to compressed air, shoot lots of air to finnish the clean. Clean the air filter aswell and change the oil. If the air filter looks too dirty, then just replace it. Please also replace the sparkplug as it coold be partially fouled.

Let us know how it goes.

the diaphragm that covers the little spring is actually the FUEL PUMP of the carb.if it is stiff in any way replace it and try again.

part number is 270026,real cheep fix here.

later chris

Davisah--The guys  have covered this problem so well I have no doubt that a good carb. cleaning and new diaphragm will fix that engine.---Will

I would also replace the gasket that goes between the carb & fuel tank. They are notorious for being overtorqued & can warp from overtightening. Clean out the fuel tank too, & consider replacing it if the tank's insides are rusty or you'll have problems again.

Agreed, a good cleaning & rebuild should get your engine back in shape MUCH CHEAPER than replacing it!

Marty

Took everyone's advice. Cleaned the carb and tank, replaced carb/tank gasket, diaphram, intake gasket and the jet and jet assembly. Started and reved right up.
Thanks for the help.

 DAVISAH,

Welcome to the forum!!

 Stick with us and you will learn a great deal.

I learn something new every day here!!!

                                     Fred   

I am glad you got this fixed! I knew the carb was the culprit. Thoes little carbs can be a pain in the but sometimes.

DAVISA---WELCOME TO THE FORUM AND IT MAKES US FEEL  GOOD TO KNOW YOU CORRECTED YOUR PROBLEM.  MAY GOD BLESS YOU AND WILL BE CONVERSING AGAIN----WILL