Mccormick Deering LA engine

[Dieselcowboy 210]

I have just traded for my first engine. An LA. I am having trouble with it not starting very easy. Like I have blisters after I am done. It wants to go but backfires and starts to roll backwards. I thought maybe the timing might be off so I re timed it. No luck. I don't hear an impulse click like my "A" JD makes. Never the less if I get gas to it , the fire is there. Anyone ever had a similar problem?  After it finally starts it really pops hard when it runs. Is this normal? I thought it should be a little smoother.  Like I said this is my first one and I am clueless here.

[roscoemi 245]

I have never seen that engine, but the Tecky in P'Chops tractor did the same thing with a bad set of points that would not fire on time. Changed them out with another set at the right gap and it's fine now.

[rydogg 186]

Check out smokstak.com I am including a link about some LA starting issues but you can also search the site for more information.

 

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDMQFjAA&url=http%3A%2F%2Fwww.smokstak.com%2Fforum%2Fshowthread.php%3Ft%3D78514&ei=Y_91UeedCOLi2gXo4IDoBw&usg=AFQjCNE1Lqjztra37LSeYJEaeK32m-_VEA&bvm=bv.45512109,d.b2I&cad=rja

[1054josh 25]

Sounds like a weak mag you might need to get it recharged also.

[Dieselcowboy 210]

I dont have the original gas tank on right now either. I have heard the gas line is suppost to have a check valve in it. Maybe the hose for a gas line could be hurting my efforts too? It is about 6-8 in longer than the original metal fuel line to boot.

[1054josh 25]

Yes definitely needs the check valve. My sattley wouldn't start till I put that little guy in the line.

[Heine92 0]

You need a check valve so the fuel will stay up by the carburetor to since the tank is lower than the carburetor. It is the same concept as the early briggs and stratton engines that had no float and the used the suction of the intake to pull the gas up the line and the check valve is needed to keep the fuel right up in the top of the line because with out the check valve the gas will run right back down in the tank and the engine has to keep sucking the gas up the line again until the gas is high enough to get in the carburetor. ones the engine is running though, if it is running fast enough the gas will stay up at the carburetor since the suction of the intake is so frequent. That would be a lot of the reason as to why you are having so much trouble starting the engine. if you want to see if that is the root of your problem, you can try and make a gas tank from a briggs or any other kind of gas tank that has a check valve on it plum into your carburetor and try it. You could also slightly push down your choke plate on the carburetor and cheat by dumping gas or spraying starting fluid in directly into the carburetor, this would let you know because with a good clean check valve you should get gas in the carburetor in a couple cranks of the engine. 

 

Also you should be able to here the impulse on the magneto just like you can on your John Deere A, if not that can also make starting the engine a lot harder. If you spin the engine to fast the impulse wont engage, but if just rolling the engine over slowly and there is no impulse then something is not working right to engage the action of the impulse. If you are saying you can start the engine without having the impulse on the magneto work then you have a pretty hot magneto and would more than likely not need to be charged. And also what do you have for a muffler on the engine if there is no muffler of any type on the LA/LB engines except for maybe a pipe they can be super loud. Even with the muffler on they can still be loud.

 

The engine sounding loud could also mean that the spark is retarded to much on the engine. There are marks on the flywheel to show where the magneto needs to spark, this is hard to explain since i haven't messed with timing one up in a long time, but there should be if you look in the outside of the flywheel a dash on there. This mark should be lined up with a mark that is made in the top of the backing plate behind the flywheel. If yours has the throttle rod then the mark on the backing plate would be in the are where the rod is set to make the engine run full throttle. 

 

I hope this helps you out some.

[Dieselcowboy 210]

That is a great help. I may get a new fuel line and check valve. The mag has what looks to be brand new points in it. I suspect that it has had some work done to it. I rolled the engine over slowly and it does not impulse. Wonder if that may be an easy fix? may have to take it to a repair man. There is no adjustment on the mag except the timing itself correct?

Do you know the proper way to time this engine? I am a little scared of being bit by the mag when I roll the mag over off the engine in my hand.  Can you tell I have been hit before?

[KC9KAS 4,741]

Heine92  I see you have been a member for a little over a year, but this was your 1st post, so,  .

It sounds like you know a lot about "hit & miss" engines.

My B-I-L has several.

[Heine92 0]

Thanks my dad and i work on hit miss engines a lot as we have quite a few of them and have recently gotten into garden tractors a few years ago. To add about the impulse not working on the magneto, sometimes when engines are not ran for a long time the impulse spring and teeth the do the impulse for the magneto will became stiff and need cleaned or lubricated since when the engine is ran the oil in the crankcase is brought up on the gears and can lubricate these. What my dad and i do sometimes is take the mag out and and spray penetrating oil behind the mag gear and keep messing with the mag spinning it over, we actually did that on a mag for a two cylinder wisconsin the other day. If that still doesn't help the situation out, if you go to the Portland, IN engine show or swap meet, Mark's magneto will check it for you and can tell you exactly what is wrong with the magneto, unless you have faith that you can fix the impulse which is right behind the mag gear. I have never had much luck working on them but but as i stated before that was when i was a lot wronger and wasn't as familar with antique engines. 

 

As for the timing of the engine, according to the manual that i have (which could be purchased at most antique engine shows) you will line the mark on the flywheel labeled as D.C. with the backing plate on the engine. After that is lined up you will take your magneto and there is a mark on the gear, which should be a dot of some type punched into the gear, with the the mark on the actual magneto casing, this too should also be a dot punched into the casing flange. You then will put the magneto in and snug the mag bolts and roll the engine to make sure that when the engine comes up on compression that the impulse on the magneto will snap when the D.C. mark on the flywheel and the and the engine line up. If not, then you can turn the mag slightly one way or the other to adjust the timing.

[Dieselcowboy 210]

I will definitely be putting all these ideas to use. Everyone is really helpful in the most unlikely place, a wheel horse forum.

Is there any way the mag can bite me if I hold it in my hand and roll it over, to find the impulse?

[diesel cowboy 263]

Only if you've got the plug wire on it and you touch it or if you manage to some how get your finger into where the plug wire goes in the cap.  Other than that just be carefull when turning it over by hand if the impulse grabs and you go past it to make it release then the gear jumps ahead real fast.  I've tore off more than one finger nail doing that cause I wasnt paying attention.   Stewart