First ever build. Avalon

[JackieJak]

Well, after a year of blood, sweat, and tears, and especially money. Along with lurking on the forums. I finally (nearly) completed my build.

Runs great but still had hiccups. The 415H chain on the rear sprocket likes to go between the sprocket and the spokes. So I used the stock tensioner (not on yet fully) to keep it lined up. Was debating on going #41 or just save up and go all out with a jackshaft kit. So far I clocked it at 25mph max with that 16:1 mix.. wich I found out kills power, so now running 40:1 for now.

 

[bluegoatwoods]

It's a nice looking bike. I've pondered building on that platform before simply because the rear suspension would be a nice feature. But I've held back because of the issue of engine chain tension.

And it sounds as though that might be your trouble. Going with a 41 chain never hurts. But I doubt if it'll get rid of the trouble completely. But maybe a spring mounted tensioner?

 

[bailsafe]

Beautiful build, always loved the Avalon personally. The stock chain tensioner helped me out with keeping my chain out of the spokes. Hope you can get the chain jumping issue solved, never hurts to try the #41.

 

[JackieJak]

It's a nice looking bike. I've pondered building on that platform before simply because the rear suspension would be a nice feature. But I've held back because of the issue of engine chain tension.

And it sounds as though that might be your trouble. Going with a 41 chain never hurts. But I doubt if it'll get rid of the trouble completely. But maybe a spring mounted tensioner?

Been thinking it, and possibly bend one to realign the chain. Along with redoing the intake do make it breathe more easily. Also anything to get more bottom end power. Especially with these hills here.. very steep. Plus with a shift kit later on, convert that power. Plus, has anyone tried to do an electric start for these 2-strokes?

 

[2door]

Welcome to the forum and congratulations on your first build.

A couple of suggestions: The chain tensioner should not be used to "guide" the chain onto the sprockets. It is a 'tensioner', not a 'guide'. If the drive and driven sprockets are properly aligned you should not have to guide the chain.

Any movement in the rear wheel, up or down is going to impact chain tension to some degree. For an unsuspended rear wheel we recommend 1/2" to 3/4" of slack. You might have to experiment and do some reading here on full suspension builds by other members to see how they have addressed the rear wheel movement issue. I know some have gone to a spring loaded tensioner but try to avoid those if at all possible.

A good industrial quality #41 chain is superior to the kit chain. Kit chains are notorious for fast wear, kinks and rough spots that might be contributing to your chain derailing problems. #41 chain is available through Grainger, Tractor Supply, most any industrail supplier and even some Ace Hardware stores carry it.
Good luck.

Tom

 

[JackieJak]

Welcome to the forum and congratulations on your first build.

A couple of suggestions: The chain tensioner should not be used to "guide" the chain onto the sprockets. It is a 'tensioner', not a 'guide'. If the drive and driven sprockets are properly aligned you should not have to guide the chain.

Any movement in the rear wheel, up or down is going to impact chain tension to some degree. For an unsuspended rear wheel we recommend 1/2" to 3/4" of slack. You might have to experiment and do some reading here on full suspension builds by other members to see how they have addressed the rear wheel movement issue. I know some have gone to a spring loaded tensioner but try to avoid those if at all possible.

A good industrial quality #41 chain is superior to the kit chain. Kit chains are notorious for fast wear, kinks and rough spots that might be contributing to your chain derailing problems. #41 chain is available through Grainger, Tractor Supply, most any industrail supplier and even some Ace Hardware stores carry it.
Good luck.

Tom

Yeah if properly, sadly nothing ever goes perfect for me and gotta make do with what i got. Also I did find a 41 chain that's nickle plated online.. Plus there's only truevalue around here after Ace closed. :/

 

[JackieJak]

I had a thought regarding chain. I was looking and found KMC K910. Wonder if that would be a decent upgrade vs. a nickle plated 41.

 

[Earbiter]

I'm just spitballing here, but does that rear spring have a tensioner? Because if it does, then you could just tighten it to remove some of the chain slack issue. But of coarse that won't remove the issue, just limit it. Also it will make for a less comfy ride.

 

[JackieJak]

Like you said. a less comfy ride. Plus it defeats the purpose of the bike itself.

 

[JackieJak]

Well crap, I accidentally tightened the bolts to the exhaust and now it's stripped. Don;'t feel right riding it with the exhaust leaking out. So looks like I'm gonna have to wait until I can re-thread with some 7-8mm.

 

[2door]

Another good argument for buying and using a good quality torque wrench. Over tightening is the most common problem many builders have with the Chinese 2 stroke engines and kits.

Hint: If you are having exhaust leak issues you might want to check the gasket surface of the exhaust flange. They are all usually warped from the welding process which makes for a poor seal even when tightened (torqued) sufficiently. A good automotive grade of 1/8" thick gasket material will also help but the flange needs to be flat for a good gasket seal.

Clean the gasket surface of the exhaust pipe flange then 'paint' it with Magic Marker or machinist dye then run it over a sheet of course sandpaper laying on a flat surface such as a piece of glass. You'll quickly see the high and low spots that need to be sanded or ground flat.

About 60 inch pounds of torque is all that is required for those 6mm fasteners. Good luck.

Tom

 

[JackieJak]

Nah, the exhaust leak is caused by the loose exhaust pipe thanks to stripped screws; and yeah, I really need to look into getting a torque wrench. I also have a little idea of making the 2 stroke electric start...

 

[Jasoninwisconsin]

built one of these bikes but i used a friction drive setup and it worked really well.

 

[JackieJak]

Awesome, thought it does make me wonder. If it would be possible to put in a 49cc 4stroke into this. From what I've seen if you make an intake manifold to them and just keep the carb level, you can move the engine nearly any way you want.

 

[JackieJak]

Little update on it. Seems with the way the carburetor set up, it's not getting enough air. I had to set the needle on the NT to max lean (has 4 settings on it and was already on next to leanest) and had to remove the filter to even get it to stop 4 stroking. Think what I may have to get next is a reed valve to have a short intake and an expansion pipe put on. Especially since regular 2 strokes have those anyways. Plus with these steep STEEP hills. I barely make it up some before it stalls on me.

 

[JackieJak]

Little bit of an update. I installed a reed valve to stop the blowback of fuel/oil from leaking from the carb.. Worked great until something else came up. One of the mounting bolts broke off.