Evinrude 9.9??????

[Ryan0186]

I have searched all over google and Iboats forum for an answer and have not found a defining one yet. I recently purchased a 1991 Evinrude 9.9 from a buddy of mine. Since I got it I have rebuilt the carb ( it was the first time I had ever cleaned a carb so I didnt adjust the float needle valve), cleaned up the plugs, and changed the water pump and L/U oil. When I first got the motor it had been sitting up for many years, Would not start. After I rebuilt the carb it started on the second pull and would idle for about ten seconds and then shut off with choke off. I noticed that the primer bulb was not staying firm so I figured it was the fuel pump. I ordered a new one off the Iboats web site and it will be here Tuesday. Hopefully that's the problem. Next problem I am having with it starting today is that the motor will only idle or run when it is at half or full choke. After running for about 10 seconds and it starts to sound like its going to shut off like its run out of fuel, I can pull choke out all the way and it will run good again. I also pulled the plugs and noticed that they look black and sooty. Motor will also only start when fully choked, and only idle when at full or half choke. I was told it could be a few things things....

1. Cracked diaphram in the fuel pump
2. clogged or dirty carb
3. un-vented tank
4. fouled or cold plugs

Is there anything else I need to check? I have fresh gas flowing through it and a well vented tank. I also used three different fuel lines with the same result. what would cause it to only run when fully choked or half choked?

As far as the issue with fuel delivery, I am going to clean the carb up one more time, correctly adjust the fuel float this time, change out the old plugs for new ones, and install the new fuel pump and see if i can get it idling again.

I know this is a long rambling post, sorry if some of it sounds unclear. Thanks for all the help guys and happy boating!

-RYAN

 

[bktheking]

Re: Evinrude 9.9??????

Well first things first, the bulb only stays hard for priming , after that it doesn't stay hard. Did you put a new kit in the carb when you cleaned it? May not be a pump issue and be a carb issue still, usually pulling the choke to straighten it out means the carb is still dirty.

 

[Ryan0186]

Re: Evinrude 9.9??????

First I want to thank you for your quick reply . When I rebuilt the carb I didn't use a new carb kit. I did check the float needle and it looked good. The tip was not gouged or worn in any way. I guess I should just go ahead and order a new carb kit from Iboats. Ill try cleaning it again and adjusting the needle. I borrowed a factory service manual from a friend of mine today so when I rebuild that carb im going to follow the steps in the manual. Ill let you guys know how it turns out. Thanks again for the help.

-RYAN

 

[bktheking]

Re: Evinrude 9.9??????

No problem.


Well cleaning it involves removing welch plugs and lead shots, parts that come in a carb kit.

 

[Ryan0186]

Re: Evinrude 9.9??????

So I replaced the fuel pump and rebuilt the carb from top to bottom yesterday. I had a heck of a time trying to remove the bonnet that the float needle sits in. I sheared the head of it off in the carb body and had to use a tap and die kit to re-thread it for the new bonnet. After hours of cursing and fighting it I finally got it back together and it started on the first pull. Runs great with choke off and idles beautifully now. Mounted it up to the boat and runs great. Thanks for all the help guys!

-RYAN