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I have recently acquired a wheel horse b111 it was running fine when I first got but two days later it will not start. At first I thought it was the carb as I adjusted it whilst running because it was really rough but after adjusting it to the original factory settings and making sure fuel is getting into the cylinder I discovered that the spark is very weak indeed so weak you cant see it if you hold the plug in the ht lead and only just see it if you put a screw in the ht lead and hold it againsed the block (earthed) On cars I would say it was the points or condenser but would this have them (1979 build date11hp brigs electronic? )If so then is it worth taking it to the garage as it has no cutting deck and I only paid ｣50 for it. any suggestions thanks

If you need to know if it has points with condenser, post up the engine numbers.

Believe engine for that is a B&S 252707 if so no points with condenser, part number 398811 Armature Magneto

Thanks for the reply I have been working on the mower this morning and it does have points and a condenser although that is the model number I have cleaned the points and I am now trying to find out the correct .Do you know if there is a standard gap for these engines

Standard armature air gap is .020. EngineMan will have to convert that to metric, as I'm not a math major.

Rivets said:

Standard armature air gap is .020. EngineMan will have to convert that to metric, as I'm not a math major.

Click to expand...

.020" = 0.5mm

This maybe a little late......but........

Hi thanks for all your help :smile: the points look ok and I have cleaned them and re gaped them but still no luck what is next? can you test the condenser? which would be more likely to be causing the problem the ignition coil or condenser?

If you contacted B&S tech help line with queries including asking what the magneto coil resistances should be – they will say “Sorry but there are no published resistance readings for our ignition coils”
A Mag Coil primary (The wire connected to the points) has a VERY LOW resistance. It is about 1/2 OHM with the engine block as the common point. It is the rare ohmmeter that can tell the difference between the resistance of the coils primary and the ZERO resistance of a closed set of points. You need to also read the resistance of the spark plug wire to engine ground. It should be in the Kohm range. It can be as low as 4 Kohm to as high as 13 Kohms. No reading is normally BAD but not always. At best using a ohmmeter to check a mag coil is better than nothing test BUT there are ISSUES. THE ONLY TRUE TEST OF A MAG COIL IS ON A MAG COIL TESTER.

How to test a condenser. they should measured out at around 0.22 micro Farad

How To Test Lawn Mower Condenser When Troubleshooting Lawn Mower Electrial Problem - YouTube

hi I have tested the condense as best I can but I cannot do it properly as I only have a cheap multi meter without the correct settings. is it possible to buy an electronic ignition upgrade kit?

Best to ask at your local shop, but if it is the B&S 252707 then part number 398811 Armature Magneto is the one fitted to that engine, but you better ask before buying.

Where in Wales are you..?

My B&S is a 252707 Model so if the spark is weak why not replace to coil nd fly wheel and see if that is better. Just my 2 cents

Once again I made a mistake, not enough coffee thisn morning when I posted. Armature air gap should be .010 NOT .020. Sorry about that. I'm surprise that EngineMan didn't catch that.

hi I am around Welsh pool Powys there are two service dealers in the area that I know of that I can try the coil you mentioned is the same replacement as the one I found whilst researching on ebay uk the coil can only be ordered from the us which will cost an additional $19 or ｣12 bringing the total to over ｣30 or around $50 if it is no cheaper in a service dealer should I look into a second hand item? or are these dodgy thank for all the replies

I have just gone over the page nd seen the last two posts missed them sorry the gap is 0.020 as I checked this with briggs and stratton:smile:

Rivets said:

Once again I made a mistake, not enough coffee thisn morning when I posted. Armature air gap should be .010 NOT .020. Sorry about that. I'm surprise that EngineMan didn't catch that.

Click to expand...

Thought we were talking about breaker point gap.....! which is .020" (0.5mm)
Armature air gap is .010" - .014" (0.25 - 0.36mm)

Powys is a little too far just for me to pop up, I am down near Swansea.

Remember its not just the coil, you will also need a flywheel. Keep looking on E-bay for a coil.

thanks for the reply I didn't know you needed a new fly wheel will it not work with the original?

whmtd said:

thanks for the reply I didn't know you needed a new fly wheel will it not work with the original?

Click to expand...

Is yours not fitted to the inside of the flywheel..?

http://www.ebay.co.uk/itm/Briggs-an...wnmower_Parts_Accessories&hash=item2eb0fc41f3

Can you post up all the engine numbers, and any numbers that are on the coil.

Looking in E-bay U.K only....I see that you can still get item 398811 which is the part number for that engine, take a look....!

http://www.ebay.co.uk/sch/i.html?_o..._nkw=briggs+and+stratton+398811+coil&_sacat=0

Im not sure what you mean by is it not fitted insidecthe fly wheel the wire from the coil does go under the flywheel to the condenser and points but I want to take out wll the orignal parts and replace them with electronic ignition by looking at a vidio on youtube this can be done just by swaping the coil for one with electronic ignition is tgis right?

Had a look on Lawn Mower Parts and they seem to be the same part numbers 398811 for your engine, so give them a phone call or e-mail.

Right I have ordered a new electronic coil and spark plug removed the old one and the condenser I will let you know when it arrives :thumbsup: