Should this chain be tight or loose? This is my first build on small engine. I have excess just laying on top for pic. Am I running it right? Thx

jspbtown

Active Member
#2
Thats way too lose. Do you have slots to slide the motor or are you supposed to have a tensioner? And what is that on your clutch? And it looks like your engine is crooked
 

I74

Well-Known Member
#3
That's ''scary'' loose, & an accident waiting to happen !! :eek:

Also,,
is there any teeth left on that back sprocket, or are the teeth just covered in black grease ??.. Can't really tell for sure in the pic.

Lastly,,
Don't think you need that big of back sprocket with the 212,, you are just going to potentially flip yourself over backwards.

What's the tooth count on the clutch & back sprocket ??
 
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SAS289

Well-Known Member
#4
In the picture the engine isn't bolted down. It looks like he has the chain on there just to get the idea of what position to bolt down the engine.

Looks like that will end up needing a chain roller to clear whatever that bar underneath is. Even with a smaller sprocket.
 
#6
That's ''scary'' loose, & an accident waiting to happen !! :eek:

Also,,
is there any teeth left on that back sprocket, or are the teeth just covered in black grease ??.. Can't really tell for sure in the pic.

Lastly,,
Don't think you need that big of back sprocket with the 212,, you are just going to potentially flip yourself over backwards.

What's the tooth count on the clutch & back sprocket ??
The count is 53 or 54
 
#9
Thank you, I’m new to small engines. I’m a computer guy lol
Welcome...and no worries...most the pros didn't even notice it..lol. Your chain should have about a 1/2 of deflection. Meaning you can move it up and down about a half inch basically. That is generally perfect tightness for a chain. And the biggest part is to make sure it is to make sure the sprockets line up straight. Meaning the chain needs to be straight as possible.
 

I74

Well-Known Member
#10
The count is 53 or 54
Boy , that tooth count sure seems larger than that in the pic,, but it is really hard to see...

Count that & the clutch teeth for us, ok?
Use a Sharpie or paint, ''not black'',, & just mark the 1st. tooth on each sprocket,, & count around until you get back to that mark.
You can set the bike on a milk crate or something, so you can turn the wheel ect.
 
#11
I
Boy , that tooth count sure seems larger than that in the pic,, but it is really hard to see...

Count that & the clutch teeth for us, ok?
Use a Sharpie or paint, ''not black'',, & just mark the 1st. tooth on each sprocket,, & count around until you get back to that mark.
You can set the bike on a milk crate or something, so you can turn the wheel ect.

its 8.5 inches in diameter, I’m about to count teeth for you

Thats way too lose. Do you have slots to slide the motor or are you supposed to have a tensioner? And what is that on your clutch? And it looks like your engine is crooked
I have slots but I found one online and it didn’t have a tensioner factory wise but I didn’t pay any attention to the diagram of the belt and how it was ran.
 
#13
Boy , that tooth count sure seems larger than that in the pic,, but it is really hard to see...

Count that & the clutch teeth for us, ok?
Use a Sharpie or paint, ''not black'',, & just mark the 1st. tooth on each sprocket,, & count around until you get back to that mark.
You can set the bike on a milk crate or something, so you can turn the wheel ect.
The count is 54
 

MJL

Active Member
#16
Bolt the engine down loosely and slide it all the way back in the slots. Then cut your chain (by driving out the pin in the apropriate link) to the shortest length that still fits easily. Then, after you put the chain on, slide the engine forward until the chain is snug, but not ridiculous, and tighten the bolts. I like to go until there is no "jiggle" in the chain. As the chain wears, it will get longer (especially in the beginning) and you will need to retighten occasionally.

What model is your mini? Can you find orginal stock pics that might show a bracket to facilitate sliding the engine forward?
 

I74

Well-Known Member
#17
That's pretty much what I figured.
Gear ratio is 5.4 -1

That bike with a 5.4 - 1 ratio & 212,, is going to be a handful ....

Have you ridden powered bikes much, like dirt bikes or Motorcycles ect. ??

If it was me, I would go with an 11t clutch sprocket to tame it down some out of the hole.
That would give you a ratio of 4.9 - 1

12t sprocket would even tame it down more, & give you a ratio of 4.5 - 1.

If you weigh under ''say'' 180lbs.,, the 12 tooth would probably be fine,, plus safer. ;)
 
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#18
Bolt the engine down loosely and slide it all the way back in the slots. Then cut your chain (by driving out the pin in the apropriate link) to the shortest length that still fits easily. Then, after you put the chain on, slide the engine forward until the chain is snug, but not ridiculous, and tighten the bolts. I like to go until there is no "jiggle" in the chain. As the chain wears, it will get longer (especially in the beginning) and you will need to retighten occasionally.

What model is your mini? Can you find orginal stock pics that might show a bracket to facilitate sliding the engine forward?
It’s a 75-76 no brand on it. Just Sears simpsons Roebuck co sticker. Now when I had it all right and gave it gas, the clutch wouldn’t turn and make the bike go, do you know why that is?
 
#19
That's pretty much what I figured.
Gear ratio is 5.4 -1

That bike with a 5.4 - 1 ratio & 212,, is going to be a handful ....

Have you ridden powered bikes much, like dirt bikes or Motorcycles ect. ??

If it was me, I would go with an 11t clutch sprocket to tame it down some out of the hole.
That would give you a ratio of 4.9 - 1

12t sprocket would even tame it down more, & give you a ratio of 4.5 - 1.

If you weigh under ''say'' 180lbs.,, the 12 tooth would probably be fine,, plus safer. ;)
for some reason I got it all right chain wise and the clutch wouldn’t make the bike go when I gave it gas
 
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