View Full Version : Carb Adjustment

07-31-2006, 07:45 PM
I have an 06' Outback with the 310 assault carbed engine. When I give it full throttle all at once it hessitates a little then takes off. I have read that this carb can be adjusted, can someone please explain to me how? When I took it in for my 20 hour service I told them about this problem and they said these carbs are set at the factory and can not be adjusted, other than the idle speed. Any info would be greatly appreciated.

Brian Raymond
07-31-2006, 11:42 PM
Matt, your dealer is correct in not being able to adj. the idle air bleed screws. To help with your issue, make sure there is no clearance between the accelerator pump arm and the spring bolt, at w.o.t. with the engine off. You may want to see if the problem can be eliminated by, giving it 1/4 throttle and then to w.o. instead of a full dump. This gives the motor a sec. to build vac. Try this and keep us posted. Brian Raymond

08-01-2006, 04:31 PM

If you do not live in California, then you can adjust the carb, you first have to remove the caps and have access to the bleed screws. Use a small drill bit and drill holes into the caps then pop them out with needle nose pliars, then close the screws all the way, open each up 1-1/4 to 1-1/2 turn and see how it is then...... This adjustment is usually for rpm at idle and puttering speeds, but if what Brian suggested does not work then I would try this. You may also have to adjust he idle screw. Do not get the rpm too high at idle as you will cause the transmission to engage too hard.

Im not sure if it is Indmar or SC that chose this CA emmissions thing, but it has to be the dumbest standard feature ever put on a boat. Let me guess: Al Gore has a 310 Carbed Moomba.

I had Idle problems and hesitation problems, performed this little surgery in 20 minutes and have not had carb trouble since. As I always state on this subject matter, since it comes up a lot, next year when mine is out of warranty I will get rid of the Holley 5150 P.O.S. and replace it with the proper marine grade 4 barrel Carb: Holley 4160. $500.00 at www.skidim.com

08-01-2006, 07:55 PM
Thanks for all the help guys. My boat runs fine if I give it a little throttle before dumping it into full throttle. I may try turning the airscrews, but it doesnt seem necessary at this time. If I adjust the airscrews will this effect my warranty?

Brian Raymond
08-01-2006, 11:27 PM
Great to hear your up and running. The cap-offs on the idle air screws came about from a calif. gig. It will void your warr. if your carb should ever have to be replaced, and the caps are missing. I started thinking (I hate when I do that), that you can have up to .010 clearance on the acc. pump arm and the spring bolt with eng. off at w.o.t. Brian Raymond

08-02-2006, 08:40 AM
The email I got from Indmar on this specically states that my warranty will not be void as a result of removing the caps. I keep several copies in the event I should ever need it, as well, I ski with an ambulance chasing attorney. The manual states that the warranty may be void if you remove the caps; therefore, that was my insurance I obtained before I did it. If you decide you need to adjust them in the future I would contact Indmar and see if you could get them to authorize this.

If there was no need for these screws or no purpose then they would not be on the carb to begin with, instead there would be a permanet set point device thingy. So one has to ask how could the use of a standard feature affect warranty? Its nothing short of rediculous.

Anyone else ever adjusted these screws and had much better performance?

08-02-2006, 01:02 PM
I was having all kinds of engine problems at slow speeds and idle until I adjusted mine. Now you can barely tell the difference between this boat and an EFI engine. Runs great. I live at 4700 feet and often operate the boat at 6200 feet.

08-02-2006, 01:57 PM
Exactly my point. Running rough would probably do more damage than smooth, but then again Im no rocket mechanic.

08-02-2006, 04:26 PM
Any chnace you could post a few pics for those of us who are less mechanically inclined? Where exactly are the "caps" and where should the holes be drilled to remove the cover?

My '06 LSV carb is a huge dissapointment. I knew I wanted the EFI when I bought the boat but I also had some real specific "needs" when it came to color scheme and options. Our dealer had the exact boat that I wanted except for the carb. I've never waited for anything so ordering a different boat never even occurred to me. Now, every time I sit on the ramp listening to my starter crank for about 3 min straight, I start thinking that maybe the color of the boat wasn't that important.

At any rate, after 4 separate services with the dealer, they are telling me that "the carb cannot be adjusted any more." I'd love to get in there and try the adjustment you're talking about. I also like the idea of upgrading the carb but my pregnant wife is already threatening to divorce me and my boat if I spend another dollar on it.

Thanks for the great info.

08-02-2006, 05:04 PM
I have printed pictures somewhere, too bad this thing wont let me draw. I have changed jobs since I had the pictures on the computer and therefore do not have them. Lets assume then that the bow is north and the platform is south. Take the fire helmut looking cover off and looking at the east and west sides where the carb mounts about 1/3 of the way up from the top of the engine, at connection, on the "throat" (for lack of a better term) you will see 1 cap on each side closest to the north end of the boat. These caps look like leather furniture tacks. They are the same color etc. and are smaller than a dime in diameter but not much smaller. They are closer to the engine than the flame arrestor screen.

Be careful when drilling, use a small bit (i think i used smaller than 1/8 )and there is only the need to make a hole, take your time. You dont want to drill to deep and hit screws which may cause damage.

If I can locate the pictures I will get them scanned and posted, otherwise follow my little map and they should be obvious.

After you have access to the screws you will need a sunglass repair type flat head screw driver, which I think everyone has in there junk drawer. Finally, a use for this token of love from the aunt who drew your name at Christmas.

08-02-2006, 06:43 PM
325 EFI and tandem trailer were my only absolute necessities. After reading many posts about trailer and cab issues I think I had my priorities straight.

Ed - You crack me up. I never knew that I needed a whistling in my pants when I walk. Thanks for enlightening me, I'll let you know how it works out. :p


08-02-2006, 07:19 PM
Ed, I tried the foreskin thing and it only works if you wear boxers. I asked God for a new foreskin but He said that I voided my warranty. You were right after all.

As for the carb - should I just accept the fact that my $50K boat is going to run like s%*t for the next couple of years until I can finally get in there and make the adjustments that have proven to make it better when the warranty is up? I've been to the dealer 4 times now and they tell me that nothing more can be done. In this case, the dealership and probably even Brian are restricted in what they can do or tell me to do because of the great Republic of California, et.al. Adjusting the air bleed screw will effect the emmissions and SC cannot recommend anything that negatively effects emmissions. Holley wouldn't have put adjustment screws on the carb if they weren't meant to be adjusted - even if only in extreme cases.

Admit it, if God put adjustment screws on your foreskin, you'd be awefully tempted to tweak them to see if you could get better performance.:p

08-03-2006, 11:03 AM
Sorry If I was unclear in previous messages. SC, I thought, warranties the boat, Indmar warranties the engine, its possible I am wrong on that. However, as I stated in previous thread of this post, I obtained written permission from Indmar to do the drilling adjustment. I also suggest anyone wanting to make these changes to their engines do the same thing prior to beggining the work.

By the way, Carb ajustment vs Foreskin tampering? Humerous indeed but vauge at best when used as an analogy for the subject.

08-03-2006, 12:01 PM
Ed, Im just a smart ass by genetic deficiency. Hopefully my analogy statement was received by you only as added humor to your humor.

I have thought about mentioning the name of my contact from two years ago but I fear he might get in trouble if the remote possiblity exists that he told me in writing, incorrectly. I suppose I am being rather greedy with my Indmar email in protecting myself. I can only imagine how upset the elite at Indmar would be if 200 people drilled all the way into the carb itself as a result of this post and they had the name of the man that said we could do it.

Also I want to clear up with anyone considering this that I have done it myself, I had instructions from Indmar, basic supervision from PCM (I live 10 min from PCM and ski with them regularly). It works, but do your homework aside from these postings.

Engine Nut
08-05-2006, 09:28 AM
Originally posted by Ed G

Hey Yella, yes indeedy I understood the humour.

I have contacted Indmar and asked them to check out this thread and perhaps offer some input. Hopefully they will.

Be nice if they could direct us all to a service bulletin describing the procedure (with illustrations) - if one exists.

Thanks for the input.


The caps are covering the idle mixture screws to satisfy the rules of the California Air Resources board. If you do not live in california, removing the caps and tweaking the idle is not illegal.

As far as voiding the Indmar warranty goes, removing the caps should not be an issue. It certainly would have no effect on other engine components which leaves only the warranty on the carb itself.

In actuality, we don't look at the warranty on a carburetor to extend beyond 20 hours in most cases. The thought here is if there is an actual defect in the carburetoe it would show up during the first 20 or so hours. After that, carburetor issues are generally caused by the fuel or the environment the carb is being operated in.

The only problem we have seen from somone drilling out the caps is that in one case somone slipped and drilled through the carburetor body and in another case somone damaged the idle mixture screw. Those were not warrantable situations.

I hope this clarifys this issue. Starting with 2007 Models, there are no more carburetors and I for one am extremely happy about it and know Brian Raymond is too!!!

Engine Nut
Indmar Marine Engines

08-06-2006, 04:05 AM
Well,...there ya go

Engine Nut
08-06-2006, 08:52 AM
Originally posted by Ed G

thank you engine nut, but one more favor would be greatly appreciated....

Would you please edit your post giving us your name, position at Indmar and contact info at Indmar... for the record.

"Yer honor, whatya mean it's not reliable expert testimony?? "Engine Nut" gave us the info on the internet. You can't dispute that!!". :)

I guess I can do that. My name is Larry Engelbert and I am the Director of Customer Service for Indmar Marine Engines. I'm the guy that makes the rules and decides what is warranty and what isn't among other things. Brian Raymond will vouch for me if you don't believe me.

Engine Nut

08-06-2006, 12:48 PM
Jeez Ed - don't go scaring away the pro's because they want to have a little anonimity !


08-07-2006, 08:33 AM
How Ironic, Larry is the name of the contact I had too. Wow, what a small world.

08-11-2006, 10:35 PM
How many turns I am supposed to turn the screws out? I live at 1500 ft. if that helps any. Thanks-Matt

08-12-2006, 10:07 AM
Start with 1-1/2 to 2-1/2. You may need to tweak that, but it'll b a good starting point
Hope this helps