cahickm2 Posted March 19, 2007 Share Posted March 19, 2007 Since I am having trouble with the carb on my 3212, I was thinkin about trying a complete different carb. At my dad's house, the previous owner left all of his old equipment. There are at least 10 old briggs motors, all with carbs that resemble the ones on old B1s Like this: However, they are all 8HP motors. What is this difference between these styles and the one peice style? is there a difference between the 8HP and 12HP carbs? the main needle? Link to comment Share on other sites More sharing options...
ehertzfeld Posted March 19, 2007 Share Posted March 19, 2007 The intake are different, but a carb is a carb to an engine. All it cares about that it's getting gas. If you can find an intake and the rod for the governor, it will work. As far as the tolerances between the two, I have no idea, but I'm sure there is a difference. The 4 bolt will most likely allow more fuel and air in than the three bolt. Link to comment Share on other sites More sharing options...
cahickm2 Posted March 19, 2007 Author Share Posted March 19, 2007 when you say intake, do you mean the top of the carb the bolts to the engine housing, or where the air cleaner goes? All of the carbs do have the air cleaner housings, and governor linkages Link to comment Share on other sites More sharing options...
UCD Posted March 19, 2007 Share Posted March 19, 2007 The intake aka intake manifold is the part between the carb and the engine block. Link to comment Share on other sites More sharing options...
HubbardRA Posted March 19, 2007 Share Posted March 19, 2007 I have a 10 Hp engine on one of my tractors. I am running the carb and manifold off of the 7 Hp that was on my 61 Wards from the factory. I had to elongate the bolt holes in the manifold because the holes in the engine were a little wider apart. I also used a gasket that fit the engine. I put it on the manifold and marked the inside hole in the gasket, then ground out the manifold to fit the hole and tapered this hole smoothly into the manifold. That setup runs great and has been on that engine for over 20 years. It still starts and runs great. I also have one of the small carbs on my 713S and it works fine too. Link to comment Share on other sites More sharing options...
MrSteele Posted March 19, 2007 Share Posted March 19, 2007 I have been using a 3.5 HP carb on a 5 HP engine for years, simply because I do not like the unadjustable carbs on late model motors. There may be a small difference in the jet, but I have not noticed a lack of power from starving for gas. If you can make the intakes work, go for it! Link to comment Share on other sites More sharing options...
Kent Posted March 19, 2007 Share Posted March 19, 2007 What you may be limiting with a carb from a lower HP engine is the volume of airflow at high RPM -- i.e. you might be losing a bit of top end power. In return, you may actually be gaining some low end torgue... especially on an engine where the RPM is governed. Smaller venturi = higher torque but lower possible RPM Larger venturi = more RPM & top end HP A lot of people don't realize that it's easy to put too big of a carb on an engine, while putting too small of one is typically not a problem with "driveability" -- just make sure you richen the mixture enough so that you're not running too lean. That'll overheat the engine and perhaps burn exhaust valves... Link to comment Share on other sites More sharing options...
dlcentral Posted March 20, 2007 Share Posted March 20, 2007 On that lil motor it wont make no diff,if it was a racing motor it might but,it aint, adadpt and mount one up. 4 bolters are EXpensive and hard to find anymore. Link to comment Share on other sites More sharing options...
cahickm2 Posted March 20, 2007 Author Share Posted March 20, 2007 how do you tell when the throttle shaft bushings need replaced? and how do you remove the throttle shaft? I reinstalled the carb and attempted to start. I had a flashlight with me and i could see fuel mist coming from the throttle shaft... Link to comment Share on other sites More sharing options...
HubbardRA Posted March 21, 2007 Share Posted March 21, 2007 To remove the throttle shaft, you must remove the two tiny screws that hold the throttle plate to the shaft, then remove the plate and the shaft will slide out. To fix the problem, you will need a new throttle shaft and a bushing to install in the carb where the shaft goes thru. Link to comment Share on other sites More sharing options...
MPH Posted March 21, 2007 Share Posted March 21, 2007 When I was a youngster back on the farm my brother and me made a 3 wheeled push weed eatting mower. Don't remember where we got the spindel but we talked dad into buying a Clinton engine of unknown hp without a carb and a briggs of unknown hp with a rod out the side from the local IH junk pile out back. Made a wood block to adopt the briggs carb to the cliton engine. Used that thing to mow electric fence line out til I left home and dad got 12 bucks for it on the farm sale. Had 24" bike tires on the rear and a half slice of 55 gal drum for a mower shell. OSHA wouldda loved it:p Link to comment Share on other sites More sharing options...
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