Not sure whats up with my starboard motor. fired up this morning, started fine, sounded good, put it in neutral and it increased in rpm ok, but after a few minutes of warming up it would only go to about 1500rpm in neutral, but if i put it in gear it would move right up in rpm.....any ideas?
any ideas?
- Thread starter fastal
- Start date
Gman25
GreatGrady Captain
I really cant imagine any situation where an engine under load makes more rpm's than when not under load (neutral) . Therefore I'm guessing that it has to have something to do with your helm/linkage. Check your control box and throttle linkage and see what happens (or doesn't happen) when you put it in neutral and rev it. Sorry, that's all I've got. Good luck
How are you increasing revs without being in gear? Are you using the shift overide button?
I also agree that my take would be a binacle problem or perhaps a throttle linkage issue at the motor but even then the symptoms are weird. I would remove the engine cowling and take a look at the throttle linkage to see if the problem is there first. It's probably not. Also look to see if the throttle cable continues to move as you attempt to rev up.
Strange indeed.
The more I think about this the more I lean towards a binnacle problem
I also agree that my take would be a binacle problem or perhaps a throttle linkage issue at the motor but even then the symptoms are weird. I would remove the engine cowling and take a look at the throttle linkage to see if the problem is there first. It's probably not. Also look to see if the throttle cable continues to move as you attempt to rev up.
Strange indeed.
The more I think about this the more I lean towards a binnacle problem
Gman25
GreatGrady Captain
If you are talking about rev-ing the engine while its in neutral using the override button on the throttle, I was told when I bought my '02 200 HPDI's to NOT do that..Even when starting cold. The computer will advance rpms as it needs it. No choke-no advance throttle..Just turn the key.......I was also told not to "click" start....You have to turn the key until the engine makes one full revolution.
'05 300 Marlin F250's
'05 300 Marlin F250's
was using the override to increase rpms while not in gear. did the same thing for the port motor and was able to increase gradually to about 2300 as I normally do every year.
Would it be correct to assume that your engine's basically run fine and that your questioning why one engine has a difference of 800 rpms when revved to the max in neutral...or is it something more than that?
Fastal, email Andy at SIM and ask him, let us know.
I have the same thing but it differs between twins.
He may say only 2 or 3 pistons fire in neutral but be specific that it USED TO REV higher.
No motor is supposed to be manually rev'd up in neutral, 2 or 4 stroke, car or boat, it's all the same.
What over-ride button? It is either in gear (loaded) or neutral (unloaded).
I did have a problem with one where it would not rev up at all in neutral, would just stall upon opening throttle even slowly, and barely idle, I changed the two LP vacuum fuel pumps per motor and cleaned the O2 sensors (new one on one motor), every gas filter (as usual), fixed it. But one motor does go higher but I'm on the drydock out of water (no backpressure on exhaust). When I kick it into gear however, it is ready to rocket !
Your throttle plates may have to be "synced" to open/close at same time if off a bit (Andy will email a procedure if you don't have manual), check spark on cylinders, perhaps weak coil.
I have the same thing but it differs between twins.
He may say only 2 or 3 pistons fire in neutral but be specific that it USED TO REV higher.
No motor is supposed to be manually rev'd up in neutral, 2 or 4 stroke, car or boat, it's all the same.
What over-ride button? It is either in gear (loaded) or neutral (unloaded).
I did have a problem with one where it would not rev up at all in neutral, would just stall upon opening throttle even slowly, and barely idle, I changed the two LP vacuum fuel pumps per motor and cleaned the O2 sensors (new one on one motor), every gas filter (as usual), fixed it. But one motor does go higher but I'm on the drydock out of water (no backpressure on exhaust). When I kick it into gear however, it is ready to rocket !
Your throttle plates may have to be "synced" to open/close at same time if off a bit (Andy will email a procedure if you don't have manual), check spark on cylinders, perhaps weak coil.
I don't think that motor(ECU) knows if it is in gear or not. There is no issue either using the shift lockout button to allow more throttle while in neutral although I don't recommend high revving in neutral.
Is the problem that you can't rev any higher in neutral or that for the same throttle position, the revs are different between motors?
Is the problem that you can't rev any higher in neutral or that for the same throttle position, the revs are different between motors?
Gman25
GreatGrady Captain
fastal said:
For what reason? Do you need to increase rpms so the engine wont die out? Not sure what the benefit is(If any)to increase rpms to 2300 while in ur slip....I seem to recall they idled at a smooth 600 rpms and they do it on 4 cylinders while in neutral. All 6 when its in gear.
'05 300 Marlin F250's
no issues with idle, I guess ignorance on my part. I was increasing rpms gradually to warm up motor. It appears this is not a proper procedure on my part.
we look for any anomalies.
When we do our check run before take off we look for any anomalies.
If we find any we would shut down that engine and return to the hanger.
We would never go on if we doubted the instruments or the engines integrity.
I would apply the same to boating.
When we do our check run before take off we look for any anomalies.
If we find any we would shut down that engine and return to the hanger.
We would never go on if we doubted the instruments or the engines integrity.
I would apply the same to boating.
Re: we look for any anomalies.
When you dock the boat, do you return your seat to it's full upright position?
CWOT said:
When you dock the boat, do you return your seat to it's full upright position?