# 11 hp ariens B & S engine no spark



## Doc874 (Oct 18, 2008)

Hello. I have a Ariens YT11 ride-on mower and have been trying to get this to the point of running. So far i have gone thru all wires adding new connectors etc where require. I can turn the key and the engine will turn over very well but there is no spark. I have two 11hp engines one of which has points, the engine i put in looks almost identical to the points engine but there are no points under the flywheel so i am thinking someone removed them. My question is, can i use an electronic coil on this unit instead of putting in any points? This particular engine doesn't have the crank plunger like on some i've seen ( little rod that fits into a small hole that rides on the crank ) instead a points plate with condensor fits under the flywheel. If anyone has a diagram of the engine breakdown or shop style repair manual it would be appreciated. Once i get my camera working perhaps i can post pictures. I also have two 8hp engines that look alike and again on one there are the two wires under the flywheel but none on the other. I have pulled the flywheel on the one with wires stickin out and points look great, i will pull flywheel on other 8hp in a couple of days on my days off.


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## k2skier (Sep 30, 2008)

Please post the model and spec numbers of both engines.


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## MrChooks (Apr 19, 2008)

Try the Briggs web site - you should be able to download a parts list / exploded view of your engine which give you a good idea of how all the "lill bitz" go together. The parts list usually gives the various alternatives for the engine range - so once you know your engine model / series number - you shpould be able to see what parts are supposed to be there - and the parts numbers of any bits you new to replace


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## Doc874 (Oct 18, 2008)

Well i was messing around with the mower yesterday and cleaned the rusted areas on the coil where it mounts to the engine and still no spark, i remembered reading here to check for spark with ground wire off so i did and had great spark and the engine runs great although abit smoky and loud at first. When i hook the wire to ground there's no spark. Now i know this is a kill wire and there was another wire from the ignition area under the dash so i joined this with the coils ground wire and now the engine starts and turns off with the key. Now i just need to work on the throttle components because i have no control over engine idle or running speeds. I have done many chainsaws, this is my first ride-on and its proven fustrating and rewarding. I will post engine #'s once i get home today.


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## Doc874 (Oct 18, 2008)

Well here we go again. Was trying to set-up the throttle control so was turning engine on and off then the starter spindle stuck in the flywheel so i get it loose by rotating flywheel by hand back and forth, this worked for abit than it stuck again and now i cannot start the enigne at all, it just quit not like a low battery where it would spin slowly. I checked the wires etc... all is tight. Battery seems to have a good charge in it. I am thinking it is likely the ignition coil ( not the one at the flywheel ) i tried to cross the two small terminals at the side and no spark or anything else. I remember doing this on several cars i had, i'd short the coil at the two small side post on the housing to turn the engine over. Any thoughts? I also believe this is an add on and not original to the lawn tractor, it looks like one that would go on a vehicle.


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## MrChooks (Apr 19, 2008)

:wave:This one is getting complicated - can't understand why there would be an additional coil on the engine - even if it is some aftermarket add on.

Have you tried to revert the engine to the way it was made - in other words - remove the extra coil & just leave the magneto coil in place and see if the engine runs at all.

The stuck starter is another issue - these B&S starters usually have a Bendix drive - so when they get worn or dirty - they can stick and if the Bendix sticks in the engaged position with the engine running - that will almost certainly destroy the starter motor  - so I suggest you take the starter motor off and have a good look at / clean the Bendix drive. Depending on its age - maybe you could look at cleaning its commutator and replacing the brushes - so that you know you have a good functioning starter motor.


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## Doc874 (Oct 18, 2008)

My fault. I am totally new to this but still i know the difference between a coil and a solenoid so my goof :knife:. It was the solenoid that was bad so when it quit the starter cog would get stuck in the flywheel starter gear i relaced it with a new one and the engine turns great now and starts. Still having abit of trouble trying to set the throttle control lever on the side of the engine to where it will idle without konking-out and not over rev with the lever on the fast area. Thanks for all the help i'm sure i'll be back as this thing seems full of gremlins.:wave:


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## MrChooks (Apr 19, 2008)

:wave:No probs- glad to hear you are making progress with the "gremlins"

On the idle running - does your carb have an adjustable idle jet and / or main jet - as these can usually be adjusted to give you a smooth idle - otherwise it may be a tiny bit of muck in the carb jet - so it might be worth the effort to give the carb a good clean out


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## Doc874 (Oct 18, 2008)

Yes i believe it does have an adjustable idle jet and i will try that today. I just got thru putting on the new drive pulley, the belt is tight, the new pulley is the same outer dia: and inner dia: as the old one i removed so not sure why belt is that tight bu maybe its supposed to be that way?::4-dontkno


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## MrChooks (Apr 19, 2008)

:wave:New belts are always a little tight and will stretch a little - but it shouldn't be really really tight - 

So if you are concerned - check you have got the correct replacement belt (nominated length and cross section should be identical to your old one) and also check that it is routed correctly (eg on correct side of any tension pulleys etc)


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## Doc874 (Oct 18, 2008)

Well took the old girl for a ride today a couple of times around the yard, gears seem ok although high-low has to be played with to get it to engage will check for way to adjust it. My problem is that after several engine starts my battery has been drained, now i know this thing has a stator but not sure of hook up to solenoid, and i do not have a 12 volt tester (yet) I may have it hooked incorrectly, i know its a two circuit one because of the black and red wires coming out under the flywheel area. I did hook these up as per the old solenoid when i replaced it, but, still not sure all is good. Anyone with a scehmatic of how to properly connect this stator? I have another engine (8hp) with only one red wire coming out under the flywheel so i know this is a single circuit, i may just replace the whole engine if the stator is bad in the 11 hp.


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## MrChooks (Apr 19, 2008)

:wave: Good to hear you are progressing with the gremlins. 

See if this B&S site below can help you - you need your engine model no. - But you can get a parts list and that might help you figure out what parts of your alternator might be missing and how they go together.

http://www.briggsandstratton.com/ma...e=Illustrated Parts Lists&menu=nav3&subMenu=3


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## MrChooks (Apr 19, 2008)

:wave: OK I did a little research - you are right you have a 2 circuit alternator - One circuit goes to a rectifier for battery charging and the other is AC (un-rectified) and is used for lights. The B&S 2 circuit alternators are actually 2 separate alternators in the one assembly. The red lead is for the DC battery charging circuit and the black lead is unrectified and used for lights.

I think the diode rectifier is inside the connection plug that connects the two (red & black) wires that come from the alternators - so you should have a rectangular plug on the ends of these wires - if not - you are going to have to buy one - as that is where the rectifier is and you will need that to get the DC supply to charge your battery. The other mating side of this plug has a red lead (for battery charging) and a *white *lead (which connects thru the plug to the alternator black lead) - for lights)

It is important that you don't mis-connect these - so make sure you have the correct B&S polarised plugs connected to these leads so that the DC output goes to the battery and the AC output goes to the lights


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## Doc874 (Oct 18, 2008)

Thanks MRCROOKS. The end plug you speak of is not there. The red lead goes to a plug that looks like its for the lights and the black lead is currently hooked to the solenoid (small side post) I was thinking of installing the 8hp engine and when i looked at it, it has a single red lead with the plug (round one) at the wires end. Incidentally the positive lead for the battery is also hooked to the solenoid post that the light plug with red wire from alternator has hooked to it. I am going to need to take a picture of this to try and explain it is difficult. I think a pic will help.


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## MrChooks (Apr 19, 2008)

:wave: Doc 874 - Do you think someone has messed with the wiring set up in the past - I ask because unless the solenoid you speak of is a voltage regulator (in which case it is a small relay that firms part of the battery charging circuit)- I don't think it belongs in the alternator circuit. They (solenoids) are usually in the starter motor circuit. So I would think the red wire should connect to the battery (to charge) and the solenoid should also connect to the battery and the other side should be connected to the starter motor. Another lead from the solenoid should go to the key start switch (to activate the stater solenoid when the key switch is turned).

Can you let me know what the model / series number your engine is - that way we might be able to narrow down the alternator set up as B&S has quite a few different ones.


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## MrChooks (Apr 19, 2008)

:wave:
Doc 874 - see if this helps - sorry the scan is a bit rough - but my scanner wont fit the whole page :sigh: - but the wiring diag and diagnostics shpould put you on the right path

View attachment B&S Dual Circuit Alternator.pdf


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## Doc874 (Oct 18, 2008)

Thank you so much those diagrams "will help greatly". It looks like i need the proper plug on that wire from the altenator, currently it is missing, so i added a straight wire connected to the red (DC) altenator wire and another attached to the black lead from the altenator, otherwise i am to understand it won't work, correct? I'd much rather work on people, that i understand.


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## MrChooks (Apr 19, 2008)

:wave: Doc I think you need the diode / rectifier on the red wire to give you the DC current for the battery charge. Don't connect them together as they are 2 separate circuits and you might damage the stator coils in the alternator. The red goes to the rectifier and then on to the battery The black > white is unrectified AC, and that is for your lights (so you can mow in the dark)

If you are really worried - any auto electrician should be able to help with the wire up - but you will need the diode rectifier / plugs from B&S I think


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## Doc874 (Oct 18, 2008)

Hi again. The 8hp has the red end still attached from the stator so i think it best to go with that one i will try and follow your diagram you sent. I will need the female end for the red wire and there is only one meaning its only a DC circuit. Ill let you know. I do appreciate all your help its invaluable. I have tried to attach a couple of pictures hope it works.


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## MrChooks (Apr 19, 2008)

:wave: Doc - in the end it's your call - but if the mower came with an 11hp engine - I would strongly caution against down powering it to 8hp (man that is a huge drop in power ).

Mower makers have never been overly generous in the power plants they installed in their rigs - so I fear that if you down power to 8 hp on a rig that was designed with an 11hp unit (and probably could have really done with 12hp - 13hp) - the result will be a complete slug:4-thatsba. 

With 8 hp - the unit will likely move OK and probably mow short / light grass - but any grades / hills and/or thick grass will bring the thing to a halt. After all what you are proposing is the equivalent of re-powering a V8 car with a 4 cylinder engine.:sigh:

As I said - it's your call - but having gone this far with what seems like a basically OK 11hp engine and for the want of a little "auto electrical" work - if it were mine - I would concentrate on the 11hp rig


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