Power Loss on Mercury 9.9

[boaterchal]

Hi, <br /><br />I have a 9.9 98 Mercury. It hasn't been run in 4 years and only has at most 10 hours on it. Drained all the gas and put new gas, change the gear lube but not the plugs yet.<br /><br />Just took it out for a test spin, all ran well at around 5000 rpm for 15 minutes and very snmooth then all the sudden dropped to 4000 and couldn't get back up to 5000. I'm not sure what is going on and don't know much about outboard motors. Any advice and suggestions is very appreciated.<br /><br />Thanks

 

[Keefbikes]

Re: Power Loss on Mercury 9.9

If you had it in storage and didn't drain the carbs you need to start with cleaning those. Next change your plugs or clean them, they may have old oil goop on them causing a missfire. It sounds to me you lost a cylinder thus slowing the rams, but it may be as simple as a carb adjustment. Your carbs can gum up if left for only a few months. If this does not work take it in to a reputibal dealer. DONT TRY TO SAVE A BUCK!! OR YOU WILL END UP WITH A BUCK IN YOUR POCKET AND A EXPENSIVE 9.9HP ANCHOR.