Swap 110cc for Predator 212?

[seethesun]

NP. I didn't want to rush you, but my son has been giving me a (not so) subtle reminder that the kart isn't done. So I thought I would pass that along.

 

[firemanjim]

*5800 Corporate Dr. #A14,

* * * * Houston, TX 77036

Tel: (713)588-1681

* * * * M-F, 9:00 am - 5:00 pm, CST
Call that number, tomorrow. Ask for Nick. Tell him what you're looking for. He is the tech guy at that chinese parts house. If they don't have it, he might be able to get it or point you in the right direction. In person, he is very knowledgeable.....
I can find a 125cc auto, but it's not a Lifan. It is, however, a popular engine. That PCC company. The engine identification is done exactly like Lifan, which is odd......

 

[seethesun]

Update: So this did get up and running before Christmas. However, now I am running into an issue with sprockets.

We live on land that has a bit of an incline. Often times I have to give my son a little push when he's going up hill from a standstill (or if he slows too much before heading back up).

The ratio is 2.5 (38:15). I have been looking for a 10 tooth sprocket. My chain is a #40, but I can't find a 10 tooth in a #40. Actually, I can't even find a 15 tooth. So it makes me wonder if this is a #40 sprocket. Would a #40 chain work on a #428 sprocket?

If so, I found this for a 10T. The one in my picture has the screw holes, but they aren't used.

http://www.ebay.com/itm/NEW-20MM-MO...Sprocket-/121607224394?_trksid=p2054897.l4275

FYI - I have considered increasing the size of the driven, but am having equal issue finding a sprocket. It's a 3 hole and there is not much space (maybe 3/4") between the current sprocket and the guard.


Thanks for any insight.

 

[Denny]

No that sprocket will not work! Go to Tractor supply or Ace hardware they have them or can get them.

Denny

 

[seethesun]

Thanks Denny. I thought about TS, but did not remember them having sprockets with 6 splines and none of the sprockets I found on their website specifically state it (though their website descriptions aren't the greatest). I will check them out today. I didn't think about ACE, there is one of those close as well, though their site doesn't show any sprockets.

With that said, I bought the engine I have new. It came with an a 13T sprocket. I forgot I even had it because I couldn't use it due to the layout requiring an extended shaft. Well, I stumbled upon it last night and it's stamped with a 428-13T.

So it got me to thinking, considering I can't seem to find a 15T in a #40 20mm or 6 splined, maybe the one I was using was a 428? However, there isn't a stamp. Is there a way I can measure to tell? The thickness of a 40 & 428 are the same. Any idea on the spacing between the teeth? Why would a 428 not work?

Thanks.

 

[firemanjim]

ANSI Standard Chain Dimensions

Chain No. Pitch Roller Diameter Roller Width Sprocket thickness Working Load
25 1/4" 0.130" 1/8" 0.110" 140 lbs
35 3/8" 0.200" 3/16" 0.168" 480 lbs
40 1/2" 5/16" 5/16" 0.284" 810 lbs
41 1/2" 0.306" 1/4" 0.227" 500 lbs
50 5/8" 0.400" 3/8" 0.343" 1400 lbs
60 3/4" 15/32" 1/2" 0.459" 1950 lbs
80 1" 5/8" 5/8" 0.575" 3300 lbs
Bicycle and Motorcycle Chain Dimensions

Chain No. Pitch Roller Diameter Roller Width Sprocket thickness
Bicycle, with Derailleur 1/2" 5/16" 1/8" 0.110"
Bicycle, without Derailleur 1/2" 5/16" 3/32" 0.084"
420 1/2" 5/16" 1/4" 0.227"
425 1/2" 5/16" 5/16" 0.284"
428 1/2" 0.335" 5/16" 0.284"
520 5/8" 0.400" 1/4" 0.227"
525 5/8" 0.400" 5/16" 0.284"
530 5/8" 0.400" 3/8" 0.343"
630 3/4" 15/32" 3/8" 0.343"

EDIT
You shouldn't have any problems using #40 chain on a #428 sprocket. The pitch is the same, thickness is the same.......

 

[seethesun]

Thanks. I found that chart also and the only difference I could see was the roller diameter, but didn't know if the difference was going to have a major adverse affect.

Is going from 2.5 to 3.8 a big change? Or will it be noticeable? I see articles talking about high and low gear ratios, but there is never any context. What's considered high, what's considered low? Or how much of a impact a certain change can make.

I understand circumstances can be different based on the terrain and weight of the kart/passengers.

Thanks again.

 

[firemanjim]

That would be a very noticeable difference. Try the 13 tooth you have. Even that, will be a noticeable difference. More than likely, you won't need to give him push anymore.
As far as the diameter of the roller goes, it's about a 4 hair difference. Maybe not the best way to go, but I don't see it not working or be so detrimental that it's not feasible.....

 

[Denny]

Sun,
Oops! I feel like a idiot. I totally spaced the fact that you have basically a clone ct70 engine. :toetap05: I think the sprocket you picked out may work. On that type of engine 13 tooth primary is the smallest sprocket they make. Lets put it this way I have never heard of a smaller one. Please forgive me and do not have me shot at dawn.

Denny

 

[seethesun]

That would be a very noticeable difference. Try the 13 tooth you have. Even that, will be a noticeable difference. More than likely, you won't need to give him push anymore.
As far as the diameter of the roller goes, it's about a 4 hair difference. Maybe not the best way to go, but I don't see it not working or be so detrimental that it's not feasible.....

Thanks. Unfortunately, the 13 tooth won't work because the ID is too small. The crankshaft runs into a ujoint, which another splined shaft fits into. However, that second splined shaft graduates to a 20mm, too wide for the 13 tooth that came with it.

I ordered the 10 tooth before I saw your post. Of course, the only place I could find it was on eBay or Alibaba in the UK or China, so it's going to take some time to get here. The 13 tooth I can find in the US, so I might go ahead and order since it's cheap and it should arrive faster, see if it works.

Thanks for the input and no worries Denny.

 

[seethesun]

I am trying to change a gasket because of an oil leak. However, I am stuck at getting the cam gear off. It's unbolted, but I can't get it off, chain is tight.

Researching, I found an article and video talking about a tensioner, but those looked like slightly different engines and if mine has a tensioner, I have no idea where.

I watched a different video of someone changing valves on a similar engine and they were able to take the gear off just by needle nose pliers in the bolt holes, after bolts were removed of course. It didn't show any adjustment to a chain tensioner.

I have read in another thread where someone said a bolt on the bottom of the engine (looks like a drain plug) is the tensioner. This pic is of one I found that's similar to mine (ignore the annotation). The right is the one said to be the tensioner. However, I loosened it to the point of accidentally removing it, and a spring popped out, but the chain never loosened.

Any ideas? Thanks