raptorheli2
Recruit
- Joined
- Aug 24, 2006
- Messages
- 4
Hi folks,
looking for some help if possible.
my 75hp 3 cyl mariner (1998) oil injection has been flawless since i got it new until recently. this past season midway through it the motor started to idle really badly intermittently to the point it would cut out until it had a good run. it would normally be ok for rest of day. next time out it may do the same or may work fine.
engine starts fine i should add.
the symptoms i'm seeing are when you start it there is excessive smoke and there is large amounts of oil in the water (unburnt fuel i assume) when sitting at idle. if you go for a run normally this cures itself.
i have taken a PSI reading from all cylinders and all are 92PSI when engine was stone cold. normally i'd get warm readings but i lost the will to live just going to the boat with the cold weather let alone try and let it idle badly for 15 mins to get a PSI reading. i know should get readings on a warm engine but i figure 92 on a cold one is within spec???? i expect it will jump 20PSI or so when warm. going on other forums that seems likely anyway, i will test this when weather improves a little.
i have changed all the plugs and made no difference, got good spark on all cylinders and isn't down on power at all according to the GPS.
i'm thinking i have a carb problem on idle but not sure where to start? i bought the service manual but i thought be better to lean on some expertise here. if need be i'll take the motor to the outboard shop but i'm keen to find the problem myself just for being nosey.
cheers
looking for some help if possible.
my 75hp 3 cyl mariner (1998) oil injection has been flawless since i got it new until recently. this past season midway through it the motor started to idle really badly intermittently to the point it would cut out until it had a good run. it would normally be ok for rest of day. next time out it may do the same or may work fine.
engine starts fine i should add.
the symptoms i'm seeing are when you start it there is excessive smoke and there is large amounts of oil in the water (unburnt fuel i assume) when sitting at idle. if you go for a run normally this cures itself.
i have taken a PSI reading from all cylinders and all are 92PSI when engine was stone cold. normally i'd get warm readings but i lost the will to live just going to the boat with the cold weather let alone try and let it idle badly for 15 mins to get a PSI reading. i know should get readings on a warm engine but i figure 92 on a cold one is within spec???? i expect it will jump 20PSI or so when warm. going on other forums that seems likely anyway, i will test this when weather improves a little.
i have changed all the plugs and made no difference, got good spark on all cylinders and isn't down on power at all according to the GPS.
i'm thinking i have a carb problem on idle but not sure where to start? i bought the service manual but i thought be better to lean on some expertise here. if need be i'll take the motor to the outboard shop but i'm keen to find the problem myself just for being nosey.
cheers