Chain been stuck on the engine

Daquino · Mar 7, 2016

Hello , I'm from Brazil and I'm not finding an answer to my problem here.
My English is not very good so sorry if any trouble understanding what I mean , I'll give my best.

With the bike at high speed heard a scratch from the chain, I came home in low speed and found a scratch on the left engine cover, see the video.

https://www.youtube.com/watch?v=ynmWZYxFRqw

I lined up the engine that was not centered and stretched the chain, going out again with the bike the scratching appeared again , but as can be seen in the next video, the chain brake when I push the bike back.

https://www.youtube.com/watch?v=Sd--P_zbkH4

Note: going back and forth a few times as the last video makes the scratch stop, but just pick up high speed again and the scratch happens again.

What do you think can be?

I tried opening the right side cover where is the gears of the clutch, but when removing the screws the cover seems to be stuck , how to remove safely?

Thank you for the help.

KCvale · Mar 7, 2016

Just cut a notch out of your left cover where the scrape marks are.
This is common in some engines that were meant for 410 single speed chain and you are using 415 or the even heavier 41.

Daquino · Mar 7, 2016

KCvale said:
Just cut a notch out of your left cover where the scrape marks are.
This is common in some engines that were meant for 410 single speed chain and you are using 415 or the even heavier 41.

I'll cut out the area where is rubbing, but you don't believe that can be a problem in the gears on the right ? Little lubrication perhaps?

Thank you!

2door · Mar 7, 2016

Daquino said:
I'll cut out the area where is rubbing, but you don't believe that can be a problem in the gears on the right ? Little lubrication perhaps?

Thank you!

The gears need to be lubricated but you need to be careful. They require only a small amount. Not much more than a glob of grease the size of a pea and spread around a little over the gear teeth.

However, I doubt that a lack of grease on the gears is causing your problem. I suspect your chain tension is not right, too loose, and the chain is binding up on the engine drive sprocket. You'll want 1/2" to 3/4" of slack. More than that and the chain can bind and/or be derailed from the rear sprocket.

As for lubrication and noise you also need to lubricate the bucking bar and the ball bearing that goes in the hole before it. Those parts are located in the center of the engine drive sprocket. The bucking bar is a steel pin about 8mm in diameter and the ball bearing of the same diameter.

Good luck. Let us know if the suggestions help. And your English is just fine.

Tom

KCvale · Mar 8, 2016

Daquino said:
I'll cut out the area where is rubbing, but you don't believe that can be a problem in the gears on the right ? Little lubrication perhaps?

Thank you!

As mentioned above some light lube is good but nothing on the right is going to cause your left chain to hit the front of the left gear cover and wear it like that.

Binding up on that left gear is common with a loose chain but does not cause the cover wear, I have seen that cover issue a few times and that cutting method is the fix.

The cool thing is it doesn't even show or matter as the magneto cover next to it hides it ;-}

2door · Mar 8, 2016

Read this tutorial and tighten the chain.
http://motorbicycling.com/showthread.php?p=465011#post465011

Tom

Motakitty · Mar 8, 2016

I had to shave that spot on both my motors. It did exactly what you show in your video until I shaved the cover and problem solved. Just grind that spot with a dremal or files. I suppose you could even just break the cover in that spot but I wouldn't do that.

crassius · Mar 9, 2016

I do so many per week that I now just hacksaw a line above & below, then snap off the middle with pliers.

KCvale · Mar 9, 2016

crassius said:
I do so many per week that I now just hacksaw a line above & below, then snap off the middle with pliers.

Heck, I just put the cover up against my 'fat wheel' grinder, takes less that minute.

Anyway, this is a known problem with fatter chains being used on the Skyhawk engines back when they ran #410 single speed drive chains (which I really thought worked best) to #415, but easy to correct.

To me, that fatter chain is like using a Ship anchor chain to anchor a dingy, way more chain than needed to handle the job.
Heck, HD #410 works for everything and the only reason for #415 is to try to compensate for poor rear sprocket installation or alignment.

What really cracks me up is the calls for replacement for #415 chain!
For crying out loud, if you are breaking 415 chain you have serious drive alignment issues and a new chain won't fix that, it will just continue to make the problem worse.

crassius · Mar 9, 2016

yeah, I'm stone wheels here & no time to redress after each aluminum use : (

Daquino · Mar 24, 2016

Hello everyone , sorry for taking so long , was waiting for my dremel tool . As you can see in the picture I scraped the spot.

In two or three times the sound of scratching and the stuck problem reoccurred , but giving a few more laps in two days they stopped ! However after 25 minutes with the bike without problem and forcing the engine next to the limit (just for testing , the engine has not been softened ) by turning off the bike and pushing it by hand I felt that it was locked , but nothing like the video I posted, it was enough to push twice lightly to the new stuck problem disappear .

It is possible that the expansion of the motor can be causing this since I walked for almost 30 minutes without stopping?

I'll just take another question :

The carburetor was falling from the engine with the vibration , I used tape for sealing pipes and solved the problem, however the tape is " melting " , what is the correct type of tape should I use?

Thank you!

crassius · Mar 24, 2016

nothing should be needed there - there are several diff carbs and diff intakes - one should use the kind of intake that that kind of carb fits onto tightly

Daquino · May 23, 2016

crassius said:
nothing should be needed there - there are several diff carbs and diff intakes - one should use the kind of intake that that kind of carb fits onto tightly

2door said:
Read this tutorial and tighten the chain.
http://motorbicycling.com/showthread.php?p=465011#post465011

Tom

Sorry for missing , I solved my problem sanding the cover and used another tape in the carburator, solving this to. After this I had to travel to work, but now there is a new problem.

The sound of scratching when pushing back the bike has not disappeared, I checked the entire area around and hasn't any scratch. Recently the sound of something scraping inside the engine when I 'm riding appeared to.

The clutch is actuated then it isn't the right gear shaving or the crankshaft, here is a video.

https://www.youtube.com/watch?v=psxOIb6mndc

Lubed the drive chain , lined the chain tensioner as lubed the gears of the clutch but nothing worked .

The bike rode in total 12 miles after my first topic here (03-07) and when I recorded this video was running without the gasket clutch cover since it broke when I opened the cap carefully , appeared to already be damaged.

2door · May 23, 2016

What I hear is normal chain and sprocket noise. Even with the clutch disengaged the chain and sprocket still rotate and will make some noise. I wouldn't be concerned with what I heard in your video.

Tom

crassius · May 23, 2016

I'd get the back wheel in the air, open both side covers, pull out the spark plug and listen everywhere while turning the rear wheel.

Daquino · May 23, 2016

2door said:
What I hear is normal chain and sprocket noise. Even with the clutch disengaged the chain and sprocket still rotate and will make some noise. I wouldn't be concerned with what I heard in your video.

Tom

I will monitor this sound to see if it gets worse.

And the sound of scratching when I push the bike back?

https://www.youtube.com/watch?v=cM0LveeyCUA

Daquino · May 30, 2016

2door said:
What I hear is normal chain and sprocket noise. Even with the clutch disengaged the chain and sprocket still rotate and will make some noise. I wouldn't be concerned with what I heard in your video.

Tom

crassius said:
I'd get the back wheel in the air, open both side covers, pull out the spark plug and listen everywhere while turning the rear wheel.

I solved my problem, was the lack of alignment between the crown and the pinion of the transmission.

Now i have the last two issues.

1. I have a rack gas tank, you can realize that I don't have the same amount of fuel in the filter as a tank positioned on top of the engine. This is generating a lack of fuel in the engine when I need more speed. I increased the length of the hose , but without success.

2. Is leaking fuel by the tank lid even closing well , I could not think of anything else if do not change the rubber that is on the cover , is there any other suggestions for this?

2door · May 30, 2016

These are gravity flow fuel systems. As long as the outlet of the fuel tank is above the inlet of the carburetor fuel will flow the same as with the tank mounted above the engine.
If you're experiencing a lack of fuel flow I'd look at the in-tank fuel filter or the petcock

If you see a full flow of fuel with the fuel line disconnected from the carburetor and not dripping, then fuel flow isn't your problem. It just needs to be a steady stream of any size which will be sufficient for your engine.

Fuel leaking from the fuel tank cap is common. I've had good luck with a thicker gasket made of a gasoline compatible material. Don't use old inner tube rubber. It will not stand up to gasoline. Neoprene or Viton is best.

Tom

ZipTie · Jun 1, 2016

Like 2 door said... or a big Viton O ring from a hardware store added under the cap. You may have to grind it thinner though. For your loose carb replace the junk carb bolt with a good quality Allen head and nut (add some locktite blue) so you can crank it tighter.
Where did you get the neat rack tank?

Daquino · Jul 7, 2016

2door said:
What I hear is normal chain and sprocket noise. Even with the clutch disengaged the chain and sprocket still rotate and will make some noise. I wouldn't be concerned with what I heard in your video.

Tom

crassius said:
I'd get the back wheel in the air, open both side covers, pull out the spark plug and listen everywhere while turning the rear wheel.

Hello , after another 30 days I found my problem , crassius was right, I had to put the bike with the wheels up.

Here 's what's happening, follow the video .

https://www.youtube.com/watch?v=qeaFSMlScoo

I'm turning the side of the drive chain by the side of the clutch, you can note several times that the trasmission is stuck. I believe that the problem is at some bearing.

What I need is a video or forum tutorial teaching step by step in assembling the engine with changing bearings for example. I know there are little tips on how to put the bearing in place , but I found no assembling video, only disassembling the engine. I searched the forum and found nothing , if anyone can help me I would be grateful .

ZipTie said:
Like 2 door said... or a big Viton O ring from a hardware store added under the cap. You may have to grind it thinner though. For your loose carb replace the junk carb bolt with a good quality Allen head and nut (add some locktite blue) so you can crank it tighter.
Where did you get the neat rack tank?

The problem with the fuel was solved , it was enough change the length of the hose.
I found this tank here in the forum, but I noticed that out there in the US was difficult to find it. Luckily researching I just found an online store here in Brazil selling the last two units.

Chain been stuck on the engine

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