Do these simple tests:
1. Start the engine cold. If it starts easy with just a few seconds of cranking then the compression
is ok and the injectors are probably ok.
2. Check for an oil
sheen on the water immediately after startup. If none, then the injectors are definitely ok.
3. Open the valve cover cap- where you add oil
, and put your hand over the outlet. If you don't feel pulses of exhaust
then the compression
and valve guides are ok. This test is not really necessary if #1 is good.
4. Run the engine at wot in neutral for a few seconds. Does it hit rated rpm
plus a hundred or two. This tells you if the governor is ok.
5. Once you determine #4 is ok run the boat at wot for ten minutes. Does it reach rated rpm
? Does it overheat? Does it make a lot of black smoke? There are several reasons for not being ok but probably the most common is a plugged exhaust
If all of these tests turn out ok, you are probably good for thousands of hours of uninterrupted service from this engine.
BTW the spares kit is a good price
for what it covers and the injectors are worth the price of the kit, but you don't need 4 injectors. Two will do and make sure that these are well protected from rust.