This sucker should run..

Anonymous-0

Well-known Member
Hi. I've been posting in here this week about a 8n that i bought but it has it's troubles and i'm trying to take care of them 1 by 1 .. the biggest problem i have right now is that i can't get this beast to run. it has sat up for a long time and yes the tank and carb were a mess but i steam the tank out and brought the carb to work and glass beaded that out and soaked it in carb solution for a day. the fuel in the settlement bowl on the tank now looks clear and the carb looks clean everytime i take it a part. i have put new plugs, points condenser, dist. cap , rotor button, and spark plug wires but still can't get it to run on it's own . i even did a compression test on the engine to make sure i had someting to work with but it seemed to be ok. all cylinders on average had right around 90psi. and when i crank the engine and put my hand over the carb with it cranking it seems to pull on my hand from the suction from the carb when i crank it but no gas comes out of the carb like it should when i take my hand away from it. but when i take the drain plug out of the bottom of the carb, gas always runs out of it. so i know the carb bowl has fuel in it and it seems to have the suction but won't pull the gas out of the bowl. i got a friend of mine to pull me down the road slow in 4th gear and with the breather tube disconnected from the carb if i shoot carb cleaner in the throat of the carb while being pulled it will run as long as i keep the carb cleaner to it.. it has the marvel type cab with 2 screw adjustments on it. i,m pretty sure the smaller of the 2 adjusting screws is a low speed adjustment but is the bigger of the two adjusting screws a high speed adjustment and could i have it screwed to far in not allowing it to get the fuel it needs??... getting pretty desperate not knowing else what to do...i've not worked on that many of the 8n's with a flat head engine that i couldn't get running but this 1 has got me stumpped.. the serial # on the left side of the engine block looks like it was stamped in there but it's been around so long that it is wore off just enough that i can read it so i really don't know exactly for sure what one of the 3 carbs that i think would of came on these tractor i should have. but if i have good compression which is about 90 psi and good spark and gas shouldn't this sucker run?...it seems like a fuel problem because if i pull her down the road and hold the carb cleaner to her it will run but if i crank on the engine with my hand over the carb it will not run any gas out of the throat of the carb...thanks for any help ya'll can give me..
 
" i can't get this beast to run"

For those of us w/ CRS.....you need to ID the "beast".

Front or side distributor, 6v or 12v?

" i,m pretty sure the smaller of the 2 adjusting screws is a low speed adjustment"

I'll assume by that comment that you do not have a manual for the tractor, correct?

Do you have a multi-meter?
75 Tips
 


Seems odd that it wants to run with the starting fluid but not gas - have you checked that the manifold is not warped or sucking air? When you steam cleaned out the tank did you let it dry out completely? Wondering if water is getting into the carb. My guess is that air mixture is wrong and that maybe by bead blasting out the inside of the carb you got some gunk in one of the jets - as you will be told there are some hidden little orifi that only need a tiny bit of crud to block them off.
Do you have access to another carb from a tractor you know runs? Might want to swap it out and see if that makes any difference. Good luck and be patient - not sure if you want to have it running with just starting fluid for too long though.

Lee
 
Think your diagnosis of a fuel problem is correct based on the fact that it will run if you spray carb cleaner in the throat. Something in the carb is not clean. Need to soak it again and run wires thru all the passages. Beginning adjustment of the needles is 2 turns on on the main (down pointing) needle and 1 turn out on the idle screw.
 
As has been said, some passage(s) stopped up. Notice that both Idle and Power fuel pass through the Power Adjust needle/seat as well as main power jet found under the nozzle. Seating the Main Power Adjust will completely shut off ALL fuel into the engine.
 
That should tell you the carberator is plugged.I used a pump oiler filled with gasoline to start Model A Fords in the 50s.They had a updraft carb.No need to tow,Thats dangerous.Over choked updraft carbs will drip gas.
 

you're probaly right but every hole i can find inside the carb, i take the little red tube that comes with the carb cleaner and if i shoot it in a hole i make sure it comes out a hole to be sure the passage way is clear.
thanks
 
yea you're right but when things start to get the best of me sometimes i do some not to smart stuff like that to try to get over that stump. :-)
 
it sure seems like something wrong with the carb to me but every hole i find to stick the little red carb cleaning fluid tube in seems to come out of a hole but i really do think there is something somewhere in the carb that is plugged.
thanks
 
thanks a lot. this really helps me understand and
see where all the passage ways should go all the
way through and where it could be plugged.
thanks
 
that would be great if i could find a carb to try
but the only ones i can find for nowis the ones at
the tractor supply store for $200 and i wouldn't
mind spending the money if i knew for sure that was
my problem. do you know if all the 8n's have the
same carbs or do they have diffrent carbs for
diffrent year tractors.
thanks
 
i thought i did i.d. the beast as a 8n and it has a side mounted distributor. it's been converted to 12 volts and no i don't have a manual for the tractor but yes i have a multi meter
thanks for the tips,they are helpful
 
(quoted from post at 22:54:56 07/19/13) it sure seems like something wrong with the carb to me but every hole i find to stick the little red carb cleaning fluid tube in seems to come out of a hole but i really do think there is something somewhere in the carb that is plugged.
thanks
Skip "the little red carb cleaning fluid tube" and run a piece of small
wire through them per the diagram. That type of cleaning has bit me before.
 


Just how urgently do you need the tractor to get going? You may wish to send it off to GB in MT for an overhaul it will come back like new.

Lee
 
(quoted from post at 07:33:58 07/20/13) Sounds to me like a stuck needle, had that issue after I rebuilt my carb.
ot according to this statement of his, " but when i take the drain plug out of the bottom of the carb, gas always runs out of it.". But it would be more certain if he said it runs out long enough to fill a pint jar in 2 minutes or less. Otherwise he may just be draining contents of carb bowl vs showing that real flow from tank, through carb, needle/seat is established.
 
thanks. thast an ideal but i think i can get a new
one off the internet for about $120 and thats what
i'd probally have in it if i sent it off..thanks
though
 
you're right. maybe not getting the hard stuff but
ust pushing enough carb cleaner thru there to think
that it's clear..
thanks
 
(quoted from post at 12:29:43 07/20/13) thanks. thast an ideal but i think i can get a new
one off the internet for about $120 and thats what
i'd probally have in it if i sent it off..thanks
though
But.......you'd have a quality original that has already been proven to
last 65+ years, not a foreign made repop that might not last 10 years.
 
ok. will try to remove the bowl plug and see if it
fills a pint in 2 minutes or less. good to know how
to check to see if i have the right amount of flow.
but if the bowl is filling after sitting shouln't it
run at least long enough to empty the bowl?
thanks
 
but i am getting fuel in the bowl...the needle doesn't look that hot though. it doesn't over flow gas out of the throat but the needle tip has steel showing around it, also has like a ring of rubber around it.. does that sound right to you how this needle looks? never seen one like it. i'll be glad to replace anything it needs after i hear it run and make sure shes worth it...
thanks
 
(quoted from post at 12:39:29 07/20/13) ok. will try to remove the bowl plug and see if it
fills a pint in 2 minutes or less. good to know how
to check to see if i have the right amount of flow.
but if the bowl is filling after sitting shouln't it
run at least long enough to empty the bowl?
thanks
es, about one to two minutes. Needle sounds like normal neoprene tip type
 
You are correct in finding the fuel problem. Take the carburetor off, remove the bowl, get a small piece if wire(loaf of bread wrappers work for me), run wire through every hole you see in the carb. Top and bottom. remove adjustment pins when you do this.
When done, use a compressor to blow debris out of carb. Replace adjustment pins and set them at 1 1/2 turns out. Put carb back on and start. Once started, adjust carb pins as needed, not to exceed 1/4 turn at a time. Hope this helps.
 

With this much trouble I'd do a complete re-build of the carb.

Get a kit and a clean place to work. Take her all apart, including the jets (be careful and don't strip them out or you will have more problesm!). Soak the body for a day or so, blow and wire out the passages, put your jets back in (making sure they are clear). Upon Gary's advice I don't use the ones in the kit unless yours are really messed up and the ones in the kit are the right size. Reassemble with the new shafts (yes, they can suck air around them and cause lots of problems). Make sure the float actually floats, is adjusted right (1/4 inch if I recall) and the needle valve moves freely. I'm sure Gary (GB in MT) would help you if needed, we talked on the phone while I was rebuilding the one on my 9N (had weird packing around the throttle shaft). I'm sure there is something I missed saying but this is the general procedure.

Unless you are lucky there really is no quicky way to get at the carb problem without doing it right. I rebuilt two carbs last year and it made a world of difference in both tractors. Good luck!
 
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