low power

[RDH]

i responded to the "8n just doesnt have the power" and i wanted to verify with someone that the single wire coming from the distribter is running back to the rectifier is this right? it works ok but like Thommoos said it really doesnt seem to have the power it should i replaced almost everything and seems to run the same.

 

[Bruce (VA)]

We need some more info about your tractor.

When you ask a question here, it’s always important to tell us:

1. The model of your tractor (2N, 9N, 8N, NAA, etc).

2. If it is 6v or 12v.

3. If it’s an N, if the distributor is on the front or side of the engine.

4. If it has any major parts that are not OEM, such as electronic ignition, an in-line fuel filter, a Zenith carb, an 8v battery, a side coil on a front distributor, etc.

Troubleshooting is different depending on the model of the tractor, voltage, ignition system & distributor placement & the absence of OEM parts.

It doesn't have a rectifier. It might have a resistor though.
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[lha]

I don't know that the N series have a rectifier,as those are voltage limiting devises.If you're talking about a resistor,then the answer is yes,depending upon model,how it's set up,6v,12v,converted to E/I? The wire actually goes to the dist,rather than from it,since the wire must carry current to,rather than from the dist.I would investigate a problem concerning the amount of current,that is to say amps to your dist.Hope that helps.---lha

 

[lha]

Dang,Bruce,You're not only smart,but a faster typist than I am[which isn't saying much].I hunt and peck,and my fingers are not only twisted,but cover two keys at once:]---lha

 

[Gramps in NM]

Whoa!! My 51 8N side mount, 12V has a rectifier or diode if you wish. I also see numerous conversion drawings with same included, I think in the alternator circuit. so what gives here?
thanks for clarity.

 

[RDH]

as far as i know its an 8N it has the front mount dist and yes its a resister that the wire runs from it is converted to a 12 volt and i added an inline fuel filter but appears to have plenty of fuel flo. I installed a new Marvel carb i have changed plugs (to Bosch), wires, dist cap and rotor button and when i travel up a hill in 3rd gear it will slow down and quit if i dont gear down that is with the throttle wide open.

 

[jclus]

Govenor??

 

[Bruce (VA)]

His question referred to a rectifier in the ignition circuit. My response was overly broad & directed only to a rectifier in the ignition circuit. As it turns out, he probably has both a rectifier and a resistor on the tractor as it is a 12v frontmount. The resistor is in the ignition circuit & if it as an alternator instead of a generator, the rectifier is in the charging circuit.

And you must be as old as me to call it a rectifier instead of a diode!
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[Bruce (VA)]

I don't know about smart, but I double my typing speed by using two fingers!

 

[Bruce (VA)]

Telling us you have Bosch plugs is no different than telling us you have Champions or Autolite. The brand doesn't make a difference; is the model number that counts. There is, for example, a difference in performance between Champion H-10 & H-12's. (see tip # 7) Your Bosch plugs could be just fine or they could be the source of your problem.

There are many reasons why it has poor performance. Start by troubleshooting the problem in a systematic manner, working from most likely to least likely and easy to check to difficult/expensive to check. Replacing parts is an option but is always expensive & seldom works.

First, find out if the plugs have the correct heat range for the tractor.

Next, you say you added an in-line filter. Why? The N has 3 fuel screens which are more than adequate if you keep them clean.....unless the tank is full of rust. If it is, you will be replacing that in-line filter pretty often.

Check for fuel flow. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. Let it run for at least 30 seconds. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related.

There are three ways to check to check the operation of the governor. Get the throttle lever at it's lowest point (engine ideling) Then, start tapping the throttle lever slowly open. How far does the throttle move before the engine speeds up? Lack of low speed throttle response (like about 1/3 of the throttle) is the classic symptom of a bad or out of adjustment governor. Next test, put it in gear at about 1/4 throttle, put your foot on both brakes & let the clutch out. The engine should throttle up as the governor arm opens the throttle plate in the carb to compensate for the load on the engine. Next test, w/ the tractor running, pull on the rod going to the carb; does the governor pull back? If that does not work, get out the I&T FO4 manual & check out the 'adjusting governor' paragraph. Finally, before I paid $200 or more for a governor, I'd pull it off & open it up. It could just need new balls & races.


There are number of other things you can check, but these tests are the easiest & cheapest given the symptoms you described. Post back w/ results or other questions.
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[Colin King]

RDH,

The conventional wisdom on the board is that these tractors don"t like an inline fuel filter (and are unnecessary if all of your OEM filter screens are in place and well maintained) and that the sparkies that perform best are the Autolite 437 plugs.

Have you checked fuel flow out of the bottom of the carb? It should be a steady stream of gas.

Colin, MN

 

[Colin King]

Bruce, You are always a font of information! Thank you for your contributions to the board.

Colin

 

[RDH]

thanks very much i have wondered about the governor because the linkage is very sloppy around it and i do have to throttle over a 1/4 of the way before the engine increases its idle but its something i know little about i will investigate that over the weekend and post back. I see these balls you speak of on ebay for sale reasonably priced (i think) if that is what it needs. I will be needing the old girl for plowing snow coming soon here in the Canadian maritimes.......possibly Monday!

 

[Bruce (VA)]

Tnx Colin! Kind of you to say so.

 

[RDH]

Bruce i ended up changing the points because i did not have fire on the # 2 cylinder and that certainly made a huge difference but i still think the govenor is a problem i do not have a shop manual but i am ordering one do you or anyone have the adjustment info for the govenor.

thanks
Randy

 

[Bruce (VA)]

Glad to hear it's running better, but the points didn't help it get fire on #2. Points effect all 4 cylinders equally.

Look at the distributor cap; if the #2 nipple is cracked or broken, that's the reason #2 isn't firing. And, if it is broken, it's because your pivot pin is worn out & the axle is hitting the cap.

If the governor linkage arms move back & forth, balls & races won't fix that. I'd pull it off & send it to nnalert's for a rebuild.
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[RDH]

i did change the dist cap as well so that may have been the problem all along but the points were not right to begin with since i got the new points set right its never run so good. i am ordering a manual i believe you said to order the IT Shop manual is that right?

thanks
Randy

 

[Bruce (VA)]

Yea, the I&T FO4 manual is what you need. The Master Parts Catalog is nice to have as well. If this site doesn't have both, I know nnalert's does.
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