Sat Aug 11, 2007 7:04 pm

Thanks BD, I'll do that tomorrow!

Sat Aug 11, 2007 7:24 pm

888 wrote:I do believe my friend when he told me it ran last fall...


Something just struck me as I read this in one of your recent posts. I looked back through your posts to the beginning of this thread, but didn't find my answer. When you brought the Cub home did you drain out all the old fuel and replace it with fresh? If not, I would do that now and also check and clean everything from the fuel cap down to the carburetor fuel inlet. That includes the fuel strainer, which you've already discussed, and the fuel line. Make sure that there is no debris blocking the fuel tank oulet hole. Can't hurt. :D

Sat Aug 11, 2007 7:40 pm

Don, thanks for the suggestion. The tank was bone dry when I started out. I pulled the fuel line last night when I pulled the tank and checked it. I never have gotten comfortable with getting that bowl off of the underside of the fuel tank without breaking it but the leaks at the carb tell me fuel is getting through.

Sat Aug 11, 2007 7:45 pm

Sounds good. :D

Sat Aug 11, 2007 8:13 pm

Joe:

Please, no apologies as you did nothing wrong.. at all. As I said in the previous post...

888, I am finally going to take the bull by the horns here, and I am using your previous post as an example.. ok.. strictly an example. IT is not meant in any other manner EXCEPT as a tool to pass on a bit of information.


I also did say in the wagon that it may seem a bit overwhelming, but it is like a good meal.. It is not meant to be eaten quickly, but slowly, savouring each morsel. Small bites and all of a sudden it will be clear.

Oh, here is another gem... check out The Best of H.L. Chauvin.. good diagnostic regimens... filled with home style humour.. just what Dr. Henry ordered :idea: :wink: :D

It was a perfect opportunity to bring up the thought which has been noodling in the back of my brain. Please.. again, do not take it personally.. as it was never meant, and specifically pointed out that it was just an example.

So I would hate to have anything I post be taken the wrong way on this board since you all have been exceptionally helpful and kind to me.


Not a thing wrong... ok.. again, I just wanted to utilize the thread for an example. I need to know how to make it more useful to you all.

I thought buying the manual would have set me up pretty well with what I need but as usual, the manual is no substitute for the experiences you guys have with these machines.


Joe, buying the manual was a smart move... really... But you are right. Some of the guys on this forum have forgotten more about Cubs than the manuals will ever teach. This is true in all things. I have learned so much from so many of them, that I try to repay it by trying to make sure new members have access to stuff some of us older guys didn't way back when.

Also, frustration with one of these simple beasties is a common thread. We tend to make things more complicated than we need to.. I am speaking from experience. But also, experience tells me that all this too will pass. All of a sudden as you methodically go through the diagnostics steps, that poof.. you will find the culprit and it will be something small. It always is.. ANd when you hear it roar to life, you will be knocked flat on your tush, with joy and pleasure from hearing that sweet sound, and knowing that YOU solved it. :!:

Do what you can. You are one lucky guy. I had to wait till my kids were almost growed before I could get me a Cub. You are ahead of the races.. please, do contine.. have fun, don't let it frustrate you too badly, try to find the pleasure in it all and then everything will certainly fall together nicely. It does.. it did for me :!:

Sun Aug 12, 2007 10:06 am

The kids have scouts monday, soccer tuesday and thursday but I can have my wife step in for the soccer thing. Any day you are free and want to make the trip to come down and have a look, that would be great.

Let me check into my schedule for this next week, and I'll get back to you on Monday? I have some mowing I need to try and catch up on, and some office work that I need to wrap up today as well. Without seeing my work calendar until tomorrow, I'm leaning towards Thursday? Be sure to keep us abreast on you troubleshooting and such. You might have it figured out by this evening? I can bring down a carb, and some other items to help troubleshoot the electrical system, if that is where the problem is.

I'll get back to you tomorrow on how my schedule looks

Sun Aug 12, 2007 3:24 pm

Well, I don't have a jumper that reaches from the battery to the coil so I tried something else.

My VOM will reach between the coil and the neg post of the battery. I compared the voltage into the coil from the main wiring harness on the + post of the coil and the voltage from the - side of the coil into the distributor. I'm thinking the purpose of the coil is to build up the native 12 V voltage into high voltage for the spark plugs so I should see an increase in voltage on the output side of the coil. Sound ok?

I compared these two values while cranking. With the VOM set on 20 VDC I had a value of .041 dropping to .038 on both sides of the coil. There was no change in the values on either post oif the coil. Sounds like a dead coil?

BTW, the carb no longer leaks gas since I fixed the float needle last night and the float bowl under the tank seems to have stopped too. I think the side opposite the carb line was a little loose. The plugs smells a little more like gas too.

Is there a shield between the plug and the piston? I have been pulling the plug to check for gas and noticed there was never any difference in the position of the piston in the cylinder. I turned it by hand and nothing inside moved. Just wondering.

thanks as always

Joe

Sun Aug 12, 2007 3:49 pm

888 wrote:
I'm thinking the purpose of the coil is to build up the native 12 V voltage into high voltage for the spark plugs so I should see an increase in voltage on the output side of the coil. Sound ok?

Is there a shield between the plug and the piston? I have been pulling the plug to check for gas and noticed there was never any difference in the position of the piston in the cylinder. I turned it by hand and nothing inside moved. Just wondering.


1. The small terminals on each side of the coil should read battery voltage or less - depends on how the coil is wired. If you have a voltage drop installed before the coil the voltage should be 6 or 7 volts - approx. If the coil has an internal resistor the voltage should read battery voltage on the input side and approximately 1/2 that on the wire terminal leading to the distributor. You can test the voltage by touching the one VOM lead to the coil post and the other VOM lead to the engine block-ground.

2. There is not shield. Perhaps you are looking at the portion of the block containing the valves. Easy test to see if you have compression. Remove spark plug. Finger in spark plug hole - crank over engine.

Eugene

Sun Aug 12, 2007 3:52 pm

Joe - the + side of the coil primar should read 12 volts to ground (battery negative). The negative side of the coil should show 0 volts when the points are closed and 12 volts when the points are open. the coil goes to ground from the negative terminal through the points. If you read the negative terminal while cranking it will just show up as a fluctuating voltage.
Using your meter as an ohmmeter - with the switch off, take a reading from the negative terminal to ground. It should read a dead short if the points are closed which they normally are. You can remove the distributor cap and watch the points open and close. Each time they close, the ohmmeter should read a dead short.
Now, connect the meter as a voltmeter again. Can you confirm that there is 12 volts at the positive terminal with the switch on? Then connect the voltmeter to the negative terminal and verify that there is a zero volt reading with the points closed and 12 volt reading with the points open.
Do this and let me know your results.
I suspect that either the points are not conducting or perhaps the condensor is bad and effectively shorting across the points.

Sun Aug 12, 2007 7:26 pm

Thanks for the information guys. I had some other non Cub things to catch up on to keep peace at the homestead, I'll check more as soon as I can based on your suggestions and let you know what I find.

Joe

Sun Aug 12, 2007 7:56 pm

The spark plug isn't over the piston but over the block surface between the piston and the valves. Nothing should register movement if you're putting something straight into the spark plug hole unless it's catty wampus enough to catch a valve or the top stroke of the piston.

It takes a bit of effort to flood an engine with an updraft carburetor. Gravity and slow air flow thru the intake are on your side. As you've discovered, lots of liquid gasoline drains out through the carburetor intake instead of flooding the combustion chambers. Most of the gas vapor passes out thru the exhaust without condensing on the spark plugs, at least during the dog days of summer.

Mon Aug 13, 2007 7:24 am

Joe, sending you a PM. Looks like Thursday will work into my schedule if that works for you. Then again, sounds like you might have found another area to check which might fix the problem?

Mon Aug 13, 2007 7:46 am

Lurker Carl wrote:The spark plug isn't over the piston but over the block surface between the piston and the valves. Nothing should register movement if you're putting something straight into the spark plug hole unless it's catty wampus enough to catch a valve or the top stroke of the piston.


That makes sense and explains what I am seeing. I'm not used to a head design like this with the plug pointing straight up, but I have seen something similiar on diesels with a preignition chamber. You can't see the piston on those either, I assumed this was similar and it sounds like that passage I see acts a little like a prechamber? Ignition happens in there first and spreads into the combustion chamber?

Lurker Carl wrote: It takes a bit of effort to flood an engine with an updraft carburetor. Gravity and slow air flow thru the intake are on your side. As you've discovered, lots of liquid gasoline drains out through the carburetor intake instead of flooding the combustion chambers. Most of the gas vapor passes out thru the exhaust without condensing on the spark plugs, at least during the dog days of summer.


Yes, as I sat and looked at it, that makes sense. I was actually surprised that the plugs smelled a little more like gas but it told me I was at least getting some mixture up to the plugs compared with before I did the carb work. Again, it's a totally different engine design than what I'm used to, and it's been about 10 years since I worked on gas rather than diesel, and the gas engines were Bosch CIS, not carbed. I just need to think like this engine and not make any assumptions.

thanks for the advice. :)

Mon Aug 13, 2007 8:10 am

Into Tractors wrote:Joe, sending you a PM. Looks like Thursday will work into my schedule if that works for you. Then again, sounds like you might have found another area to check which might fix the problem?


I'll send you a PM in reply. I'm thinking it's still in the electrical system, I need to check the coil and ignition function as BD suggested.

I'll update as my schedule permits. I'm starting to get the "that d*** tractor" comments again from the better half. Of course, having a project car under a tarp in the driveway and an engine and transmissions in the garage isn't helping either. The kids' Radio Flyer has been an engine stand almost since they got it :lol:

The car, engine and transmissions will be gone this weekend and maybe that will help. :idea:

Tue Aug 14, 2007 7:24 pm

Installed new cap, rotor, points, condenser, new battery, and coil tonight individually and not in that order. With only X amount of daylight to work with, I put the parts on and didn't do any testing in between besides turning the key after every part.

Went a few steps backwards for unknown reasons. Battery barely had enough a** to initially turn it over (this is a new development) and once it started cranking it sounded pretty much the same. No attempt to sputter or think about starting.

After spending a lot of time on hands and knees searching for the condensor clip screw in the dirt a few times and trying to balance a MagLite on my knees to see inside the distributor when it got near dusk, I've run completely out of light and patience for the evening. I think the best thing is to walk away and not look at it for a while.

Comments and suggestions are welcome, this is all nut and bolt work, I can't imagine what I could have done wrong, I'll talk to you guys later.