View Full Version : Holley 4150 Carb Rebuild

04-27-2011, 08:46 PM
I just recently successfully rebuilt my Holley 4150 Carb off a Indmar 310.
It came out of my 2006 Mobius LSV.
If anyone has any questions or would like help with a similar project please feel free to ask.
I had never done it before, learned a lot, made a few mistakes, but went from a non-running boat to a boat that runs super good.
Anyways, hope you all have a trouble free summer but if you get in a tight spot I'd love to help if I can!

04-27-2011, 08:53 PM
Cool,most guys seem to be a little afraid of that project.

04-28-2011, 01:28 PM
Dang proud of you. Wish you would have done a full pic HOW TO though for the carb guys on here. Maybe next time.

05-06-2011, 08:03 PM
I have had my boat out a couple times since rebuild and it runs strong!

I do have a question for those of you who are more savvy than me on tuning the 4150 Carb?

When I drop in water for first cold start, it will not start unless I turn in main idle screw about 1.5-2 full turns. Then it fires right up but obviously is idling high (1500-1600 RPM). The choke then goes through cycle opens completely and then i can turn out idle screw to normal value (~850-900 RPM).
The boat will then start fine for the rest of the day at that idle screw setting?
What am I missing? Float levels seem correct. Air mixture are at 1.5 turns out and it idles great?
Thanks for all responses....It's finally warming up out there. My 11 year old daughter just had her first set on Monday! We had the whole lake to ourselves....

05-06-2011, 08:17 PM
if you do a step by step, maybe even pics if you have them it would be a great how to for the how to forum

05-06-2011, 08:19 PM
my buddies '94 boomerang would not run this spring. he had too much fogging on the plugs he replaced last fall. while tinkering, I noticed that his carb is horribly dirty. I have never had much luck with them. an faq would have been nice. I told him to get his neighbor to do it for him :(

on the positive, cleaned the plugs and it's running awesome, but does need a carb clean/rebuild.

05-31-2011, 11:14 PM
On your carb rebuild bludpumper did you notice any flaking internal to the carb/fuel bowl? My fuel bowl was leaking about half through this last weekend. Noticed the fumes while out on the water and saw that gas was dripping on a hot engine! Ouch! Tried to tighten the fule bowl screws and cracked the bowl causing it to leak more. End of our weekend on the Moomba anyway. I have 2006 LSV with Indmar 310 and Holley 4150. I pulled the bowl off, cracked threaded fuel inlet in the process, and later put my finger through the side of the bowl. It was very brittle and flaking significantly. I found today that Holley apparently has reported casting issues with 05 and 06model carb fuel bowls. I am calling first thing tomorrow and hope to get mine replaced as I have found other examples of exactly what mine looks like on auto repair forums. Will post and update after I talk to them. But if you have this setup, definitely check the fuel bowl. I cringe when I think about this crap floating around the engine.

With respect to starting, at least prior to this issue, I always have to prime for awhile before I get going on a cold start. I have thought it was electric choke issue but not sure. I have started using a shot of starting fluid into the carb and it starts right up. Saves starter and battery alot of stress. Hopefully no side effects from this approach.

Thanks, Hutch

05-31-2011, 11:39 PM
Thanks for the response. Sorry to hear about your troubles. Unfortunately I can relate for sure.
I was a novice going into this project so I just thought it was some kinda of carbon build-up or something. I had no idea it might be a manufacturing problem but that makes sense.
Take a look at my pics. I think mine might have been worse even. Ya that crap was everywhere. I just scraped mine down and cleaned real good but I'll check with Holley too. The more they hear about it the more likely they will take care of it?


There are more pics in that album if you follow the links.

Thanks for sharing let me know if you encounter any problems along the way on your rebuild. i found the rebuild kit on amazon. It is specific to the marine 4150s.
This is the link to buy it if you haven't found one yet:

Good luck!

06-03-2011, 08:03 PM
So I talked to Holley today...Ricky in tech service. I gave him the list number from the carb (75021-3; 1156) The second number indicates 2006 year and Ricky said this was one of the units with casting issues. So he has asked that I remove the whole carb, send it in and they will send a new unit. Not sure if this does anything for you bludpumper but even after your rebuild if you have a number close to the one above might be worth making the call. 1-866-GO-HOLLEY For all who have a 2006 4150 model carb I would check the fuel bowl (easy to remove) and see if you have any of this flaking. I was baffled as to how the inside of the fuel bowl could look as bad as it did.


06-04-2011, 03:28 PM
Thanks for the info. Yes if you looked at my pictures, my fuel bowls were doing the same thing. I'll definitely give Holley a call after I check the number on my carb.
I appreciate the follow-up. hopefully we'll save some people some headache!


06-06-2011, 03:35 PM

I looked at my carb today and I have exactly the same model as you. Spoke with a guy named Sean at Holley and he said a replacement would be no problem. I'm gonna wait a few weeks to send mine in as I don't want to be without it during that time.
Let me know if you get yours replaced so i know how it went and what kind of turn-around they do on the new unit. Again thanks for the info.
Wish i had of know about this a couple months ago!


06-06-2011, 05:58 PM
well better late than never I suppose, glad to hear they are going to support it though...I am hoping to get mine back this weekend...Ricky said he would turn it around quickly...so I will let you know. Couple of questions on the rebuild kit though from Amazon...does it include the large black gasket between the carb and the engine? also any chance it includes the tension spring that puts pressure on the throttle lever? the large gasket looks like it should be replaced and the spring broke when I was taking it off.

thanks, Hutch

06-06-2011, 07:04 PM
The gasket that comes with the kit is not as thick as the original, but has the correct bolt pattern and seems to work great on mine. (One thing to note though is the length of your hold down bolts. If they are super long then you might need the thickness of the original gasket to get a tight fit or shorter bolts.) Mine were short enough to secure nicely with the new thinner gasket.
You could probably get this at an auto part store due to the fact that the 4150 is common and the pattern should be the same. Just a guess, but I know they stock some Holley parts at my local Kragen.
The kit did NOT include the spring but I'm sure that you could get one at an auto parts store as it is pretty common and the amount of tension is not super critical. It just needs to pull back to neutral.
Those parts separate should be pretty cheap whereas the whole rebuild is almost $50 or so.

Hope this helps.


06-21-2011, 04:44 PM
just to close the loop....I received the new carb from Holley on a Wed...had sent it on a Monday the week before, it arrived on Wed and they said they ordered and sent the new carb via UPS ground the next day. So pretty good turnaround considering... I was able to reuse the old spring and Holley sent a new spacer with the carb. Installed the new carb in less than 30 mins and up and running....I adjusted the idle to about 800 and haven't done anything else to it. Now my choke works great whereas before I always took awhile to get the engine primed... so far so good, and very happy Holley provided the replacement after having the issue with the casting.


06-22-2011, 02:15 PM
Thanks for the follow-up. You must have got the last carb in the warehouse! They are making me one and will send when it is done.
Can you tell me if the new carb comes with the chrome duel fuel supply or if you kept that when you sent yours back?
Glad to hear yours is back in great running shape. Hopefully mine will be soon too.
Double up!


07-18-2011, 10:47 PM
Sorry Josh..missed this one. It did not come with the fuel supply line. I reused mine. It did come up with a the large spacer. Have you received the new carb yet?


07-19-2011, 12:09 PM
Thanks for the reply Hutch. Yes I received my carb, it installed no problem, and have been out on the lake about 5 times with it so far. Works great. Thanks for your help. I really appreciate it and props to Holley for standing behind their carbs.
Have a great summer!

09-07-2013, 08:31 PM
I just recently successfully rebuilt my Holley 4150 Carb off a Indmar 310.
It came out of my 2006 Mobius LSV.
If anyone has any questions or would like help with a similar project please feel free to ask.
I had never done it before, learned a lot, made a few mistakes, but went from a non-running boat to a boat that runs super good.
Anyways, hope you all have a trouble free summer but if you get in a tight spot I'd love to help if I can!

I have a Moomba Outback 2006 310 that does not run right when I reach 30 to 35 MPH. The engine loses acceleration. Although I keep the throttle lever at the same position, the engine will decelerate and then after a few seconds, it will accelerate again. It continues until I throttle down to a lower speed. At low speeds, the boat runs fine.

So far, I have done the following:
Replaced distributor cap and rotor
Spark plugs
Fuel filter
Sea Foam in the gas
Sprayed Carpuretor cleaner

Yet, no luck in resolving the issue.

Do you have any ideas of what may be causing this? I feel that it may be related to the carburetor.

09-07-2013, 10:50 PM
Sounds like bad gas to me. Add another can of sea foam and fill up with fresh gas. I had a similar problem and after about 15 min of running the boat it was Resolved. Let me know if that works.

Good luck!

09-07-2013, 11:04 PM
Thanks for the advice. I plan on siphoning the gas and refilling with fresh gas and more sea foam.
I will let you know if it resolves the issue.

09-09-2013, 02:08 PM
Waiting for my carb rebuild kit to come in this week. Then see how she goes. The carb was dumping way too much fuel as the floats were stuck or the needle was pushed up.

04-28-2014, 06:30 PM
(reviving and old thread)

Did you guys tear the carb completely down for the rebuild?

When I called Holley for the rebuild they didn't mention anything about a recall, guess I'll find out when I open it up..