Model 19 Mag ? ( Update )

[FastPaul 0]

I took the engine apart tonight to find out why someone added a 12 volt coil, Figuring the stock coil was junk. I hooked it back up to stock and it has spark?? My B-1 And Larbob"s 725 seem to have the same problem ;They run good cold but after they warm up you can only run at an idle ?? is this a comon problem with the Model 19 mag and coil set up ?? The B-1 after being warmed up will back fire like mad out the exhaust . It seems to be a timming issue"It apears the the timming is ajustable on this set up. Any help to this problem ?? Started painting some of the 725 today .So I thought I'd run the motor on some saw horses today to see if it has the same simptoms as the B-1 and Larbobs 725 ,It ran perfect for a 1/2 an hour on the stock coil ?? makes me wonder why someone would have put a 12 volt coil on ?? anyway She ran good and the paintind is underway!!

[ehertzfeld 1]

Both my 725's and B1 have the same coil, and I have had no trouble with them hot or cold. Oh BTW Paul, I talked to my boss and he will keep it in mined. Hopeful somthing will come up close to you in the next few weeks. I will grab those rims from Rob and keep them in my service truck. I'll let you know as soon as I do.

[FastPaul 0]

Thanks Elon . It just seams srange that somebody wnt through the trouble of adding a coil when the old system worked ??

[ehertzfeld 1]

Well is the timing marks lined up right? there should be a line for the model 14, one for 19, and one for 23.

[ehertzfeld 1]

This is from my B1 that is apart in the basement. God I got the get going on this!:D

[FastPaul 0]

quote:

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Originally posted by ehertzfeld
Well is the timing marks lined up right? there should be a line for the model 14, one for 19, and one for 23.

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It seems to be lined up with the edge of the housing but not the arrow ??

[ehertzfeld 1]

Well you need to check the piston too. I believe when the marks are in line, it the piston should be at top dead center. I'll check my book to be sure, but that is what I remember.

[ehertzfeld 1]

NOPE! I'm wrong!!!!!!! the makes are lined up when the breaker points just start to open. that is right out of the book.

[gregc 3]

Look under "Adjust Rotor Timing": http://www.tpub.com/content/recoveryvehicles/TM-5-4240-501-14P/css/TM-5-4240-501-14P_91.htm

[pullcrazy 0]

paul, my model 700 was doing the same-only run at idle when hot and i'm dying to hear the solution i never figured it out. i suppose i was just afraid to ask. thanks in advance for the solution. jeff

[jgehman 0]

The B1 I just redone didn't run good when it got hot.It lost power till it dyed.Put a new factory coil on an runs good again.:D

[PatRarick 1]

Paul, I had the same problem with a model 23. I switched to battery ignition and automotive coil and it runs fine, but I just HAD to find out where the problem was as far as the magneto. I started switching parts between a good running model 23, one piece at a time to try and pinpoint the problem. Never did find out what was wrong. This one particular engine, when warm, simply will not run above idle with the magneto. The donor engine ran just fine with the parts from the problem engine, and it runs fine after it's original parts were returned. I switched EVERY part, right down to the wires and point box. Starting to wonder if one or both of the main bearings could be worn enough to cause the rotor to shift position at higher rpm's, affecting the electrical generation of the mag.

[MPH 12]

Paul, yours looks to be way off wack. Maybe the last guy in there had no clue what he did wrong so he added the external coil. My 725 and LL with model 23D have never given any trouble once I adjusted the points and I think in the LL I replaced the points and condenser when I was getting it going. I'd say try checking to see if it fires the plug close to top dead center, if not, move to the arrow and try that. Will be interesting to see what you find.

[Roy 0]

My B-1 would run fine until it got hot and I went up hill or popped a wheelie, then it started missing and sputtering at anything above an idle. Drove me nuts for years. Tried a used coil once, no help. Finally put an electronic ignition module on it and solved the problem. Except, it had a tendency to kick backwards when starting. Think maybe the timing needed to be retarded with the ignition module. In my case, I've convinced the problem was/is excess camshaft axial play as diagnosed by Al Eden. Per Al, with excess cam end play, and/or a worn points lobe on the cam, the point gap would change and cause missing. I think Al was correct in this. Bottom line, make sure the cam axial end play is within factory specification and inspect the points cam lobe for wear. My experience,

[Lee 0]

Hi new to the club 8D I have 63 sears suurban 725 with a model 19 that runs fine when cool but when it warms up it starts cutting out and sometimes dies. at first i thought carb but no adj would work so i asked around and according to the people ive talked to the model 19s coil being as its behind the flywheel and not above the flywheel it does not cool and it overheats and finally i belive burns out[XX(. Aleast thats what i was told but it makes sense to me thanks Lee

[PatRarick 1]

Roy, and/or Al, I could go along with the worn camshaft causing such a problem, IF it would run just as bad with battery ignition. With battery ignition, it's still running off the points just as it is with the magneto. Wouldn't a worn cam cause the same problem with a battery ignition as it does with the magneto?

[ka9bxg 3]

Paul I know from working on a lot of model 19 engines. You have a bad coil.No problems with the timing carb or cam It is the coil. I am sure after you replace the coil on it it will run fine.I was buying coils 2 at a time for my wonderboy 700s and B1s I have 6 model 19 engine and all of them needed coils.Don't forget that those engines are at least 40 years old. Good luck. Bob

[ehertzfeld 1]

Bob, it was running poorly using a 12 volt coil, not the original one. Hes is just trying to figure out why some one changed, when the old coil has spark.

[johnmonkey 4]

I'm not sure if this could be a problem, but does the model 19 have a points plunger like a model 19d? my 19d is very difficult to adjust the points, because the points plunger has shortened over time. It is on the list of things to do. JH

[Roy 0]

Pat, "Wouldn't a worn cam cause the same problem with a battery ignition as it does with the magneto?" Yes, a cam problem should cause missing with either points or a magneto. In my case the electronic ignition module solved the problem by eliminating the points and with the same coil. JH, My Model 19 has a lever arm, instead of a plunger, that rides on the cam lobe to activate the points. Lee/ka9bxg, Frequent coil failure due to over-temperature makes sense but in my case it is a cam problem. Otherwise, the ignition module would not have fixed the problem.

[FastPaul 0]

It runs great with the 12 volt coil , the problem I have is with the B-1 and Larbob's 725 after reading everyones coment it seens to be a common problem, I just whan to make it stock and have it run like it should , I'm going to bench run this engine on the original coil and see if it runs good, There must be an answer to this problem, Thanks for everyones input

[ka9bxg 3]

You will have spark when turning it over but when it gets hot it will miss fire If you put a spark tester on it it still looks like good spark.You can not see the missing spark at that high of rpm.There might be other problems like the plunger but the cams never seem to wear out. Good luck Bob

[PatRarick 1]

quote:

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Originally posted by ka9bxg
You will have spark when turning it over but when it gets hot it will miss fire If you put a spark tester on it it still looks like good spark.You can not see the missing spark at that high of rpm.There might be other problems like the plunger but the cams never seem to wear out. Good luck Bob

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Have to disagree with you on that point Bob. Using the briggs spark tester, it was very easy to see the missing spark at the higher rpms on my model 23.

[RayS 80]

quote:

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Originally posted by Roy
Pat, "Wouldn't a worn cam cause the same problem with a battery ignition as it does with the magneto?" Yes, a cam problem should cause missing with either points or a magneto. In my case the electronic ignition module solved the problem by eliminating the points and with the same coil. JH, My Model 19 has a lever arm, instead of a plunger, that rides on the cam lobe to activate the points. Lee/ka9bxg, Frequent coil failure due to over-temperature makes sense but in my case it is a cam problem. Otherwise, the ignition module would not have fixed the problem.

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I have to agree with Roy on the electronic ignition. Eliminate the points and go with electronic ignition. when the points plungers wear and the cam you are just going to have problems unless you replace them. I have a 12hp Briggs that I replaced the points on 4 or 5 years ago now with the electronic ignition and haven`t a problem since.