HS40 Rupp

#62
Have the engine buttoned up, new points and condenser, tried timing it last night, dial indicator and ohm meter. .035 BTDC, its like i don't have enough movement for adjustment. Best i could get was .080 BTDC. What am i doing wrong. I'll try it again tonight. @delray bummer, plans changed can't make it to SYMCO, I am bummed :(
 

markus

Well-Known Member
#63
Have the engine buttoned up, new points and condenser, tried timing it last night, dial indicator and ohm meter. .035 BTDC, its like i don't have enough movement for adjustment. Best i could get was .080 BTDC. What am i doing wrong. I'll try it again tonight. @delray bummer, plans changed can't make it to SYMCO, I am bummed :(
???? .035 will show up on the dial well before .080 will, Before tdc.....so go to tdc set guage to zero and spin the crankshaft counter clockwise facing the flywheel/point side of engine

View attachment 246841
 
#64
I probably didn't explain it very well. I pretty much followed the process you mentioned markus, but could not get continuity @ .035, so I just positioned/rotated the ignition coil to the end of the slot and tightened to the two bolts. Then I rotated the crank very slowly, and when I got continuity my dial indicator was @ .080.
I hope this makes sense.
 

markus

Well-Known Member
#65
Dalpan, I had an H35 on the bench that I was at the point of setting the timing on so I did a video and tried to think of all the stupid little things that have screwed me up in the past when setting one up and tried to throw that info in while I was doing it. Not real sure offhand why you cant get a reading near where you need to be. Sorry I have just an old camera and I ramble and mumble :) It will maybe tide you over till one of the experts chime in at least

 
#66
FWIW
I put the crank so the mark on the points cam lines up and set the points @ .020”.
Then set up dial indicator and set crank so that the piston is the proper distance BTDC. This value is different depending on the engine. On my Hs50s I set it at .035” BTDC which is what I think the manual calls for.

Then the stator plate is loosened, and moved until the points just break as checked with the meter, and then tighten down the stator plate. The crank is not turned during this step. I have never had any problems doing it this way.
I thought I had read about people filing the mounting slots to rotate the stator plate a little more, but I have never had to do it.
 

markus

Well-Known Member
#68
FWIW
I put the crank so the mark on the points cam lines up and set the points @ .020”.
Then set up dial indicator and set crank so that the piston is the proper distance BTDC. This value is different depending on the engine. On my Hs50s I set it at .035” BTDC which is what I think the manual calls for.
.
The little cheater marks most likely wont be found on old HS40's like the OP is working on, so I felt it was not worth mentioning. Tecumseh updated the cam breaker lobe (part number was the same) into the 70's and the arrows and even the slots that the wear block should sit at on some of them when timed properly were added later on in production. They also changed the ramp design so the points didn't close as fast.

I have ignition parts out on the bench right now so I took some shots of the breaker lobes for reference:

IMG_1267.JPG

As you can see there were all types of little marking they used as the years past, Note that the H25-35 have the triangle and cross on them but if someone said to set your points using that as a reference....Houston, we have a problem!!! on the early HS ones and most of the small Frame H breaker lobes the center of the arrow would be the high side if you really need a reference point to find the HIGH side.

IMG_1268.JPG

note the variations, Cross, triangle, even a P for (points). The 2 lines I have found will line up with the wear block when everything is right and new or near zero wear parts/assembly, But I would not put total trust in that and apparently Tecumseh does not either since its not noted in any manuals I have seen. I suspect it sped up assembly line setup.

IMG_1269.JPG
 
#69
Dalpan, I had an H35 on the bench that I was at the point of setting the timing on so I did a video and tried to think of all the stupid little things that have screwed me up in the past when setting one up and tried to throw that info in while I was doing it. Not real sure offhand why you cant get a reading near where you need to be. Sorry I have just an old camera and I ramble and mumble :) It will maybe tide you over till one of the experts chime in at least

markus appreciate you taking time for the video, you are a teacher of the hobby...I removed the stator plate and started over, Checked everything you mentioned and others. Made sure the slots were clean. Reassembled and think I got it. Sometimes you gotta step back and slap yourself, be patient and not get frustrated. My homemade dial indicator base & meter got the setting to just flicker at .035.
Again I appreciate the assistance. I'm sure some of you long time hobbyist just roll your eyes with some of these road blocks us rookies come up with.
The information you are sharing has been very informative.
Stay tuned, more roadblocks may be ahead. :) hs40 timing.jpg
 
#70
Awesome, glad you were able to get it! Don’t worry about making mistakes, we all do and that’s part of the learning process.

Markus thanks for those pics, had no idea the points cams changed that much! I have seen the triangle marks, and the + marks but never knew there were that many variations. Without any markings I can see how it is confusing and more difficult.
 
#74
I'm pretty green at this but if you mean a bearing for the crank journal you shouldn't need one. I installed the billet rod, which measures 1.0023 to the crank. That is what i learned from others much more knowledge than me.
I'm pretty green also, that was the question, and a great answer. Just smack that bad boy in there!?!
 
#75
Slow but sure, everything is buttoned up. But have a concern. The key for the flywheel measures .124 and the key slot on the flywheel measures .130. To much slop? When I slide the crank on and seat on the taper, I can move the flywheel on the crank, it's like the key is rocking. Will this throw the timing off? I had it together once and tried to start the engine :confused: no luck. So i removed the flywheel to inspect. Any feedback would appreciated.
 
#76
Have you lapped the flywheel to the crank?
New keys are cheap, if you think it’s damaged I would replace it, it won’t start and run well if the flywheel moves.
 
#78
I just measured a new key and got .125”
Pretty hard to get a good read on the flywheel I have sitting here, it is a Hs50 full sized aluminum flywheel so the fins are deep making it hard to get a good measurement as the caliper should be 90 degrees in both directions.

The only way I could get .130” out of it was to hold it at an angle
 
#79
Sorry I forgot to include that the flywheel measured .125-.126”

Also I assume you are using the same key as this, as this is an Hs50 engine but I am running two Hs50s with Hs40 flywheels so I am pretty sure they are the same.



 
#80
Sorry I forgot to include that the flywheel measured .125-.126”

Also I assume you are using the same key as this, as this is an Hs50 engine but I am running two Hs50s with Hs40 flywheels so I am pretty sure they are the same.



You can get the flywheel a bit more accurate with a sloppy key of known dimensions and slip a feeler gauge in beside it. Clean surfaces and some patience for me has worked.
 
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