This thread covers solutions to common questions in relation to operating our ENCLST1_12, ENCLST1_13, ENCLST1 10hp engines. Some of the posts may also cover ENCL65 and ENCL35 engines.

ENGINE NOT REVVING PROPERLY

There are probably 3 most likely reasons your engine is not revving as it should. Try checking the following:
1. Pump efficiency and air/fuel ratio inside the head compromised by leak at vacuum pickup point.
This is a double-whammy effect where if there is a leak at the little barb in the black insulator between the carb and the head (either from the barb coming loose, or the vacuum line loose/not clamped tight enough). It will slow the pump so not enough fuel may be present, or it can allow air to leak into the air/fuel mixture after the carb causing a lean condition. Check the line is secure and the clamp is tight. Check the barb is not loose. If the barb is loose it can be glued back in using a resin glue or a plumbers glue.
2. Fuel starvation - this can happen for a variety of reasons, including the detail outlined above. Check that the line from the pump to the carburettor is not damaged or blocked and is properly secured to both the barb on the carburettor and the barb on the fuel pump. Check that the line from the pump to the fuel tank is not blocked, and that a fuel filter (which you should ALWAYS use) is installed and not blocked. Check that the fuel tank has ventillation and is not creating a vacuum inside. It's surprising how many times we find that external fuel tanks are either blocked, or do not have any ventillation. At minimum there should be a very small hole drilled in the filler cap to allow the pressure to equalise as fuel is depleted from the tank. If you have added any new parts (freer flowing muffler or air filter, or changed a carb) ensure that the correct jet size is being used. If you are using the stock carb supplied with your engine and you bought the ENCLST1 engine from CPR then you will have the correct jet installed.
3. Valve clearances incorrectly set. You will need a feeler guage to check your valve clearances. You can usually check this by hand fairly easily to see if it's causing a problem if the rockers have become unusually loose. Firstly remove the spark plug and the fuel line and vacuum lines from the fuel pump. Turn off the ignition at the kill switch on the flywheel cowling. Remove the four bolts holding the silver OHV marked rocker cover and remove the rocker cover (note it will be oily so set it aside on a rag). Turn the engine over slowly using the pull starter and feel the slack in the rocker arms by gently rotating them slightly and rocking them back and forth. There should be enough movement that you can feel at certain points in the engine rotation they feel just loose. If they are very very loose then valve clearances need to be reset. You can check the correct clearances using the details in this post: http://www.cutpriceracing.com.au/phpbb3/viewtopic.php?f=13&t=246