Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Firing order 1-3-4-2. With left bank being # 1 closest to the flywheel, and # 3. #2 nearest flywheel and #4 are on the right bank. Check compression , spark, and check for intake manifold gasket leaking.
Here is the service manual link , if you need it. Link below.
I see question is still open, did you find problem?