Hey
Ive got a 1989 Johnson 70hp outboard which is running with the VRO disconnected. Its still using the fuel pump side of the VRO though as a fuel only pump was not put in to replace the VRO. I am mixing fuel precisely at 50:1.
I have put brand new Champion QL77JC4 plugs in it and performed a compression test with the following results:
Top cylinder 130psi
Middle cylinder 126psi
Bottom cylinder 123psi
My problem is that it fouls all 3 plugs badly. So much so that it causes it to miss and stall during light throttle. It is fine however at WOT. I have had a look at my carbies and I think I have got the early production version which do not have needle valves for adjustment etc.
I have notice that sometimes when i Tilt the motor back after use a little bit of unburnt fuel comes out of the air silencer. But it is a very small amount.
Any help would be appreciated
Ive got a 1989 Johnson 70hp outboard which is running with the VRO disconnected. Its still using the fuel pump side of the VRO though as a fuel only pump was not put in to replace the VRO. I am mixing fuel precisely at 50:1.
I have put brand new Champion QL77JC4 plugs in it and performed a compression test with the following results:
Top cylinder 130psi
Middle cylinder 126psi
Bottom cylinder 123psi
My problem is that it fouls all 3 plugs badly. So much so that it causes it to miss and stall during light throttle. It is fine however at WOT. I have had a look at my carbies and I think I have got the early production version which do not have needle valves for adjustment etc.
I have notice that sometimes when i Tilt the motor back after use a little bit of unburnt fuel comes out of the air silencer. But it is a very small amount.
Any help would be appreciated