Motor is sneezing

[30pound-tasty-fish]

I have an 89 Merc 90HP oil injected unit. When I am at idle, regardless if the motor hot or cold the motor "Sneezes" About every 10 seconds and the rpms drop from about 1000 to 500 for about a half a second.

I have read some posts about this but I am wondering what is the main culprit for this? My plugs are less than a year old. What should I tackle first?

Thanks gang,
~30#

[Lou]

It's starvation of some kind. Small hole in the fuel line.
Possible a small hole in fuel pump gasket.
What have you checked?

[Just-in-Time]

that is a lean sneeze
clean the carbs and re-sync

[fishkisser]

Could be the carbs need a good cleaning , but it could also be worn reed valves , improper oil mix at idle , too much air (faulty manifold gasket ) its usually one of three things on a 2 stroke that affect the fuel mixture recipe, air, fuel and oil ...
If this is a lean sneeze it could cause a lot of damage if your motor is running lean on higher R P Ms but sometimes the oil ratio is not the same on injected motors at idle as it is at lets say 2500-4000 ...
How did the plugs you replaced look ??? An eroded electrode could mean you are running way too lean and could result in piston damage or seizure ...
Barney ...

[NWaddict]

You're probably past this step but I'd first make sure you're getting good pressure in your fuel line. It definatley sounds starved for fuel.

[30pound-tasty-fish]

I ran out and checked the plugs they all look healthy, no scorching. I fired it up in the driveway and could not get the thing to sneeze. It ran like a top.

It might just be time to take her into Steven's for a tune up and a good look at the carbs and fuel system.

[ET]

Originally Posted by Just-in-Time

that is a lean sneeze
clean the carbs and re-sync

That's the ticket!

You might get lucky with just putting some carb cleaner through it and filling with fresh gas.

[Just-in-Time]

no such thing as a mechanic in a can
yes it might help, but it is just a band-aid

[fishkisser]

Originally Posted by Just-in-Time

no such thing as a mechanic in a can
yes it might help, but it is just a band-aid

Hey J I T hows about a customary fish story and introduction posted in ifish community ?
Its always nice to here whats what about a new member ...
You also might want to proofread your location ...
Let me be the first to say welcome to ifish ...

[Just-in-Time]

Ya my T on my puter sticks sometimes, LOL

I'm just going to stick with the motor side of things, I have no time to FISH!

[fishkisser]

Originally Posted by Just-in-Time

I'm just going to stick with the motor side of things, I have no time to FISH!

You are kidding right ... Or maybe not ...

[Just-in-Time]

I'm not
i run around from the yacht club daily, then over to other peoples boats

my free time I'm racing my jet ski on the weekend, and it is a stand up not a sit down!