QuestionQUESTION: I have a Craftsman 6.0 hp with B&S engine. Model is 917.388391. When running it revs itself. I took the cowel off and discovered that the governor link is pulling the carb open and shut. The governer spring is in place. Before diving in, I'm trying to determine if the fuel supply is sputtering, causing the governor link to do this or if the governor itself is the cause. I can't see the governor without a whole lot more disassembly, so I thought I'd ask first. Thanks!
ANSWER: Hello Mark:
Im Glad you Stopped where you were. The Governor Itself is Not the Cause of the Problem. You can View a Breakdow/IPL of the Engine and Carburetor at this Addy http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0& and Enter the Model Numbers 12H802 and the Type Numbers 2675 (this is the Model and Type Numbers of your Engine) and Click Search. Then Select View PDF. Remove, Disassemble and Soak the Carburetor Overnight and then Blow Out the Passages with Compressed Air. Install New Kit. From the Quick Glance I Took of the Breakdown/IPL, Im Including the Instructions for Setting the Air Mixture Screws. **The High Air Mixture Screw is In the Carburetor Bowl in the Center of the Nut or Some Carburetors have Both the Low and High Side by Side on the Top Side of the Carburetor. The Screw Closest to the Engine Is Usually the High Air Mixture Screw on this Type Carburetor.The Low Air Mixture is the One at Top on the Side and Goes Into the Carburetor. Some have the Idle Air Mixture Screw Going Vertically Into the Top of the Carburetor. The Idle Screw is the One that Moves the Throttle Plate. The Following is the Directions for Setting these Screws. **If the Carburetor was Soaked Overnight in Carburetor Cleaning Solution and the Passages Blown Out with Compressed Air and a New Kit Installed, then we can Set the Air Mixture Screws. Turn Both Air Mixture Screws In Until Seated. **DO NOT JAM SNUG ONLY** Turn Both Screws Out 1 1/2 Turns. Set the Throttle to Full Open and Start the Engine. Override the Throttle by Pushing the Governor Arm by Hand and Turn the High Air Mixture Screw(bottom of the bowl) In Until the Engine is Revving Properly. Now Slow Engine to Idle. Set the Low Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle. Now Set the Idle if Required.** Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Thanks very much John.
I did rebuild the carb, cleaned it and sprayed all orafices with compressed air. That seemed to do the trick -- after I put the right gasket in ;-) The only problem is that after running for about 30 minutes, it was up to its old throbbing tricks, though not as severe. I'm going to refill with fresh gas. One thing I neglected to do is replace the Welch cap. Will that matter? Any other suggestions? BTW, there are no adjustment screws in the thing.
Answer Hello Mark:
You have the Non Adjustable Carburetors. I Hate them. The Carburetor Didn't get Clean All the Way. You can Try some Carburetor Cleaner Gas Additive and See if it Cleans it Out. If it Doesn't, then You can Purchase a New Carburetor for Approx. $30.00 to $40.00. With the Adjustable Carburetors you can Adjust for the Slight Restriction; Not So with the One you are Working on. I have Cleaned these Type of Carburetors as Many as 4 Times and Ended Up Replacing the Carburetor. Glad I Could be of Assistance. You are Very Welcome and Contact me Anytime you Feel the Need. May All your Mechanical Problems be SMALL ONES and May the All Mighty Bless You and Yours. Till Next Time.
Best Wishes and Good Luck
Respectfully
John
