029 carb leaking - pressure test?

[Bob95065]

I am working on an early 029 that has ben a nightmare rebuild. I have it back together and it has an erratic idle. This was confusing because it passed a pressure/vacuum test. I had it running and sprayed some brake cleaner around the carburetor and the engine died. This makes sense because the carb was replaced with a block off plate for the test..

How do you test a carburetor? I did rebuild it. I want to determine if the carburetor is the problem or the OEM intake boot I put on it before I buy another boot.

Thanks.

Bob

 

[cookies]

remove the boot and check it over very carefully for cuts and cracks, also check the impulse hose the same way...if both are good then you need to check where the carb presses against the boot and that you have the boots inner and outer plates that prevent the boot from disforming when squished.

 

[Bob95065]

remove the boot and check it over very carefully for cuts and cracks, also check the impulse hose the same way...if both are good then you need to check where the carb presses against the boot and that you have the boots inner and outer plates that prevent the boot from disforming when squished.

When I did the pressure test I plugged the impulse line and put a block off plate in place if the carb. It passed. Before the test I replaced both the boot and impulse line.

Yesterday I pulled the carb and checked to be sure the boot wasn't deformed. Looked correct

 

[heimannm]

The carburetor should hold 7-10 PSI if you connect your pressure tester directly to the fuel line fitting. If it does not, check the metering needle, the seat, the spring, and the metering lever. Sometime a little polishing of the needle & seat will cure a leak, I slip a piece of small diameter tubing over the end of the metering needle so I can spin it back and forth against the seat. If the metering lever is set incorrectly that could also be an issue.

It could also be a high speed check valve leaking, that can cause it to run excessively rich at idle, I am not familiar with the 029 carburetor so someone else will have to chime in on testing that model.

Mark

 

[stihltech]

Carburetor-if you see any corrosion, dump it. The check valve is a good suggestion. I have seen a few of those leaking.
If you want to do it inexpensively follow the above directions. If you don't want more frustration, or it still does not work, replace the carburetor.
In the shop. it is cheaper to replace. The saw will act like new. Plus kits and labor will usually end up at he same cost. AND I have to guarantee the repair.