Tecumseh mounted, but chain acting screwy.

mmisterbungl

mmisterbungl

New Member
#1
#1
So I put a new (old) Tecumseh on my Trail Horse today. I'm a little confused as to what's going on. When I mount the engine and tighten down the bolts to the desired chain tension, everything looks fine. Until I start rolling the bike. FYI - this is a direct drive set up...no j/s. The chain will get super loose, then super tight in a cycle of such. My first thoughts were that the engine was mounted slanted (one side slightly more at an angle than the other)...not the case. I got everything straight, and still doing the same thing. Then I tried lengthening the chain so that I was on a different part of the surface of the engine plate....all the way forward in this case. Still doing it.

Thoughts, experiences with the same???? Anyone....:shrug:
 
bandit 40

bandit 40

Active Member
#5
#5
Yeah ,like what was mentioned above, time to replace:thumbsup:. I know that if the chain is got a spot where the links dont bend around the sprocket, it will also get tighter as it rolls or your sprocket is not centered . And after cheap chain or chain with a low tensile strength is stretched out, it will sometimes get that twist or keep jumping the sprocket.
 
mmisterbungl

mmisterbungl

New Member
#6
#6
Thanks guys, but the chain is brand new. In fact I tried two new chains right out of the box. And the sprocket is also Brand new. So i'm assuming the sprocket is not true due to the spacer maybe.
I think someone made the spacer that goes between the sprocket and wheel. HEre's a pic of it.




and it's on these wheels

 
C

C9H13NO3

Active Member
#7
#7
mmisterbungl said:
So I put a new (old) Tecumseh on my Trail Horse today. I'm a little confused as to what's going on. When I mount the engine and tighten down the bolts to the desired chain tension, everything looks fine. Until I start rolling the bike. FYI - this is a direct drive set up...no j/s. The chain will get super loose, then super tight in a cycle of such. My first thoughts were that the engine was mounted slanted (one side slightly more at an angle than the other)...not the case. I got everything straight, and still doing the same thing. Then I tried lengthening the chain so that I was on a different part of the surface of the engine plate....all the way forward in this case. Still doing it.

Thoughts, experiences with the same???? Anyone....:shrug:
Click to expand...
Hey mmisterbungl, I have about 40 feet of chain that I don't need. I could cut you off a peice and send it to you. Just pay shipping.
 
bandit 40

bandit 40

Active Member
#9
#9
I have purchased bad chain before, where it had a slight twist :censure:,not that yours is bad ,but not impossible. You could remove it lay it out on a flat surface and check it.:shrug: worth a try..
 
derekbmn

derekbmn

#10
#10
With out a doubt the rear sprocket is not concentric with the wheel. I have ran into this several times and it (as you have found out) is ALWAYS due to the use of a spacer(s) .

Here is something to try,first get the bike up off the ground....Then with everything together rotate it until the chain tightens/binds up...leave it there and carefully loosen the bolts (slightly), that attach the sprocket to the spacer. This will pull the sprocket forward slightly (you may not even see it move...but it will)
Tighten the bolts and see if the condition improved...it may take several times, but it will help.
The chain tension may need to be re-adjusted after that.

Give it a try.
 
delray

delray

Well-Known Member
#11
#11
also what kind of bolts are you using? do they fit nice and snug in the rims holes and spacer. keeping everything center when tighten up.
:rolleyes:
 
S

supernova

Banned
#12
#12
That's for sure not a Manco spacer which is what your problem may be. The spacer you showed looks good but are the holes really allowing the bosses to clear inside? I have mancos in both 5" & 6" and have the correct spacers and the sprockets run true. Spin it in place witout the chain and look at it, you'll know quickly if it's good or not. Could be an inferior quality chain that's binding and stretching as previously mentioned, I bought a 10ft box of crappy chain at the mower shop and had to take it back for nearly the same reason. You'll get it figured out!:thumbsup:
 
125ccCrazy

125ccCrazy

Well-Known Member
#13
#13
take the chain off, clamp a pointer on the frame so it is barely touching the tooth on the sprocket...spin the wheel slow, if the sprocket is running out of round the pointer will either catch a tooth or you will be able to see between the pointer and the teeth as the sprocket drops...As mentioned earlier, if the sprocket is out of round you may be able to just snug the bolts and using the pointer take a mallet and tap the sprocket until it starts running true...
 
mmisterbungl

mmisterbungl

New Member
#14
#14
Give the men some cigars. Right on point.
It seems that the whole wheel as well as sprocket and spacer is out of round somehow. I will definitely disassemble sometime today and look closely. In the second video you can see the tire is also showing signs of wobbling. could the axle mount tabs be the culprit if the WHOLE thing is wobbling? Thanks again for everyone's input.

YouTube - Sprocket
YouTube - Wheel wobbling
 
jeep2003

jeep2003

#17
#17
it looked to me like the spacer and sprocket were moving but not the rim. The tire could be too but thats likely its own issue. If the rim runs true than its not the axle or bearings
 
mmisterbungl

mmisterbungl

New Member
#18
#18
jeep2003 said:
it looked to me like the spacer and sprocket were moving but not the rim. The tire could be too but thats likely its own issue. If the rim runs true than its not the axle or bearings
Click to expand...
Jeep, you are correct. I took a closer look after I got home from work yesterday, took off the bolt, bearings and sprocket....all were straight and unwarped. I did see that the wheel was spinning true. It's definitely that stupid spacer. Someone did a bad job on making sure it was symmetrical and straight all the way around.

At this point, I need to find one of you guys (probably YellowHand :shrug:) that I can send this spacer to and have you replicate it to perfection. Or if someone knows a homemade trick to make some sort of spacer(s) that would be ideal.
 
derekbmn

derekbmn

#20
#20
Have you considered not using this spacer and using 3 individual spacers ?? Give me some dimensions (length the spacers would need to be,bolt size) and I may be able to help you out.
 
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