help convincing my big brother

[losthismind]

my brother has a mutt tractor 6v. front dist. 9n motor.problem is starts hard, low power rebuilt carb, new fuel line and shut off plugs wire points gap at .015 cap still hard to start. so i thought lets do a compression test only check #4&3 cyl. both had 70# found the problem. tell him we need to rebuilt and he checks with a differnt guy who tells him to convert to 12v. and his problem will be solved.what do you guys think.by the way he sure likes my naa in the mean time. sorry so long

 

[Ed S.]

Converting to 12v is only treating a symptom, and while it may provide some improvement (plus the ability to run your 8-track player), it sounds like he's got other problems which are only gonna get worse, overshadowing any benefit 6 extra volts will provide.

My freshly redone '50 frontmount starts and runs real easy on its OEM-designed 6v system. The tired-out '50 frontmount I borrowed while rebuilding mine also started and ran fine on 6v after replacing the wiring harness (under $30 - CHEAP) and tuning up the points, etc.

His tractor, of course, but I'd advise as much overhauling as his budget will allow, starting with a thorough check of the ignition circuit (all connections clean, bright and tight, etc.). Do a dry and wet compression test to get an idea of whether you're looking at worn rings or valves... might be able to get away with a ring job for now. What's the cold and hot oil pressure look like?

es

 

[Leemo]

He may get it to start easier with 12V but it'll still be low on power and in time it'll be just as hard to start on 12V and have almost no power. Like a '52 8N I had. It'll probably start running hot before long too because it's going to be trying to work a too tired engine. If he plans to keep it he'd be smart to do the overhaul and save his $100 or $150 from a conversion to spend on overhaul parts. Just my opinion.

 

[old]

Yes 12 volts would make it start easier but it would still be a weak tractor at best with compression like that. A good engine will have 90pis min. and a real good engine 120psi plus so he just plain has a tired engine that needs a lot of TLC and while 12 volts will help it start will not in the long run save him any $$

 

[Bob]

Warm it up, remove all the spark plugs, open the throttle fully, then run a REAL, complete compression test on ALL 4 cylinders and see what you have.

 

[Paul in MN]

To reduce any other errors, make sure the choke is fully open (knob pushed in) and take the air cleaner tube loose from the carb intake. Sometimes the air cleaner is filled with crap that chokes off the engine air.

Tell us all 4 cylinder readings without oil, and then with a teaspoon of oil added to each cylinder. You may need to keep a battery charger on the batt while testing to get about the same RPM for each cylinder test.

Paul in MN

 

[Bruce (VA)]

If it indeed has bad compression, then by all means, convert it to 12v. That way, you will have an easier to start poorly performing engine instead of a hard to start poorly performing engine. That's called reinforcing failure.

Like the others have said, do the compression test correctly & post back. If it has fair to average compression, there are a number of things that you can do to help it to start easier.
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