Johnson 1990 GT150 lower jets

[ben74820]

By no means am I a boat motor mechanic but I can do minor stuff. My question is my GT 150 won't plane out unless you choke it. It will just die unless you do this. I have had it setting in my garage for 2 years. I was told it needed the lower jets cleaned. Is there a easy solution? Maybe some type of cleaner to run thru? Thanks for your ideas. Ben

 

[Chris1956]

Re: Johnson 1990 GT150 lower jets

Ben, Normally you would want to clean the entire carb, and perhaps install new gaskets and inlet needle and seat. The carb kits are available many places on the web as aftermarket for $10-15 ea.

 

[tashasdaddy]

Re: Johnson 1990 GT150 lower jets

Welcome to iboats. seeing it's been sitting 2 years, you need to go thru the awakening process, install a new impeller, dismantle the carbs completely, removing all the jets, soaking in carb cleaner, blowing out with compressed air, and reassembly with a new carb rebuild kit. thats just from sitting 2 years.

99% chance your problem is cause by dirty high speed jets, or a weak fuel pump, air leak in the fuel line, closed vent on the gas tank. having to choke the engine, means it is not getting enough fuel to run at high speeds.

if careful not to move the linkage you should not have to do a link n sink. you can go to brp-johnson, engine diagrams to view a blow up of all engine parts. the jets are hidden behind plugs that have to be removed, and you need a special tools to remove the jets, the tool can be made from a quality screwdriver. there are no dumb questions here, so ask. heres a couple of links.

http://forums.iboats.com/showthread.php?t=158086

http://www.evinrude.com/en-US/Accessories/Literature/

http://i155.photobucket.com/albums/s311/frankr_photos/FixedJetScrewdriver2.jpg?t=1177353186

parts can be bought from the dealer, online, but, we like to support the benefactor of this free forum, buy buying from the i boats marine store at the top of the page. clik johnson parts.

 

[Walker]

Re: Johnson 1990 GT150 lower jets

Yep, needs complete carb overhauls. I do disagree with the manuals that say to remove the jets. Use a good carb soak and aerosol carb cleaner and compressed air to rinse and dry after the soak and you should be able to see the jets and acertain that they are clean and clear. I read too many time on here of guys that remove all the jets to clean and then they don't know which jets go back where.