View Full Version : 87 Prostar carb issues

08-31-2010, 01:09 AM
Well, yet another problem with the never-ending problems with this boat. Has been nothing but a non stop hassle since we bought it two years ago. Now, there's nothing left to replace, but the carb, which has been worked on a few times, is acting up again. If you knew the whole story, you would understand, but we are at the end. We are completely upside down in this boat, and extremely fed up. So my question is, the boat will run at anything above 800 rpm. Get below that, and it starts sputtering and dies, sometimes with a pretty good backfire. It's an edelbrock carb on there now, and we had a wedge plate put underneath it so it sits level. So here's my questions...

1. What carb is supposed to be on here?
2. Has anyone else ever heard of this leveling plate we were told we needed?
3. Is it worth a rebuild?
4. Is there something simple were missing?

Thanks very much for any help. It's much appreciated.

08-31-2010, 06:11 AM
The edelbrock is not original. You would probably have to talk to a pretty good carburetor guy to know if it is a good match for the boat (there are a lot of variables that can be tweaked with in a carburetor and without knowing how this has been done over the years you might spend a lot of time and money getting it to work the way you want it).

If you are interested in playing with carburetors the Edelbrock might be a fun experiment, but if you are interested in boating I would replace it with the model that is original to the boat.

The original carburetor for an 87Mastercraft is the Holley 4160 (assuming you have the standard 351). If it were me I would get back to the original carburetor that is setup for that engine and a new one can be had from skidim.com for $500 at this link:
http://skidim.com/prodinfo.asp?number=RA052003. In later years Mastercraft / Indmar moved to a different carburetor (the 4100 I think?) that had some problems but for the most part I think the 4160 has a good reputation.

Sorry to hear your boat has been a problem.

08-31-2010, 06:17 AM
From your login and location... do you work for John Deere? I bought a JD zero turn mower this year that has been great. I know it was built somewhere in Wisconsin

08-31-2010, 07:31 AM
I've never heard of a wedge plate before. Once you start to accelerate it's not going to be level anyway.

BTW: I purchased and installed that carb from skidim and it works extremely well. The biggest difference I see between it and my old carb is the great cold start and idle the boat now has.

08-31-2010, 08:24 AM
Has anyone else ever heard of this leveling plate we were told we needed?

My 85 S&S has a leveling plate and i would like to remove it if its not needed.

1985 Skiier
08-31-2010, 10:21 AM
My 85 has the 4160 and runs perfect, no plate. Let's see a picture of the rest of the boat...

08-31-2010, 12:03 PM
My 86 with the original Holley 4160 runs perfect, no plate also. I have rebuilt it twice in the past 24 years for about $50 each time.