bigtime_mcalpine
Regular Contributor
Went out on the water last night to test an engine and had some issues. Engine started beautifully and idles nicely but taking it past 1/3 throttle was a bit of an adventure. At first it might be fine but then power would go down to almost idle then maybe come back up but then come right back down again. If throttle was up too high for too long it would stall. I swapped out the fuel pump before going out on the water but it made zero difference. Did this a few times and then the engine became hard to start unless I let it sit. Felt like I was flooding it. Didn’t seem to really respond to bulb being pumped but the rev’ing up and down was so erratic that it might have, not sure.
So…brought it home and pulled the carb apart (again!) and inspected the high speed jet closely. Clean as a whistle. Entire carb looks perfect. Gaskets are in good condition, needle is fine, etc. Fuel hoses are all new, fuel pump mesh is clean.
I then went right back to basics and pulled the plugs. Well…a) they were NKG 7HS which is not spec for the 35hp 1987 engine AND the gap was .04. The 7HS are spec on some more recent 10’s and 15’s. So my question is this, would incorrect plugs and large gap cause the issues I’ve been experiencing? I’d really like to just take this back on the water and test it out but it takes a bit of time/set-up to get to the river so would prefer for the next trip to be a full success.
Fuel is new, tank has been run with other motors without issues. Compression is 105 in each cyl.
So…brought it home and pulled the carb apart (again!) and inspected the high speed jet closely. Clean as a whistle. Entire carb looks perfect. Gaskets are in good condition, needle is fine, etc. Fuel hoses are all new, fuel pump mesh is clean.
I then went right back to basics and pulled the plugs. Well…a) they were NKG 7HS which is not spec for the 35hp 1987 engine AND the gap was .04. The 7HS are spec on some more recent 10’s and 15’s. So my question is this, would incorrect plugs and large gap cause the issues I’ve been experiencing? I’d really like to just take this back on the water and test it out but it takes a bit of time/set-up to get to the river so would prefer for the next trip to be a full success.
Fuel is new, tank has been run with other motors without issues. Compression is 105 in each cyl.