View Full Version : Black max xr2 rebuild help

06-25-2019, 10:42 PM
So i bought a bass boat at the end of last summer and was told it had a throttle problem. It will start up fine and idle but once I put throttle to her she boggs out and tries to die or will die once it gets past 1/4 throttle. I can choke it while I give it throttle and it will pick up and run great until I go back to idle then same thing unless I choke it again. Started to dig into it this winter and replaced/rebuilt fuel pump, fuel lines, bulb, filter, shortened fuel hose along with replaced them, new spark plugs and wires, drained fuel tank. I also cleaned the carbs and still have the same problem. Decided to dig into the carbs a little more and found that I am missing the Jet, vent bowl (#2 in the picture) that goes in between the two intakes. Can anyone help me decide what size I need. The options are .096 or .098. The other jets (#20 jet main, idle air bleed) says on it .060. Does it matter which size I go with or is there certain ones that go with the .060 jets?? Hopefully this will fix my problem. Any help is appreciated. My motor is a black max xr2 with serial number A139444

06-26-2019, 07:41 AM
Welcome to the site. Sounds like you have covered the fuel side on the motor. I would get me a portable fuel tank and hook that up to see if the issue is in the boat or the motor. Some tanks have anti-siphon valves and all tanks have vents. Either if these fail and you will have fuel starvation issues. Could laso have generated a pin hole in the pick-up. As far as the missing jet goes there are many carbs that run without vent jets from the factory.


Merc 2.5
06-26-2019, 02:59 PM
Like rock said , almost all modded carb motors run without vent jets , I have all mine out , also most the 2.4s came without jets in 2 and 5 from mother merc, those mainly for mid range anyway, i went thru exact same issue on a mod vp motor , changed complete fuel system and lectrics , didnt fix it , what I came to find out is someone cut the heads on a low compression and raised it back up to 120ish , I put stock set heads on and had bout 70lbs , it was enuff comp to idle and run good on hose but put in water and was a dog ,

With all that said if u hit choke and it picks up ,then need dig in carbs sum more , did u take the top plate off carbs and look at idle and off idle areas, has bunch very small holes that will get easily stopped up

06-26-2019, 03:34 PM
stator, spark boxes, trigger. Old motors love new electrics :cheers:

06-27-2019, 10:31 PM
Just a thought, what elevation do you run your boat at and what pitch prop are you running.
We had to run 2 pitches lower on our props when we went to Lake Powell in Utah

06-27-2019, 10:36 PM
Im pretty sure it's the factory prop. How can I check the pitch of the prop? Depending on which direction I drive I go from 3000 down at sand hallow, Utah to 8800 up at fish lake, Utah.

06-27-2019, 11:06 PM
Im pretty sure it's the factory prop. How can I check the pitch of the prop? Depending on which direction I drive I go from 3000 down at sand hallow, Utah to 8800 up at fish lake, Utah.
Your prop should be stamped on the side of the hub with a number with a P next to it. "19P" Don't know if you are running aluminum or stainless or a big and heavy or small and light fishing boat.
I think a 19P stainless steel at a lower elevation would be in the ball park for running fishing hole to fishing hole.
You may have to run a 17P depending on boat size and elevation.
Find a good boat shop or Prop repair shop near you and ask them.

06-27-2019, 11:32 PM
If it is a elevation issue a smaller prop is a quick fix. You may eventually have to re-jet for thinner air.
Was your boat purchased up near you

06-27-2019, 11:50 PM
It's on a 18 ft bass tracker. And yes I purchased it down the road from my house. Its had this problem since the guy I bought from owned it. I ended up going with the .060 jets because that's what was in it. I'll see what I can find out on the prop. Thanks for the help