Need a little guidance on Fox trail tramp w/ HS40 tecumseh
You don't have to remove the camshaft to replace the valves, but if you're going to replace the rings, you'll have to remove the piston, which will require you to remove pretty much everything from the engine.
I forgot that you had mentioned you replaced the points/condenser before. You'll probably be safe to leave those alone for now, but maybe check the points for corrosion and clean them if necessary.
As far as tools go, you might want to pick up a valve spring compressor. You can do it without the tool, but it's really difficult. Another one to look at is a piston ring compressor. Once again, not entirely necessary, but will make your life easier. The rest is pretty basic -- torque wrench so you can tighten stuff to spec, etc.
I forgot that you had mentioned you replaced the points/condenser before. You'll probably be safe to leave those alone for now, but maybe check the points for corrosion and clean them if necessary.
As far as tools go, you might want to pick up a valve spring compressor. You can do it without the tool, but it's really difficult. Another one to look at is a piston ring compressor. Once again, not entirely necessary, but will make your life easier. The rest is pretty basic -- torque wrench so you can tighten stuff to spec, etc.
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go back to basics, Now that the engine is off, pull the shroud and the head off the engine. If you had done a basic tune up in the past and it was running (and you still have fuel, spark, and compression) I would venture to say that maybe something happened with the timing as a start point. If it was running after the tune up but did some popping or backfiring it may have knocked the keyway loose and took it out of time or something to that effect.
Remember that when you did the points the first time you had to pull some head bolts loose to get the cover off, you just loosened up part of the head on a 45 year old engine with possibly the original crusty flattened out head gasket, so chances are good it would start to leak.
The head gasket needs replaced, so pop the head off and get a good look at the cylinder wall and valves at that point to determine if its all carboned up, or something passed through, etc. Now onto the flywheel, Is it still tight? when you remove it how does the keyway look?
The only aluminum flywheel Tecs (60's early 70's) that I have ever found to have a sheared or messed up keyway have been Fox HS40's on the 10" wheeled bikes......I am guessing it stems from the carb tuning. They are a finicky carb that does not like any type of debris in the system. so they get out of tune or dead spots and maybe cause a good backfire......keyway gone.
start there :thumbsup: Of course anytime you have the flywheel off its a good idea to give another inspection of the points, gap setting and that all the wiring is staying clear of the moving flywheel etc...
So even if you find something simple I would suggest (if you did not do it before) replacing the intake gaskets and the exhaust gaskets as well at this point along with the head gasket.
Remember that when you did the points the first time you had to pull some head bolts loose to get the cover off, you just loosened up part of the head on a 45 year old engine with possibly the original crusty flattened out head gasket, so chances are good it would start to leak.
The head gasket needs replaced, so pop the head off and get a good look at the cylinder wall and valves at that point to determine if its all carboned up, or something passed through, etc. Now onto the flywheel, Is it still tight? when you remove it how does the keyway look?
The only aluminum flywheel Tecs (60's early 70's) that I have ever found to have a sheared or messed up keyway have been Fox HS40's on the 10" wheeled bikes......I am guessing it stems from the carb tuning. They are a finicky carb that does not like any type of debris in the system. so they get out of tune or dead spots and maybe cause a good backfire......keyway gone.
start there :thumbsup: Of course anytime you have the flywheel off its a good idea to give another inspection of the points, gap setting and that all the wiring is staying clear of the moving flywheel etc...
So even if you find something simple I would suggest (if you did not do it before) replacing the intake gaskets and the exhaust gaskets as well at this point along with the head gasket.
Thanks for all the advice. I will give it a go. I will try to post some pics after I pull the head to see what you guys think. I did notice a while back that I could not get it to fire at all, so I back tracked my steps and pulled the fly wheel off, inspected to see if i missed anything, didn't see anything that looked wrong, put the flywheel right back on and it fired up? Rode it for about 20 minutes, it died, and has not started again since.
Could that be something to do with the coil/magneto.
Could that be something to do with the coil/magneto.
Ok. So last night I got out in the garage and went to work! This is what I have found!
Points look great, confirmed gap @ .020.
Valves were all carboned up! Will clean, lap, and re install them.
Condenser wire has been rubbing on flywheel, will re position it.
Piston and sleeve looked great, no grooves or scoring at all.
I cleaned up the top of the head/piston and removed all carbon build up.
The flywheel key was definitely sheered off, will replace it.
I am going to clean everything up good and replace all the gaskets as well.
Is there anything else I may need to do while Ive got it apart.
Thanks
Points look great, confirmed gap @ .020.
Valves were all carboned up! Will clean, lap, and re install them.
Condenser wire has been rubbing on flywheel, will re position it.
Piston and sleeve looked great, no grooves or scoring at all.
I cleaned up the top of the head/piston and removed all carbon build up.
The flywheel key was definitely sheered off, will replace it.
I am going to clean everything up good and replace all the gaskets as well.
Is there anything else I may need to do while Ive got it apart.
Thanks
Replace the head gasket when you put it all back together. Aside from that and lapping the valves after cleaning, I think you'll be good to go. Be sure you torque the flywheel down tightly so you don't shear or bend any more keys. I ended up going through about 10 on my HS40 build because I made a rookie mistake of putting them in backwards :doah: But we learn from our mistakes. At least, I hope so :laugh:
Keep us posted
By the way, I am fairly certain your condenser is upside down. That little arm on the left side in the picture should be against the stater plate, near the coil. Not just floating around out there. It'll help keep the wires held down and away from the flywheel when properly seated
Keep us posted
By the way, I am fairly certain your condenser is upside down. That little arm on the left side in the picture should be against the stater plate, near the coil. Not just floating around out there. It'll help keep the wires held down and away from the flywheel when properly seated
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yea the condensor is installed backwards like cap said. I would just say when putting it back together to make sure flywheel seats good, kinda hard to do on the lighted ones sometimes due to all the magnets, and make sure the recoil cup gets seated good. looks like the 3 humps are wore down on the face of the flywheel like the cup did not get seated right at some point in its life. Should have a bellville/coned washer and a lightly stepped flywheel nut (the step centers the washer) to seat it all together, If its missing the washer or anything like that I would be a good idea to get that stuff.
That engine is actually pretty clean on the top end :thumbsup:
That engine is actually pretty clean on the top end :thumbsup:
Ok. So I repositioned the condenser and wires. Cleaned and lapped the valves, waiting on spring compressor to install them. I ordered gaskets, flywheel key, nut, and washer. I also ordered a new thrust washer for the shaft side. I hope to have it all back together by this weekend if my stuff comes in. Is there a proper torque spec for the flywheel nut and head bolts?
Thanks again for all the help. I'd be lost without this forum!
Thanks again for all the help. I'd be lost without this forum!
Well....Thanks to all of yall's help and a little sweat, cussin, and knuckle bustin! :censure: I'm back in action! Got everything cleaned up, new gaskets, fresh fuel, re set points, repositioned condenser, new flywheel key, nut, and washer, fresh oil, new chains, cleaned and lapped valves,:grind: she is growlin like a gremlin!
I really appreciate all the help and much needed guidance!
I really appreciate all the help and much needed guidance!