[digger70]

Please help

My tractor started backfiring through the carb after mowing for a half hour, just after turning the pto off from mowing. Once cooled down for a bit 10 - 15 mins restarted running normal then back to about running.

This spring replaced all fuel lines, new fuel filter, fuel pump and cleaned tank.

When I took off the air cleaner housing I seen the fuel filter was about empty and look to be breathing fuel back and forth, put the tractor in reserve. opened fuel cap, made no different, in run time.

don't know hours on this tractor, oil level is right on the money, does use some over a mowing, half pint or less.

carb is clean not a spot of junk or white rust. Filter looks very black, bad fuel line??????????????

Going to pull tank to see what comes out, scared. Wondering if a sumabitch dump something in tank.

Thanks John

 

[gzec]

Could be points or condenser. Assuming an 83 has points.

 

[digger70]

Yes it does I have never changed them or play with Adjustments, have replaced the condenser next to the air cleaner once because of wearing a whole in the side of it, Thanks for the feed back, John

 

[deaddeere420]

Run a compression check while its warm and acting up
Rule out a bad valve seat

 

[knottyrope]

bad seat is more often on the p series engines, an 83 would have a B series

Condenser when going bad will fail when hot

 

[wmgeorge]

I would think a bad valve seat would be cold or hot.

 

[deaddeere420]

Knotty
You have a point, I missed that

Bill
When the seats first loosen they ride up and down with the valve. The valve spring pulls them back into place and when the engine block cools the seat is tight again until the block heats up and expands

Hope fully I explained it well enough
Eventually the seat will beat the block back enough that the seat remains loose no matter what temperature of the block

 

[digger70]

Thanks for all the info, will be looking into this today.

I almost want to say that when it started running bad that it sounded a little like someone ringing a bell, but hard to tell.

The tractor doesn't want to start at all went hot not cranking over, like the timing is way off, when cool starts right up.

Thanks again you guy's John

 

[Hammerdown-7]

Hello John
The B-43-G engine had problematic Ignition condensers. There is a sure Cure for it David Kirk engines make an electric control Modual that takes the place of the Failing Ignition condensers. It is called a Point's saver & I have one on my 1983 John Deere 318 that has been there for two year's with no More Ignition issues at all, & it only cost's $28.00 shipped to your door. I would be willing to bet that if your engine has been back firing due to a bad Ignition condenser, that it has ruined the contact area of the Points by Burning or worse Yet Pitting them. I would suggest that you place new point's, Eliminate the Ignition condenser and place the Point's saver modual on your Tractor. The new point's should be gapped @ 0.019" as well I hope this help's, Kurt

http://www.kirkengines.com/index.php#UltimateIgnitionSystem

 

[wmgeorge]

For $28 it would be a good preventative measure anyway. I am assuming most if not all replacement condensers are Made in China, another reason to change over.

 

[digger70]

Good point there on China.

 

[Hammerdown-7]

Hello John
I have been running my David Kirk Point's saver Modulo for well over two year's now with no More Ignition's issues what so ever. I was replacing the cheap China condenser's twice a summer back when I ran them. It was explained to me that the reason the condenser's Fail so often is due to the massive spark that these Onan engine's produce as the condenser's have to absorb the Wasted spark so that's why they fail. David Kirk also sell's a high voltage coil, but in my eye's the Factory Onan coil is hotter yet than anything out there available so I stayed with it.



I did buy a Like new set of spark Plug wires from forum Onan Expert Boomer, who is Robert Kummer as mine were old and tired and they will Tank as well as they have a resistor on the end of the plug wire just before the spark plug Boot. Boomer has Lot's of NOS or slightly used Onan engine part's to offer at Very reasonable Price's so I would suggest that he be your go to Guy when you need Onan parts. He is very honest, Straight forward and send's Part's that show to be better than his descriptions & he even send's the hardware that held them in Place, That is something Onan Part's will Not do. I put new Point's in when I eliminated my Ignition Condenser and it Takes less than 15 Minute's to eliminate and place the new Kirk Point's saver Module. I mounted mine on the Tractor's fire wall with two 1/4-20 bolts. It has a red LED light in it that flicker's when the point's open and close, and you can Time the engine with a light by this LED Light and finding the timing marks on the fly wheel of the engine. I went the simple route & set my new point's as I said, @ 0.019" and all was Good and I have not touched since.I Like the older style Point's on these Onan's over having the later made electronic ignition system as they are out in the open and easy to service, where as if the later made electronic Ignition Tank's, the engine must be pulled to service it and it is Far more expensive to replace the electronic Ignition parts than a simple set of Ignition Point's are and David Kirk claims that you will get Thousand's of hour's out of one point's set if his Point's saver is used on an Onan engine




Once the David Kirk Engine's Point's saver was installed on my fire wall and I cranked up my Onan P-218 engine The very first thing that I noticed is that the engine start's a Lot quicker, Run's a Lot smoother , and it does allow the engine to have More power. With this in Place now, I was able to Jump up Two heat ranges on my spark plugs as well as gap them now to 0.032" Instead of Onan's suggestion of 0.025" and it has cut down considerably on my over all gas consumption and cleaned up the rich Gas mixture that these Niki Carburetor's cause, and we can't seem to lean them down enough with their main jetting. Over a period of time, These Point's saver's will pay for them selves in Gas cost and Condenser replacement cost so it was a No brainer for me to get and use one with my Brand new engine that I Placed when I restored my 1983 John Deere 318 a couple of Year's ago. I hope this help's, Kurt

 

[wmgeorge]

It was explained to me that the reason the condenser's Fail so often is due to the massive spark that these Onan engine's produce as the condenser's have to absorb the Wasted spark so that's why they fail.

There is no Wasted spark absorbed by the condenser, the JD ignition is no different than the ones used on millions of motorcycles and snowmobiles. That spark fires in exhaust stroke of the engine cycle. The JD coil is no different than what is used on other large engines. Its called cheap production moved overseas for the condensers. I'd bet the ones that came on the Onan engine that were Made in USA lasted for 20 years.

 

[dhager4692]

I was always taught that the condenser acts like a shock absorber in the primary circuit of the ignition.

So as Bill George says "There is no Wasted spark absorbed by the condenser", he would be correct. The spark is in the secondary circuit which has no connection to the condenser. The primary and secondary systems run parallel.

 

[dr_evil]

Bill George said, "I'd bet the ones that came on the Onan engine that were made in the USA lasted for 20 yrs."

Back 40-50 yrs ago when everything had points/condensor ignition, the OEM's recommended replacing them every 350 operating hours or 10,000 miles. And it wasn't unusual to s-t-r-e-t-c-h those intervals. I think Dad probably went 500-600 hrs on his one chore tractor and it still started and ran fine.

Kohler or Onan makes no difference. I had the condensor fail in 125 hrs on a K321 and the condensor failed on my B48G Onan at 160 hrs. And I always replace points when I do a condensor.

 

[digger70]

Thanks for all the info, will be looking into this weekend. Working like a dog since problem occurred, weekend off, John

 

[raboley]

Fought the same issue in a 318 recently. Turned out it was a bad condenser, but it acted like it was a fuel issue.

 

[7dad34]

I'm with Kurt on this. Get the Points Saver and be happy for a long time ! I just gave one to my Nephew-in-law for a 318 I restored for him. same issues and problems. Installed the PS and it runs like a top.

 

[digger70]

No spark period, Replaced Points and those where totally shot. Condenser was also changed, still nothing?

 

[digger70]

Just found the Problem TCM had one from the 316 plug and BAM it runs, One Happy Boy