looking for small engine guys

[skinny]

I have what i think is a 8 hp tecumseh on a john deer blower the timing is off and I need to know how to reset it if someone could direct me in this it would be great.

Edited December 24, 2010 by skinny

[Big Cliff]

I have what i think is a 8 hp tecumseh on a john deer blower the timing is off and I need to know how to reset it if someone could direct me in this it would be great.

 

Unless it is a VERY old machine (points and condenser) you can't adjust the timing. What is it doing that makes you think the timing is off?

[Fisherman]

Well there is this possibility that I've seen on a couple machines. Under the flywheel there is a woodruff key that "locks" the flywheel to the crankshaft, (usually a small square rod about 3/16" square, although some have a slightly different shape). On my brothers old Toro, it sheared and allowed the flywheel to rotate about 1 inch, you should have seen the flames coming out of the muffler, similar on another machine, no flames but it had about as much power as a hand held egg beater. Replaced the woodruff key, all was well. If you take off the engine cowl with the pull start, you should (not all) be able to see the machined slot cut into the side of the top of the crankshaft and the matching cut in the flywheel. Some have the slot a little lower down on the crank unfortunately hidden by the flywheel. Let us know, many can learn from this.

[skinny]

this is an old points unit

the fly wheel is off

the unit was backing up thru the carb and hard to pull so I started looikng into things and found that the bolts holding the timing palte were kinda loose and have allowed the plate to shift making it out of time

this is on a deer 726

[Big Cliff]

Well there is this possibility that I've seen on a couple machines. Under the flywheel there is a woodruff key that "locks" the flywheel to the crankshaft, (usually a small square rod about 3/16" square, although some have a slightly different shape). On my brothers old Toro, it sheared and allowed the flywheel to rotate about 1 inch, you should have seen the flames coming out of the muffler, similar on another machine, no flames but it had about as much power as a hand held egg beater. Replaced the woodruff key, all was well. If you take off the engine cowl with the pull start, you should (not all) be able to see the machined slot cut into the side of the top of the crankshaft and the matching cut in the flywheel. Some have the slot a little lower down on the crank unfortunately hidden by the flywheel. Let us know, many can learn from this.

 

You have probably hit the nail right on the head but before I got him to try and pull that flywheel off I thought I'd better get more information. Sometimes those flywheels can be a bugger if you don't know what you are doing. Mess up the threads on the crank shaft and you can have a real problem LOL.

[Big Cliff]

Turn engine over until rubbing block is on the high side of the cam.

Set Points to .020 thou. That should do it for you.

[skinny]

this is more that set the points as the whole block that the points are housed in is loose on the motor so I need to know how to set that part up again

[Fisherman]

Another stab..the lower part that holds the points and condenser should have fixed mounts, then the point assembly is added above that with adjustable screws, like B/C said, for the final set up.

[Big Cliff]

this is more that set the points as the whole block that the points are housed in is loose on the motor so I need to know how to set that part up again

 

I am just leaving to go out for the evening, but send me a picture. [email protected] I'll get back to you tomorrow.

[irishfield]

I fought back firing thru the carb on my john deer riding mower.. figured it had to be bad timing.. firing before TDC.. I pulled the wheel.. jammed the pick up as far as I could in the direction of rotation etc. Didnt' change a damn thing... turned out all it was was a bad spark plug. Changed that and it's worked like a top ever since. Sometimes the solution is just too simple to realize that your have real greasy hands and wonder why!

[skinny]

here is some pictures of the plate I need to find out how to set up as it was loose on the engine.I know this has everything to do with timing

[discophish]

Perhaps the parts fiche will help you out.

 

When I'm looking at something upside down, I go to the fiche to make it right side up for all of my stuff.

 

Since you are looking at JD blowers, go here:

 

http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

 

Type in your model. It should give you an idea of what you are looking at.

[Big Cliff]

I have to be honest, I am going to have to dig through my manuals because I can't see what it is that you are trying to explain. I must be missing something. Any of the ones I have ever worked on have a pivot screw and a locking screw. You adjust the plate so that your points are set then tighten the locking screw and pivot screw. It is so much easier when you have it in front of you lol. let me do some digging and I'll see what I can find.

[Big Cliff]

OK, PM me your email address and I'll send you PDFs of the pages you need with step by step instructions. If that doesn't do it for you, you'll just have to make a road trip over here.

[Big Cliff]

OK, step by step:

1) Turn the engine over until rubbing block on points is on high side of cam.

 

2) Set points at .020 with piston at TDC (should be about 4° BTDC but you really need a dial indicator to do that).

 

3)Rotate the stator until the points just break (you can use an OHM meter or continuity light if you have them) Tighten the stator bolts!

 

If you are confident that the points were set properly before, just go to step 3

[skinny]

I have a dial indicator can you tell me the measure ment the 4degrees turns into

[Big Cliff]

OK, the modle number of that engine should be stamped into the blower housing. If you are right about it being an 8 hp the modle # will be H80, HM80, or HHM80 in which case the timing dimension BTDC will be .090". If it is anything but one of the above modles let me know because it can range from as low as .035" depending on which modle it really is.

 

Trying to explain this is like trying to tell someone how to ride a bike.It is easier to do than it is to explain LOL.

[skinny]

ok here is what I could read off the housing the ?marks are curently not legable but i think by the looks of it we just need first 3 so

H70-1??-159?-ser7201D

and thanks for the help

[Big Cliff]

not that it matters a whole lot but the H70 or 80 actually refers to the cubic inch displacement not the hp.

 

H70

.050"

 

And you are welcome!

[Bernie]

Could be wrong here but I think what he is trying to set is the coil to the flywheel clearance.

It appears in the pictures that the coil bracket was loose by the rust around the bolts and slots.

If the clearance is too large it won't charge the coil, too close and it rubs the flywheel.

In a case like this just keep moving it outwards until it begins to touch the flywheel and then back it off a little bit. 10 thou should do, need a little room for expansion.

Then you can set the points as Cliff has said.

[Big Cliff]

Could be wrong here but I think what he is trying to set is the coil to the flywheel clearance.

It appears in the pictures that the coil bracket was loose by the rust around the bolts and slots.

If the clearance is too large it won't charge the coil, too close and it rubs the flywheel.

In a case like this just keep moving it outwards until it begins to touch the flywheel and then back it off a little bit. 10 thou should do, need a little room for expansion.

Then you can set the points as Cliff has said.

 

Bernie, you could be right here, I'm not 100% sure. I got the feeling that he was talking about the stator bolts being loose. If it is the flywheel gap then .010 would work just fine, the specs call for .015 but to be honest in the shop a tight .012 shim would have been used.

 

It is always hard to give someone advice based on limited knowledge! I love to help people but as you and I both know the sound, feel, smell, and yes, sometimes just plain intuition play an important part in trouble shooting. How do you explain those things to someone else LOL.

[aplumma]

Bernie, you could be right here, I'm not 100% sure. I got the feeling that he was talking about the stator bolts being loose. If it is the flywheel gap then .010 would work just fine, the specs call for .015 but to be honest in the shop a tight .012 shim would have been used.

 

It is always hard to give someone advice based on limited knowledge! I love to help people but as you and I both know the sound, feel, smell, and yes, sometimes just plain intuition play an important part in trouble shooting. How do you explain those things to someone else LOL.

 

 

You are so right how can you tell if it is a stuck needle on the carb if you don't taste the oil???

 

 

Art

[Big Cliff]

LOL, this from a guy that calls me and asks "can you hear that?" "what do you think it is?"

 

Art, you are just too funny my friend!

[aplumma]

LOL, this from a guy that calls me and asks "can you hear that?" "what do you think it is?"

 

Art, you are just too funny my friend!

 

Yes that is true that I had to call all the way up to Canada to get an answer from someone I trust. The irony of it is even with a bad phone connection you still heard the sound of 2 of 6 coils being bad. Now hurry up and move closer please we have over 100 cylinders on the farm and counting...

 

 

Art

[Big Cliff]

Is it warm down there?