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Spencyg

The engine rebuild plot thickens,,,,

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Spencyg
...boy am I tired of this topic! I am very grateful to those who have already offered possible solutions to my problems...unfortunately the engine still does not run. I replaced the spark plug as suggested without any luck. The only time the engine will fire is if the throttle is wide open. With it wide open, the engine will very slowly run, but making just a "Pop pop pop" sound. At lower throttle settings it will not run. I believe I screwed up the camshaft phasing! It appears as though the camshaft timing is off by a couple of teech. I don't know how this happened, but it is going to require removal of the engine to find out. Just my luck. Anybody know an easy way to remove the front bearing from the crankshaft so I can see the crank timing gear? Thanks Spence

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Spencyg
The carb was operating perfectly when removed for the rebuild. I would otherwise agree with you, but I never actually lined up the two "dots" on teh timing gears...rather went by a scribed line in the crankshaft. I was hoping it would be enough, but now I don't think it was. It is acting as though it is only out by a tooth either retarded or advanced....god am I nnoyed with this thing. Spence

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arjr111
The tooth relative to the timing mark on the cam, is supposed to line up with the front/face of the tooth on the crank mark. It can be tricky because the tooth actually curves. It looks like it is lined up but it is actually on the tooth prior to the one it should be on. When you tear it back down, you will need to carefully mark the face of the tooth with crayon or nail polish that is aligned with the crank timing line. And then carefully place the cam gear with it's mark right over the marked tooth. Briggs could have made it much easier by just putting the timing mark on the face of the correct crank tooth, but noooooo!

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PatRarick
On those engines, I clean the crankshaft cog and the two camshaft cogs with carb cleaner to remove all traces of oil. I paint across the crankshaft tooth and continue a about 1/4" onto the gear. I paint both teeth on the cam and also about 1/4" onto the gear. Makes for much easier alignment. Pat

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Spencyg
Thanks for the input gents. I'll be tearing into it this evening for a final time (hopefully). Any suggestions as to how to remove the crank bearing on the PTO end of the engine? Can I use a bearing puller on the race? Spence

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arjr111
quote:
Any suggestions as to how to remove the crank bearing on the PTO end of the engine?
I have read that the best way to do this is to carefully heat up oil in a roasting pan, lay the crank in with the bearing covered and let it heat up. Then it should come off easy with a bearing puller. But, you should not have to do this to get the cam and crank lined up properly. As Pat says if you mark from the timing mark to the tooth "Front" of the tooth that lines, up with it you should be ok. Just do not line up with the back of the tooth that is directly on the line, cause thats the wrong one.

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arjr111
Yeah, Briggs sure managed to make it difficult. And, don't feel bad I did the exact same thing, and had to tear back into the engine. A lot of us have made this same mistake.:(! When you take the cam out, and you look at the crank timing line from the front, looking across to the line, there are only two teeth the cam mark can possibly line up with. The one that is on the line at the back, close to and emanating from the crank timing line, it curves away from the timing line. And the one that is not on the line in the back, but curves towards it in front, where you can actually see what you are doing. The latter is the one you want, so if you color the face of that one, where you can actually see, and then run the line down from the cam mark to the appropriate cam tooth, it should be perfect.

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Spencyg
OMG...now I'm confused. There is a very faint line on the back of the cam gear with a punched mark. There is also a very faint line on the front of the cam gear with no punched mark. You are saying that I follow the tooth that is marked by the front line? I assume follow it as it angles back toward the back face, and then line up that tooth edge with the mark on the crank gear? If so, than I gotcha. I still need to get that damn bearing off. Spence

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arjr111
Sorry for the confusion. It is a little difficult to explain, but I understand what you are saying, the crank bearing really makes it difficult to see any mark you make on the crank teeth, and you really can't see the face of the crank gear. But, that is why you need to carefully determine the correct crank tooth and color it. If done carefully, you can see the colored tooth as you place the cam back in. This step is where many people make the mistake of marking the wrong crank tooth. The tooth that starts out on the crank timing line is not the right one. The tooth that starts to the left of the crank timing line and the ends up in front of the line (close to the crank bearing) is the correct one. The Cam gear face should have a round punch hole. Follow (and mark clearly), that mark down to the correct groove. The tooth you color on the crank should be placed in that groove on the cam. Or, if you mark the two teeth on the cam that are below the cam gear mark, then the colored tooth on the crank should fall between those colored teeth. Hope, this don't add to the confusion. If someone else can explain it better, jump in!!

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Spencyg
After hours of wrenching on the old Simplicity, I have come to a number of conclusions. #1 conclusion is that the cam timing is correct. I pulled the bearing from the front (without even removing the engine) and the marks are lined right up. After reassembling, I attempted to start the engine, but it would only start when I pushed against the govenor to reverse the throttle position. I looked closer, and the govenor was holding the throttle wide open. What is wrong here? When I removed the rod holding the throttle open from the "idler" arm,the engine would start, but ran rough and erratic. It was also very difficult to start and required about 1/2 choke to keep running. I figured the hardness of starting was due to ignition timing,so I removed the engine, and took it back to the magneto.I set it to the center of the adjustment, and started puting the flysheel back on. Whe installing the small key, it appeared to be sheared (aluminum). I made another one out of mild steel, and reinstalled the engine making sure all clearances were OK. After installing it in the tractor, I turned the key and it again started right up without the govenor linkage. It now is shooting some flame out of the open exhaust pipe (no muffler...just 6" of pipe) but running much better. I think my carb is to blame. What other tests can I do to isolate the problem? I am pretty sure it is 100% fuel delivery now. Spence

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BLT
Well first of all put a new original aluminum key back in. If not, you might have problems later, from sudden stops tearing up the keyway or whatever. The carb problem might be some adjustments and to be truthfull I haven't followed your dilema all the way.

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Spencyg
I'll get around to ordering a key soon...for now the steel one will have to work. Does anybody have any blowups of how the mechanical govenor is supposed to be hooked up? As I said, it is disconnected right now because it isn't working correctly. Any thoughts on carburetor adjustment? Spence

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arjr111
Correct torque on the flywheel and the key are important. A partial flywheel key sheer will also give you the hard starting problem. And, having a home-made (slightly loose) key might just imitate a partial sheer. I would put a spec. flywheel key and torque to specs. then see if there are still problems.

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Spencyg
The key I made is tight with no more than 0.002" slop. Do you suppose that the engine timing is now too far advanced because of the occational flames being thrown out of the exhaust pipe? Spence

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PatRarick
The flywheel key is a "locator", not a driver. It is made of a soft material to protect the crankshaft and flywheel. I have seen instances where the use of a steel key has split the flywheel in an instance where the OEM key would shear. I have also seen where the use of a steel key and improper torquing of the flywheel nut have wallowed out the crankshaft and flywheel keyway. As to the flames from the exhaust, this is generally a sign of too lean of a fuel mixture. Pat

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arjr111
quote:
Does anybody have any blowups of how the mechanical govenor is supposed to be hooked up?
[img]http://www.simpletractors.com/club2/attach/magoo/300401%20to%20300424.jpg[/img]

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darylcress
I do not know if I would be too worried about the flames at this point. Most engines, Kohler, Briggs, Ford, etc. will have flames out a straight short exhaust. Get it running correctly first. Carb Adjustment: With a warm engine running at fast (rated) speed, turn high speed needle (one on bottom of bowl) in until engine slows (lean), back out until engine engine runs rough (rich), then back in to a mid point between lean and rich. Holding engine against idle stop, repeat t he process on the idle valve (one by the throttle plate). If engine will now not operate properly, richen mixture slightly. Hope this helps.

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BLT
For the most part most engines when stopped are in the wide open throttle position as throttle arm is always under the slightest governor spring pressure even when stopped. Another thing you might want to do after you get the carb adjusted if that's what it is, is to check the governor arm to throttle plate adjustment. Look at Arts picture. The governor arm is up when the carb is in wide open throttle. To get the correct adjustment, loosen the nut on the governor arm only enough to where you can make the shaft turn with a small screwdriver in the governor shaft slot. Position throttle plate to WOT with governor lever. Then turn governor shaft couterclockwise until it stops. Tighten nut on governor arm. Move the linkage to check for binding. You're then good to go.

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