Chain rubbing cover

[MadModder]

I ran into the sam problem on mine, I used a cutting head on my dremel and cut that area out. It worked like a charm. My other issues on my first build haven't all been so easy to remedy. But I'm getting there.

Unfortunately it seems, though considering my entire PK80 kit was under $80, I guess I can't be too mad at needing to file some things here and there, I just wish I knew precisely what I had to modify rather than keep running into little hurdes. Did you notice if the chain was rubbing on the engine as well, specifically the part that's rounded and has the threaded hole where the longest screw goes to hold on the cover? I noticed some metal is missing there too so I put some blue paint over it to see if the chain grinds it off so I know I need to file that down too. I'm sorry to hear about all the problems you're experiencing though, trust me, I understand! Though most of my problems are honestly probably due to my choice in bike, not my kit. Most everyone here seems very helpful and willing to share their knowledge so hopefully you'll be able to get everything ironed out and get your bike going!

 

[crassius]

sounds like chain too loose unless motor is tilted way up in front

 

[MadModder]

sounds like chain too loose unless motor is tilted way up in front

Idunno, this time around I had a buddy help me push on the tensioner while I fully tightened it down, and used thread locker on the bolts and so far it's held up a lot better with the new bolts than it did last time around. Even managed to get and keep the engine running without breaking the chain today
I found the one noise Im hearing is actually coming from the clutch side, I guess it's just slight tolerances between the two gears so at slow speeds it makes a knocking sound as tooth from the larger gear makes contact with the smaller gear.
At this point my main issue is just the idle. It's so sporadic and and all over the place that trying to adjust it while the engine is running is very difficult and seems futile. The last time it ran it was at times incredibly close to stalling, then would randomly rev up act as if it was wide open, shooting the RPMs would through the roof and it would shake violently with barely no change to absolutely no change in the idle screw at all. I thought maybe it was the needle setting so I bumped the c clip up one notch but couldn't get it to start at all then. While it was running I loosened the adjustments I made to the throttle cable at both ends in case it wasn't just picking up the slack between the cable and cable housing and was actually pulling in the throttle, as well as essentially moved the screw from completely out, to completely in while simultaneously pulling up the slack on the cable at the throttle, but still no luck. I mean I'm glad I've even got it to start at this point, but in the short minute to two minutes the engine was on both times it got extremely hot(and it was around 45°F tops). I did have to cut the intake manifold to fit on the carb until I receive my offset one, but based on the wide variances of manifold lengths available I can't imagine removing 10mm would cause all this, would it?

 

[MadModder]

Scratch that, pretty much certain there's a leak in the joint between my carb and intake, put a few layers of ptfe on and hoping that'll balance out the idle in the morning

 

[steamburn]

Same problem with the gear cover. I dremeled it down with the cutting wheel. The chain clears it now without a problem.
But another problem popped up.....the chain was getting out of the rear gear because some of the teeth had protrusions. I filed a little bit each rough tooth in a manner as if I was sharpening them and now the chain slides perfectly.
Another thing I did was to install a spring tensioner like the ones Turbobuick sells in eBay. That is a fantastic improvement over the dangerous tensioner that comes with the kit. Ralph Nader would have ha a heart attack if he would have seen it.

 

[Frankenstein]

Check your engine mounts, if they are too loose and the carb vibrates too much it does the weird throttle thing, basically there's something kc invented called the shove test, grab frame with one hand and engine head with the other, push and pull as hard as possible on the motor, if it moves its a fail.

If that passes maybe take the look inside the carburetor again, specifically the bowl, if you have crap floating around in there it clogs the jet and makes adjusting things next to impossible as silt clogs and unclogs from the jet orifice.

 

[MadModder]

Another thing I did was to install a spring tensioner like the ones Turbobuick sells in eBay. That is a fantastic improvement over the dangerous tensioner that comes with the kit. Ralph Nader would have ha a heart attack if he would have seen it.

I was wondering about them myself. I saw some guy on YouTube had one that mounted to(or maybe was a direct replacement for) the drive sprocket cover to tension the chain right at the drive gear which seems like exactly what I need since my chain stay and seat stay have weird bends in them that put ls the chain tensioner at a slight angle unless it's very close to the seat tube. I just can't believe how expensive some of them are.

Check your engine mounts, if they are too loose and the carb vibrates too much it does the weird throttle thing, basically there's something kc invented called the shove test, grab frame with one hand and engine head with the other, push and pull as hard as possible on the motor, if it moves its a fail.

If that passes maybe take the look inside the carburetor again, specifically the bowl, if you have crap floating around in there it clogs the jet and makes adjusting things next to impossible as silt clogs and unclogs from the jet orifice.

Lol, well last night while trying to fit my carb back on I tried moving the engine thinking it would move a little but it seems my bottom mount v2 is working much much better than the first one and passed the test. After another entire day I trying to get it started I finally decided it couldn't hurt to bump the c clip up another notch to the middle(since my spark plug was basically black from that short time I had it running before), and go rigifi this time the first go it started. Couldn't keep it running, but at least it's starting now at a leaner setting than before. And while it did start revving up pretty hard for a short while while I was adjusting the idle screw, and ultimately stalled all three times I got it started, it seemed much less crazy than before, and seems much much closer to starting everytime now. I definitely still have air leak where the carb meets the intake so hopehopef that offset one comes soon and will sort most of this out.
On a side note, has anyone ever used #41 chain(also called 410) rather than 415? As mentioned earlier, even after replacing the first broken link with one I had removed the chain has broken two or three times within 3 links to the left I right of the original break so I definitely think replacing it is necessary at this point if I ever want to go farther than the driveway, and someone on YouTube mentioned 410 chains, which I've found for like $21 for 10ft, which is around what the Chinese 415 replacement from AliExpress costs, yet that would give me basically an entire extra chain, and they seem to be slightly more robust than the 415 chains. The 415 is about $26 for 10' which isn't bad compared to the price of a single chain, but if I can use a slightly thicker chain I'd prefer that.

 

[crassius]

41 is a bit wider, but works OK if it clears your fender and frame

 

[FurryOnTheInside]

#410 is bmx/track bike chain and it's what I'm using at the moment. You have to make the drive sprocket 1/16" narrower to fit it.. but you get to choose which side of the sprocket to grind away so it can help you get the alignment perfect. You can improve the tooth profile slightly while you are doing that.

#41 is for a garage door opener, I believe. I'm not building a garage door opener so I haven't tried it. Lol.

 

[MadModder]

Ah yep, got confused by one of the questions on the page for the chain, they are indeed different. Once again now I'm torn between two parts. On one hand the larger chain is probably more robust and would maybe even offer a little wiggle room in small variances in the rear sprockets side to side movements if there is still any, but if I had problems with the 415 chain then maybe a thicker one will just not work at all or require a lot more material to be removed, where a thinner chain as mentioned will require sprocket modifications or a thinner sprocket, but may get rid of all the noises I'm hearing from the drive sprocket but may also be less robust than the existing chain -_-