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briggs twin 20hp will only run with full choke..help please


yesmam's Avatar
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09-03-08, 11:26 PM   #1  
briggs twin 20hp will only run with full choke..help please

Hello to all,
Just got an agway lawn tractor from a yard sale late 90's unit for real cheap. one cylinder had no compression (bad exhaust valve) took it apart and cleaned it up, reseated the valve...voila compression up to high 90's. reajusted the valves to ,010 clearance (hope that was right) and cleaned the 2 coils as they had some small rust deposits from rain water or something.
Here is the problem, the motor starts well but runs only with the choke held wide open, and pops once in a while, like a surge of gas or a backfire..I asume fuel is missing but I dont see any ajustments. has anyone had a similar problem and or can anyone help me run my new toy up and down my lawn...it needs cut..

 
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Airman's Avatar
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09-04-08, 05:59 AM   #2  
Engine brand name, make, model and serial number would aid in advising.

From the description of your problem, I believe the carburetor to be the culprit. I suggest you clean the carburetor and install a carburetor kit. Immersion/dip cleaning is not necessary. Most of the inexpensive aerosol carburetor cleaners sold at auto parts stores will clean most carburetors. Completely disassemble the carburetor and clean every passage, nook and cranny. Use pieces of copper wire to probe and open holes.

Good luck

 
yesmam's Avatar
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09-04-08, 06:17 AM   #3  
thanks airman, I will look into that, I had sprayed a liitle right down the throat and it seemed to get a little better, but not for long...I will get a kit and desassemble/reassemble.

it is a Briggs and Stratton 22hp model twin..the only numbers I found are on the valve cover- model-40777, type-012451, code-99003067g

if thats not it maybe someone can help me get the right numbers, just not sure where to look.

cheers

 
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09-04-08, 07:59 AM   #4  
Take another look at the model and type number I think these are incorrect. You may only need a gasket kit and not a full kit. Full kits often include jets and can be very expensive.

The numbers may be on top of the valve cover.

This document shows locations of model numbers.
http://www.briggsandstratton.com/mai...eltypecode.pdf

 
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09-04-08, 09:11 AM   #5  
I bet the correct model number is 407777 and type is 0124 E1
May have just left a "7" off of model and mistaken the "E" for a 5

If this is the case the carburetor kit is Briggs part # 792455

I did not see a carburetor gasket set listed only the kit, which also shows to be around $30.00, assuming I that the numbers I used for your engine are correct.

 
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09-04-08, 10:05 AM   #6  
Yup you were both right the model is 40777, type 0124e1 and the code was correct.

Ok, solved one problem, got the kit earlier and took it apart and cleaned it up nice (had a clump of ??? at the float pin). back in and she runs very well....the only problem is the idle...way to high...I know there is an ajustment but I will be damned if I can find it...any of you know where it is? figure it should be accessible with a philips style screw...but don't know

thanks for the help

 
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09-04-08, 10:19 AM   #7  
You should find the idle stop screw on the side of the carburetor near where the rod that attaches to the carburetor from the governor. The screw may have a torx head on it I am not sure, access should be from the front of the engine.

Unscrewing (counter clockwise) should decrease the idle speed, while screwing in (clockwise) will increase the idle speed.

 
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09-04-08, 11:08 AM   #8  
yup that was it...thanks 30yeartech....she run very well, when for a boot upp and down the street. sucker is fast.

no I will sharpen blades and change the pto strap....oh last question on this part, is it normal that at 5-6 height blade the pulleys make contact?..never had a riding mower before, figures that the 5-6 (highest) is just for traveling?

thanks a bunch to everybody....my near free tractor and this site just made my week!!

cheers

 
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09-04-08, 11:32 AM   #9  
I am not very familiar with your particular model, but I would think the pulley's should not rub anything in any postion. The deck may not be adjusted or mounted properly.

 
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