Yamaha rough at low speed

[pcs9119]

I have a 1999 Yamaha 130HP Saltwater Series outboard that runs real rough from 0-10 MPH. When I throttle up, it runs like a top.<br />Could this be a simple carb adjustment?<br />Any advice greatly appreciated.<br />Pete in FL

 

[Capt Ken]

Re: Yamaha rough at low speed

Simple answer, if it use to run smooth like it sets but just recently started running rough, no,adjustment usually won't work. If it has always run rough, maybe. I would first check compression then spark. If both of those checked out OK, then probably the low speed jets in the carbs are dirty. They are teenie tiny things anyway and easy to become fouled.

 

[dkondelik]

Re: Yamaha rough at low speed

100% agree with Capt Ken.<br />First make sure that your working with a fundamenatlly sound motor. Check compression- all cylinders should read within 10% of each other. Confirm good spark on all. <br />IF above checks out, then onto the carbs.<br />Stronghly suggest aquiring a service manual. Personal opinion- I have used Clymer, (WAY TOO GENERIC) and Seloc (a bit better then Clymer). Get your hands on a factory manual if you can (they're out there somewhere).<br /><br />Good Luck!<br />Have Fun

 

[Forktail]

Re: Yamaha rough at low speed

Link and sync?

 

[DJ]

Re: Yamaha rough at low speed

p schmidt,<br /><br />I had a Suzuki DT 140 that was prone to those symptoms. It was always the carb. jets. <br /><br />No matter how fresh/clean I kept the fuel, it was a seasonal job to clean the low speed jets.

 

[pcs9119]

Re: Yamaha rough at low speed

Thanks to all for input.<br /><br />Assuming problem is dirty low speed jets, is there a fuel additive that will clean them? If not, is this something I could do myself - I have no outboard experience . Would a manual be necessary?<br />Thanks again to all.<br />pete

 

[moderator1]

Re: Yamaha rough at low speed

pete,<br /><br />Yes, you can do it. Just take your time and get the manual.