My 86 is dead......
 

ok guys....as of recently my 86 died on me...im sick of working on it and going 3 steps forward and 6 back.

I recently put new points on it (about 2 weeks ago) and after fooling around with them to get it to start she ran great but wouldnt go over half throttle, so i had a brand new carb and stuck it on there and she reved all the way up no problem but spitted WOT. Well today i went to go cut a tree in the yard and hauling a small trailer behind it she didnt want to pull a hill at all. Im starting to wonder whats going on now...

1. replaced the points again
2. replaced the S/G (better safe than sorry)
3. replaced the carb.
4. replaced the battery (3 times now)

Ive adjusted the points alot and back fires hard threw the carb but only when you pull the choke on or have it on idle.

Reset the carb back to stock settings so i can elimate problems there.

charged the battery so i know its hot and ready

Now its in the shop tore down to just a block in the frame (kind of), i pulled the head off to see if it the exhaust valve is opening with the ACR (its not) so i adjusted the exhaust valve to compensate for that since the PO had it like that and now its worse.... :(

Any ideas? heard it might be the mechanical timing but i doubt it. Could the ACR be shot? If the ACR is shot will another cam from another motor work or no? I believe my motor is a 14HP by the bore and stroke (have had it down before for oil pan issues) i have a 12HP that has a broke piston but cam is good...I really need help with this guys...my 86 is the work horse here and NEED her by spring cuz i have alot of jobs lined up....really dont want to use my 1650 for plowing and blading since i mow with it and hate pulling the mule drive and deck out from under it.

None of the above.

I seriously doubt it

The 86 rolled out of the Factory with a 8 HP Kohler. Now someone could have replaced that with something else.

:bigthink:

Sounds to me, you you could have a Carb adjustment issue (since you say it is new), condenser, or timing.

It honestly sounds like the points still need to be set. I wonder, how did you set them? I've been down that road, and setting them just enough to get it to run isn't enough. Long story short (and other people here can explain it better than I can), you need to set your points (gap them) at the right time in your motors revolutions, otherwise it'll sputter and spit and do all kinds of weird things that make you think it's the carb or something else.

Bottom line: get your manual from our technical section and read up on how to set your points properly :beerchug:

R Bedell it wasnt in any of the first 4. and i know it had a 8hp factory, had a 10 when i got it and i put the 14 in it cuz the 10 slung the rod. i tried starting factory on the carb settings and it still popped back hard, new condensor as well even new coil. im just stumped

jimbob...ill try it again but if the points get moved a little bit it stops firing all together but ill dig some...its just made me sick dealing with it for 2 weeks now

Please forgive me for my ignorance, but what about the points plunger? If that were to operate tightly, would that be a consideration? I would tell you to get the thickest set of ear muffs you could find which would take care and fix any noises, but now I'm stumped as well :bigeyes: !

{just kidding, of course!}

If they are new points you may want to consider filing them. Every new set of points I have bought the last few years required a filing to get the tractor to run right. Points plunger is also something to check.

a 12hp cam will work in a 14.
How did you reset the acr?

Three things....

(A) Set the Carb to the settings as stated in the Manual.
(B) With a VOM (or DVM) make sure there is zero ohms resistance between the Condenser case and the battery negative terminal.
(C) Try setting the "point gap" at .018, 016, etc until you find a good running motor.

I agree with Roland. I seriously doubt the ACR is bad. Adjust the valves to the specified setting. You can just barely see the exhaust valve open, as the piston rolls up to TDC.

This thread goes through how to properly set the points.....
http://www.onlycubcadets.net/forum/s...ad.php?t=28271

Also, I might add, that setting the carb to "factory" settings is just a starting point. It has to be adjusted or "fine tuned" from there. It IS NOT a "set it and leave it" setting. While you are going through all that, might as well set/adjust the governor too since you have had the carb off. Anytime you remove and install the carb, you should adjust the governor.

Here is the link to the Kohler manual for that engine. Please download and read through it. If you still have questions, come back and we'll see if we can answer them.

If the tractor is backfiring through the carb, I would suspect a timing issue (sparking when the intake valve is still open) or the intake valve is not closing fully, allowing combustion back through the intake path.

Take the valve cover off (rectangular cover next to the carb) and watch the valve stems operate while you crank over the engine. Pay attention to be sure the intake valve (on the right) closes everytime. When the valve is closed, there should be a slight clearance between the pushrod and the valve stem--check with a feeler gauge. I think it's supposed to be about .018. Check the manual.

If the intake valve closes fully, then it's time to statically time the engine. Look in the tech section for instructions on how to do this.
http://www.onlycubcadets.net/forum/s...ead.php?t=4405

If it runs at all, it's probably not coil, condenser, grounds, etc. Adjusting the carb from factory settings will improve operation, and, assuming it's clean and working correctly, it should run without backfiring at the factory settings. So that points back to timing and valve adjustment.

An backfire through the intake, or carb can also point to a lean fuel condition.......

I don't believe the ACR is the issue. Once the engine is running the ACR is taken out of the picture because of centrifigul force on the spring and weights. As Roland stated I would try closing up the point gap to.018 or less. If the engine has a lot of mileage on it the point push rod could have significant wear on it or the lobe on the cam could have a groove worn it which will throw the timing off quite a bit. :bigthink:

hey jonathan it wont even start. as soon as it hits compression stroke it pops back

guys yall are a big help but no matter what i do its all still not right.../like i said the PO had the exhaust valve set really tight and the intake in specs...but im gonna try more on this either today or tomorrow

Brandon, try pulling off the spark plug wire so it wont have ignition and crank the engine (with a strong Battery). Does it crank at a nice even pace or does it turn and balk, turn and balk. If its the latter then I agree that something is amok with the ACR (ACR not slightly opening the exhaust valve). If that is the case you might as well go ahead and take care of that first because all the rest is a waste of time until that is right (imo).

I've gotten into the habit of taking a piece of paper and running it through the points while they are closed. seams like they get a little oil residue on them during manufacturing that cause's problems.
few other things to check
sure you have the correct coil?
condenser hooked to the neg side of the coil?
wire on the neg side of the coil goes to the points?
ignition switch is good?
plug wire good? fits snug at the coil and plug?

Ironman it does it with the plug wire off, turns over and stops on compression stroke everytime

Dvogtvpe...everything checks out good but im really leaning toward the acr

Brandon, I've bee down that road with the ACR, and mine popped back through the carb also, although if mine got through the compression stroke enough to start, it ran fine. Here is what I did........on your cam gear there are weights and a very fine hairlike spring. For starting the weights allow the exhaust valve to remain partially open to reduce compression so the starter doesn't have to fight it. As the engine starts rpm's build and centrifical force pivots the weights away from opening the exhaust valve. The before mentioned hairlike spring pulls the weights into position when the engine is not running so that the weights can do their job for starting. It is possible that the spring could be broken, weak, or out of position on the weights. You can view the cam gear, the weights, and the spring by taking the cam gear cover off of the side of the engine, just below the carb. It is very tight quarters, but my spring was out of place and I was able to get it back where it belongs with a wire hook. If you are that lucky that you have same problem and result, then I think you would have to go back and recheck the valve settings again. See this... http://www.kohlerengines.com/onlinec...79.pdf#page=95

I had a spring off also. S/G wouldn't push it past the compression stroke. Hooked the spring back up and was good to go. IIRC I had to remove the oil pan and go through the bottom.

take the head off and check it. then you'll know. instructions are in the manual and it tells you how to adjust it

Even if the ACR is bad, it shouldn't be backfiring through the intake.
If the exhaust valve is or was set too tight, it will hold the valve OPEN not shut. You should have had an exhaust backfire, not an intake backfire.
Did you set the valves to spec with a feeler gauge? Did you set the points with a test light or DVOM? You need to set everything to proper spec. Please set correctly and report back. If you did set to spec, please state that when telling us what you have done.

He said in his opening post that he checked the exhaust valve with the head off and it did not appear to operate correctly by the ACR. He also said he tried cranking the engine with the spark plug wire off and is not getting past the compression stroke. So what do the points have to do with that?? Now as far as with the plug wire on AND a backfire, if you don't get past compression the exhaust valve is not open yet so there is nothing to go out exhaust and backfire. HOWEVER since you have already had intake stroke and compression to a point, ignition occurs just before TDC, but if the ACR is faulty, engine rotation stops, ignited gas reverses engine rotation to a point where the intake valve is open and pop goes the weasel out the carb.

That's my theory and I'm sticken' to it. If I'm wrong (and I have been, many times) I will humbly apologize (and I have, many times).:Bowdown2:

I want to thank yall for all the info yall gave me it helped out alot and well i found my problem was. found the ACR was bent down slightly so i bent it back up and problem solved. i know its a temporary fix but it will start easy now so i can do my garden now. but like i said thanks again....i only have a timing issue now but just wanted to thank everyone again. my 86 lives

it appears there's 2 issues at least. since running over half throttle problem would be more like ign. issue.
just pop the head off. measure the lift at the exhaust and see where the piston is in the bore. check it to the Kohler manual. take the cam cover off and you can bend the ACR tab to get it back in spec . they say not to bend the hardend tabs but I do. worst that can happen is you break it off . if that were to happen you change out the cam. I have yet to break one.
once you get your starting issue fixed then worry about the running issue.

I've found that generally when I get these problem motors in that someone trying to fix it probably created a problem while trying to fix a problem. biggest goof I see is a GM coil instead of a Kohler coil. they both look the same. if you have an ohm meter take all the wires off and ohm it through the + and - terminals. should be 5 ohms. if its 0 you have a coil off a GM or a bad kohler coil.

guess I was slow on my post

Glad you found the problem, and your 86 is running again, Brandon!

X2!:beerchug:

Im still thanking you all for the help....i was pulling my hair out over this. so every bit of info yall passed on is a big help, it will be dearly kept in mind next time i have a problem. my 86 is the mule around my house, from pulling my 16' trailer, breaking plow, and blading...it does more than the others combined. so from this cub lover **THANK YOU ALL** i will help with what i can when asked