Tensioner issue solved for $5 and a hacksaw

After toying with my first engine and now on my second, here are some observations that will help the noob (i.e. people like me who own just a few tools and aren't machinists).

~ Start with the sprocket, because it is the most tedious if done right. Get all the hardware set as perfectly as possible tightened just enough so it does not move. Flip your bike upside down, put the wheel in the holder and spin. Look good? Remove it and in a sort of north south east west pattern, tighten each a little in turn until it's good to go.

~ Put the wheel on and tighten it just enough to hold it in place.

~ Next flip the bike over and mount the engine tight enough so you can wiggle it left to right and put the chain on. Move the engine to a point that, when the chain length is eyeballed from the rear of the bike it's as straight as it can be. tighten engine mounts, trying to maintain this position. These two steps are your starting point.

~ Add the factory shipped tensioner, but don't tighten it all the way, maybe 60%.

~ Prior to all this you'd have gone to the home depot hardware section and purchased a 4 ft piece of pre-drilled flat steel and cut off an appropriate length. Add this from your rear wheel to your roller mount (I took out the bike wheel washer and used this as the new washer).

~ Tighten the wheel. Strange, but it makes a big difference; Tighten the the nut on the right side (Bike chain side) and then the left.

~ Finally, tighten the tensioner.

Thanks so muck to Bikeguy Joe and Norm for their insights.

hth

@ decoherence - I did look at all of the threads you point out and there are some really fantastic solutions, but I wanted something that was fast and effective, not to mention cheap. I believe you are correct about the 2-point system being the best.

With my solution there is some flex, but just a little. I did an experiment for only like 50ft, where I loosened the tensioner bolts a little and it held. At this point, I've only put about 15 miles on my rig and all looks good.

My biggest concern, and I should have stated this in my original post, is that over time the engine torque and tensioner will win out. Regular PMCS (Preventive Maintenance Checks and Service) should catch this beforehand.

Any other advice you can provide is welcomed. After all, I am a noob

Do you have any pics of your setup?

wayne z said:

Here's my easy fix.
View attachment 41208

Some haso have adjusted the motor chain tight without the idler then installed the idler on the pedal chain. I've had to use the idler on the motor chain on all my bikes to keep the chain from rubbing the frame.

Click to expand...

By the marks on the rear tire, looks like your idler leaned in causing the chain to rub. Solution looks good, although I can't make out the materials and anchor hardware used.

Could you describe why you decided on this fix and how you implemented it? It seems that the idler ruins most newbies' motor bicycling experience and any insight would help.

When your idler careens into your spokes its gotta be like buying a brand new car and getting T-boned just as you pull off the lot!

BTW - I've been using the word 'tensioner' vs 'idler. Which is the correct term and why?

So, today I had the opportunity to fix a guy's bike (bad carb and fried mag). Thing is he had no idler, just a shortened chain. I'm building a second bike and might try this. Where can I buy a chain break tool; standard bike chain tools don't work.

Also, this is a standard chain included with the kit; How do I know what the size is and is there a decent guide to chains?

OK, now my ignorance is apparent. I know what a shim is, but what does it mean to "shim" the engine?