2003 ox66 225hp starting issues

[dricha21]

Lately my motor has been a little hesitant to start after being run a while. It has always started very easily. Hit the key and it was running. I changed the plugs but it didn't help. It is inconsistent when it does it. Sometimes it does it and sometimes good. I have to hit the key sometimes 5 to 10 times before it stays running. Definitely seems like a fuel issue but not sure. I have never had to pump the ball to start this engine but that is what it seems like it is a primer ball issue. The inconsistencies of it is driving me crazy. Any suggestions?

[Amistad Tackle]

Could be several things. Possibly low pressure fuel pumps. Easy to check. Loosen them from the block. If they leak any fuel they should be replaced. Those pumps go out all the time.

[CJ1]

Once it runs, does it smoke more at first? Act flooded? "lp fuel pump bad. As was suggested. Or is it lean, as in better when you prime it? Cleaned your o2 sensor recently along with filters. I think it is harder on our outboards as we normally cant use them 6 months out of the year. CJ

[dricha21]

Once it runs, does it smoke more at first? Act flooded? "lp fuel pump bad. As was suggested. Or is it lean, as in better when you prime it? Cleaned your o2 sensor recently along with filters. I think it is harder on our outboards as we normally cant use them 6 months out of the year. CJ

I will have to research cleaning the o2 senser. I replaced lp fuel pumps last year. Hope it is not that.

[dricha21]

I cleaned 02 senser today and it was really carboned up. The senser itself wasn't real bad but the senser body was carboned up very bad. I will find out tomorrow when I take it out.

[M-D]

I cleaned 02 senser today and it was really carboned up. The senser itself wasn't real bad but the senser body was carboned up very bad. I will find out tomorrow when I take it out.

Keep us posted please.

[Amistad Tackle]

Never had any luck cleaning the O2 sensor. Replace it with the NTK 21006. Only $35 on Amazon. You'll have to use your present harness and splice/solder it in. I have the same engine and have been using the NTK for years. I just change it every year.

Those low pressure pump(s) can go bad after one trip. Been there. Check them.

[CJ1]

I cleaned 02 senser today and it was really carboned up. The senser itself wasn't real bad but the senser body was carboned up very bad. I will find out tomorrow when I take it out.

You need to clean the siphon tube also. Need to have a clean hole going through it. Cj

[dricha21]

Cleaning the 02 senser did nothing and it ws really carboned up. Just ordered 3 lp fuel pumps. Supposed to be here friday

[dricha21]

Where is the siphon tube?

[Amistad Tackle]

Behind the fitting that holds the O2 sensor. It brings gases from the top cylinder to the O2 sensor. That tube needs to be pulled out and cleaned. If nothing else a lot of times there is carbon build up or oil in the tube. You may need a new gasket or two. Take a look at the parts diagram to see what you might need.

Somewhere on the web there should be some photos of cleaning the tube and replacing the O2 sensor. I have never had the tube completely blocked but it has had carbon build up and like oil granules around it.

[javelin90]

At one time the post had pictures. I had printed off the repair information and pictures. I will look through my repair book and try to upload on here.

https://www.bbcboards.net/showthread.php?t=33301