Carburetor Repair Kit Skip the New Carburetor

When a carburetor goes wrong, most of the time you do not need to replace the whole thing. The RB-155 repair kit is exactly that, the few pieces that should be swapped, packed together.

After a few years on a trimmer or blower, what actually fails inside the carburetor is the rubber and a few small metal parts: the diaphragm hardens and stops pumping, the gaskets age and weep, the spring tires, the needle valve sticks. The carburetor body itself is still good, and paying for a new carburetor just for the body is not worth it. The kit's point is this: take the parts that wear, pack them together, and in one teardown swap all of them, the body keeps working.

What are the black rubber pieces for? One is the metering diaphragm, a rectangular flange, a metal plate in the center, five large holes around a small pin, fitted into the metering chamber, swelling and contracting to draw fuel into the carburetor. Hardened, cracked, or the holes worn ragged, and it is its turn. The others are gaskets; the square one with the large center hole is the main gasket, seated between the carburetor and the body to seal the joint, and the shaped ones each cover a different chamber on the carburetor, wherever one leaks, that one is swapped, and the kit has them all.

The small metal parts? The spring handles the return and the tension, and when it tires the valve does not follow your hand. The needle valve cuts the fuel, and when it is dirty or stuck, the fuel will not shut off. The pins and clips are the locating pieces, the easiest to lose on a teardown. Bought one by one they never come together, and the kit gives the whole set at once.

When to reach for this kit? Rough idle, no acceleration, needing several pulls to fire, fuel weeping under the carburetor; open it up and the rubber is all aged, and that is the time to rebuild. One teardown, the pieces in the kit matched to their spots and all swapped, cheaper than a new carburetor, and outlasts swapping one piece and making do.

What to watch when fitting it? Lay the old parts out as you take them off, and match the pieces in the kit against them one by one, each to its own spot, do not cross them. Fit the gaskets dry with no oil, press the diaphragm flat with no wrinkles, the spring the way it was, and test that the needle valve drops back. Once fitted, start it and check the idle is steady and the joints do not weep. Carburetors in the same family mostly fit, but fit is not guaranteed for every one, so comparing against the old parts is the safe way.