1948 8N losing power

[Mark in AL]

Thanks in advance for any help on this. Here's what happened today and the last time I bush-hogged: It cranked up and idled OK, but not great. I was able to bush-hog for about an hour or so, and then it started getting bogged down in the thicker grass. This got gradually worse and worse until it could barely make it up a slight incline with the bush-hog engaged. It would turn the blades OK in idle, or drive OK with the PTO dis-engaged, but not both. By the time I got it back to the house it was even worse, and had a hard time just driving. It sputtered and missed when at mid to high power, but would eventually settle down when pulled back to idle.

It hasn't been running great overall, and I probably need to clean out or rebuild the carburetor, but I was hoping someone might be able to point me to something specific with these symptoms. I was using new gas and have recently changed the points and plugs, but it was acting this way before all of that was done.

Thanks for your help! I'm always grateful for the help you folks provide to us newbies.

Mark in Athens, Alabama

 

[wwildhorse2k]

Hi Mark,
Probably time for a tune up and carb rebuild. but before you do that double check the vent on the gas tank-- mud dobbers love the vent. Check that plug on the bottom of the carb. Remove it and see if you get a half pint in 3-4 minutes. there are 3 screens that filter the fuel check them all. If you just did a tune up with new points the TSC points suck. But it sounds like a fuel problem to me.


HTH

- Mark

 

[Dell (WA)]

Mark.......keep yer itchy-twitchy fingers off'n them handy-dandy carb tweek'ums.

You gotts weak sparkies. It takes about 1-hr fer yer 8N's frontmount squarecan ignition coil to MELT its internal insulative tar. It takes about 4-hrs or overnite to cool-off and you will have good sparkies again. (for about 1-hr) Once the tar melts, it will continue to melt and cause weak sparkies. New squarecan coil is the ONLY fix. Sorry......Dell, yer self-appointed sparkie-meister

 

[lha]

Your local auto parts store has high quality[for today's standards]parts for your machine.Bruce,JMOR and others have put lists on this forum.Search the archives for these lists,but don't buy junk just because they say it will fit your tractor.I recently bought a steering wheel from TSC,brought it home& looked at it ,looked on this site and it was $30 cheaper and looks great!.Get the best parts you can,Blue streak,Napa,I recently got Borg Warner points,cond.at O Reily's,autozone and others have them as well.

 

[lha]

Your local auto parts store has high quality[for today's standards]parts for your machine.Bruce,JMOR and others have put lists on this forum.Search the archives for these lists,but don't buy junk just because they say it will fit your tractor.I recently bought a steering wheel from TSC,brought it home& looked at it ,looked on this site and it was $30 cheaper and looks great!.Get the best parts you can,Blue streak,Napa,I recently got Borg Warner points,cond.at O Reily's,autozone and others have them as well.

 

[Jim in Western MI]

Same thing happened to me once while heavy-duty mowing. Struggled at high power but seemed to go fine with mower off. All it was was one plug fouled with a carbon chip. Simple test..., while fast idling, ground each plug with a screw driver and you can hear the miss or engine rpm decrease. If you get to a plug that grounding doesn't affect, take that plug out and clean or substitue the spare/extra spark plug you always have with you (don't you?)! This was a field repair for me, miles from the shed. Had it back to normal in five minutes. Good luck.

 

[souNdguy]

any time you hit running problems, do a spark test first.. and if that passes with flying colors.. then move on to fuel.

soundguy

 

[Mark in AL]

Some additional info related to the responses:
- I used the tune-up kit I bought here on YTMAG (Part No: 2N9NTUNEKIT), which included Autolite 437s, so I assume those are good. I will definitely do the recommended spark and fuel checks.
- I should note that I could not get the new points into proper gap adjustment (couldn"t get any gap at all) because the new part that fits around the shaft was not exactly the same shape as the existing one. I decided to clean the old one off and go with it since I could set the gap correctly, but maybe that wasn"t the right idea. Since I had this same issue before I changed the points I was hoping it wasn"t related. Thoughts?
- Dell, as part of the tune-up I also replaced the coil, so is there anything that could be inducing an issue with coil? Is the tar melting normal operations or is it caused by something else?

 

[souNdguy]

incorrect points gap can /could be causing your problems.

check to see if your dizzy shaft has any play. if it does.. you likely need new bushings.

soundguy

 

[Dell (WA)]

Mark.......you write......"I decided to clean the old one off and go with it since I could set the gap correctly, but maybe that wasn"t the right idea. Since I had this same issue before I changed the points I was hoping it wasn"t related".......wanna bet??? BURNED sparkies are BURNED sparkies, and will NOT CLEAN UP. That is WHY you replace the points.

You do know ittza 2-bolt, 15-min job to remove yer frontmount dizzy and change the points on the kitchen table, don't you??? Just un-snapple yer capple and letter danggle. Points gap is 0.015". You cannot install outta time 'cuz the dizzy drive is an "off-set" slot scheme and only fits one-way.

Just gently start yer 2-bolts and then slide the dizzy back against the block an rotate yer rotor till everything alines up, then titten-up, and snapple-up. Simple, eh?

We don't know WHY the squarecan insulative tar decides to MELT, but it does. I suspect its because the points wear and stay closed longer thus generating more HEAT from longer amps. Specs say points 0.015; I adjust points to 0.017" and the larger gap takes longer to close therefore less heat. .......Dell, yer self-appointed sparkie meister

 

[Old2N]

I have a 2N which would idle fine, but would spit and sputter under any type of load. I suspected an ignition problem, but didn’t know where to start. So I pulled out the distributer and replaced the points and condenser. Put is back together and had the same issue. I then put an inductive timing light on it and wouldn’t you know it? The timing light was flashing in time with the spitting and sputtering. This might be a good diagnostic tool when trying to determine whether you have a fuel or spark related issue.

 

[Old2N]

Oh, an ignition coil fixed mine (6 volt can type).