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  #6691  
Old 12-28-2013, 01:14 AM
crassius crassius is offline
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Default Re: what did you do to your motorized bicycle today?

that spark plug seems to have a bad compression ring, or maybe the threads are bad in the head - oil spatter on chain guard could be either carb or muffler
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  #6692  
Old 12-28-2013, 09:25 AM
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placidscene placidscene is offline
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Default Re: what did you do to your motorized bicycle today?

I was wondering about the oil under the spark plug. I do have a hard time not cross threading it when I put it in. I guess the threads are damaged.

Good excuse to buy an upgrade... lol any suggestions?

Also could the leak at the plugs cause the 4 stroking?
The fuel is definitely coming from the carb. And I already check the float, it floats.
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  #6693  
Old 12-28-2013, 11:41 AM
crassius crassius is offline
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Default Re: what did you do to your motorized bicycle today?

the plug leak could cause several things that will rob you of power - it needs fixing, so do so & see

head comes off easily for sleeving or helicoiling if you don't have easy access to another head

fixing this might even reduce the spit-back from the carb
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  #6694  
Old 12-29-2013, 03:04 AM
MEASURE TWICE MEASURE TWICE is offline
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Default Re: what did you do to your motorized bicycle today?

I ordered a crankcase oil breather assembly to see if my 5 years ago refurbished Briggs 4 stroke 3hp engine has less smoke out the muffler. Its not much, but I expect it could be better. There has been very little run time on the engine till now. It had the valves and seats cut and length of the valve compensated. The rings also replaced, so it has good compression and starts right up no problem.

I know the older cast iron engines have parts that are not in a crimped metal case. With those you can see the spring inside and replace it with another new one I'd bet. Those type there is no return tube to the air-filter / carburetor. They just vent the oil mist down the side of the engine.

This 70's era 80202-0430 aluminum Briggs engine, you have to replace the whole breather. I have a couple of extra air-filters that I will install if I see that the one in there now got mucked up from the worn breather spring not working properly and the return tube sprayed a lot of oil mist on the filter.

MT
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  #6695  
Old 12-29-2013, 03:08 AM
MEASURE TWICE MEASURE TWICE is offline
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Default Re: what did you do to your motorized bicycle today?

Quote:
Originally Posted by crassius View Post
the plug leak could cause several things that will rob you of power - it needs fixing, so do so & see

head comes off easily for sleeving or helicoiling if you don't have easy access to another head

fixing this might even reduce the spit-back from the carb
You could bring it to a machine shop to install the Helicoil if it seems to be economical and you don't want to buy the special sized drill bit and Helicoil insertion tool and coil insert. I can say once those are installed I have never had a problem ever with cross threading again.

There are other non-spring type inserts, but my thought on those is there not worth using as they are as soft as the white metal they cast the head with.

MT

Last edited by MEASURE TWICE; 12-29-2013 at 03:11 AM.
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  #6696  
Old 12-29-2013, 04:16 PM
BonusParts BonusParts is offline
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Default Re: what did you do to your motorized bicycle today?

I did this a couple days ago. pic links to the other few pics in my rebuild thread

Attached Images
File Type: jpg 1.jpg (143.4 KB, 137 views)
File Type: jpg 2.jpg (165.5 KB, 200 views)
File Type: jpg 3.jpg (246.6 KB, 147 views)
File Type: jpg 4.jpg (151.0 KB, 133 views)
File Type: jpg 5.jpg (141.0 KB, 139 views)
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  #6697  
Old 12-29-2013, 08:13 PM
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truckd truckd is offline
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Default Re: what did you do to your motorized bicycle today?

Just a little secret before paint casing if you have a dremel ? hone out the bolt hole so that the bolts don't pull the paint off the edges.

Everything looks great! keep up the good work I'll have to fallow this thread
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  #6698  
Old 12-29-2013, 09:55 PM
crassius crassius is offline
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Default Re: what did you do to your motorized bicycle today?

yes, and I put a dead spark plug with the top broken off in the head too - guards the hole & makes a handle
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  #6699  
Old 12-29-2013, 10:57 PM
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Danschutz Danschutz is offline
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Default Re: what did you do to your motorized bicycle today?

I haven't even seen my bike in a week or so, been super busy at the shop. I did however visit a good friend and old motocross riding buddy. The man gab evolved to motorcycles and well long story short he gave me a brand new set of Renthal bars off his 450. They are the stock bars and he doesnt use them. He's sponsored by some companies and gets bars when needed.

I'm also getting the new exhaust off his kids 65cc just as soon as the fmf pipe arrives. Good timing I guess lol.

Here are the bars, I also have the throttle that I left in my truck by accident. That's a big chain guard that I'll try and fit somewhere as something.



Dan.
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  #6700  
Old 12-29-2013, 11:09 PM
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xseler xseler is offline
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Default Re: what did you do to your motorized bicycle today?

I did some 'tweaking' on my home made "Frankenstein" exhaust. It's not quite finished yet, but it's looking a whole lot better than it did. I'm still undecided about the expansion chamber that's on the bike now ---- it looks great, but I think that I like the sound of the one I made. Who knows? I might sell the expansion chamber and apply the fundage to my upcoming shift kit.............
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