B&S won't start

[gbsk]

I have had a lawn mower for about 10 years and it has served me well. i have been unemployed for quite awhile so cannot afford to take it to a repair shop. It is a B & S engine with 3.5 HP and 20 ". Ace is the manufacturer. Model 95902; Type 3107 01; Code 93031605. I hope this is all you need.

I tried to start the mower after I fixed the cable and it would not start. I noticed the throttle did not move when I pulled the throttle lever either way. However, when I took the air filter off, it moved the mechanism with the spring, etc. Do I need to adjust something? I was thinking that the air filter or the screw that holds the cable to the shroud might be jamming the cable somehow. Also as noted below, maybe the spring is too loose on the carb but that would not affect the cable being off or on the shroud.

Last summer I replaced the gasket and diaphragm and cleaned out the carb and the diaphragm and gasket were in bad shape. It worked fine after that. This year, I did not replace the gasket and diaphragm. They both looked in great shape. There was just a slight bulge where the spring hits the diaphragm. I looked at a few videos this year when i cleaned the carb, air filter and gas tank using spray carb cleaner. I cleaned every orifice I found and wiped them well. I have only used the mower about 5 times since I replaced them. I know it has good compression because a small engine repairman said it did when asking about another mower. I took apart the starter assembly and put it back together using tranny fluid as lubricant for the spring. It pulls fine now but will not start. I know the bulb is okay since it squirts gas into the carb when pushing it. Last year I knew something was wrong when I pushed the bulb and there was no back pressure so after I replaced the the diaphragm, it worked fine. I always keep it in the shed and out of the weather. I did notice that earlier this year, I would have to pull the cord quite a few times to start it but after starting, it worked fine.

I noticed that the screw that holds the throttle cable to the shroud bit through the cable. I repaired the cable and it seems like it works fine when the cable is not attached to the mower. When I attach the cable to the mower, the throttle does not move the mechanism that moves the spring attached on top of the carburetor. Is there an exact place on the cable where the cable needs to attach to the shroud ? Is there another reason the mower will not start?

Thanks,
GB

 

[EngineMan]

You say that you have good compression, and that you have cleaned out the carb, have you put a small amount of fuel into the spark plug hole or carb to see if it will fire..? try it.
If no spark or very little spark you will need to look at the ignition, that engine has internal breaker points, so you will have to take off the flywheel, first look for any rust on the pole magnet on the flywheel and on the legs of the armature, if any clean off with wet and dry. remove breaker cover and turn over engine (by hand) and better with spark plug removed to see if the points do open, then look for any signs of burning or pitting, and make sure that the small wire is still fitted to the top of the condenser.
If you do need to reset the points they are set at .020" (05mm) and make sure its right..! points set too wide will advance spark timing and will also give kick back when starting, and if they are gapped too close will retard spark timing and decrease engine power.
If you don't have a parts manual for that engine you can look up one over web, if you can't find one PM me with a e-mail address and I'll send it, and any info that you may need to you.

 

[scott47429]

Have you checked to see if your getting spark also try spring some carb cleaner or starting fluid into the carb then see if it will start if not then you may have a spark problem if so then you have a fuel problem if this is a plastic tank mounted carb it probably needs replaced if it don't start then look at the kill switch to see if its working right let us know what you find out

 

[gbsk]

I looked online for the manual but could not find one. I would appreciate it if you would send it to me.
Thank you.

You say that you have good compression, and that you have cleaned out the carb, have you put a small amount of fuel into the spark plug hole or carb to see if it will fire..? try it.
If no spark or very little spark you will need to look at the ignition, that engine has internal breaker points, so you will have to take off the flywheel, first look for any rust on the pole magnet on the flywheel and on the legs of the armature, if any clean off with wet and dry. remove breaker cover and turn over engine (by hand) and better with spark plug removed to see if the points do open, then look for any signs of burning or pitting, and make sure that the small wire is still fitted to the top of the condenser.
If you do need to reset the points they are set at .020" (05mm) and make sure its right..! points set too wide will advance spark timing and will also give kick back when starting, and if they are gapped too close will retard spark timing and decrease engine power.
If you don't have a parts manual for that engine you can look up one over web, if you can't find one PM me with a e-mail address and I'll send it, and any info that you may need to you.

 

[EngineMan]

PM me with e-mail address

 

[gbsk]

My email is greatyoga@yahoo.com.

Thank you.

PM me with e-mail address

 

[EngineMan]

File's have been sent...:thumbsup:

 

[gbsk]

Thanks Tony for sending the parts manual. I did what you said about cleaning the points, Howeve, I took off the flywheel but I do not think this engine has points. I looked at this video. HOW TO ADJUST The Points on 3.5 HP BRIGGS & STRATTON Engine - YouTube It shows in the video that there are 2 screws to take off under the flywheel to expose the condenser and points. It looks like mine is an aluminum base with no screws in it. Here is the information again. Model 95902; Type 3107 01; Code 93031605.I cleaned out the carburetor with carb cleaner. The diaphragm looks good and is a year old. When I press the bulb to inject gas in the carb, it squirts out fine. I put some gas on the end of a spark plug but it still will not start. I don't have any way to spray gas in the carb. It has a new spark plug. It has good compression.

 

[EngineMan]

Is this the one...? make sure you have a spark, also make sure that the stop wire (356) page 7 is in the switch stop (621) and is not going to earth (ground) if you have no spark test the coil.

 

[gbsk]

The numbers correspond. However, it is hard to tell by a diagram. The flywheel guard I have is a grill on the top. The one in the diagram is one that goes around the perimeter. I will try to find out what the stop wire, the switch stop and where the coil are located and get back to you.

Is this the one...? make sure you have a spark, also make sure that the stop wire (356) page 7 is in the switch stop (621) and is not going to earth (ground) if you have no spark test the coil.