Chain sticking/clicking/grinding...Need help!!

[fadam00]

Hi everyone,

Pretty new to all things motorized bicycle. I've got a 2-stroke 80cc road motorbike in its engine-breaking period. All was working fine until the chain started jumping off/skipping. I had tried adjusting the tensioner as per a few videos on youtube that I found, and that didn't do it.

I then decided to cut the chain a bit shorter thinking it was too much slack, and cut it a little too short and the chain currently has about 4 master links (read somewhere that it doesn't matter how many master links you have, please correct me if that's incorrect). Tried riding it and it worked for a couple of blocks then it started getting stuck...

From what I've read in different posts and learned from other videos it could be an issue with the motor alignment (making sure the chain is straight from the motor drive-train to the rear sprocket), the rear sprocket alignment (which I re-installed also to try and fix the problem and made sure there is no wobble), or I need a new chain..

Not exactly sure what's going on or what to do, and definitely need some help. I've attached some pictures and a video in hopes that it can provide clarity on what's going on!

Video:

Images:

 

[allen standley]

Welcome Fad!
Engine cocked crooked in frame is my first guess. Great you posted pics but they are puzzle pieces to me. I gotta lay down to understand them. Looks to be a drastic forward tilt to the engine. You may have to remove the engine from frame and consider a different forward mount to reduce that. https://www.amazon.com/dolphin1986-...qid=1583315219&sourceid=Mozilla-search&sr=8-4
. Using the rubber rag mount allows for ZERO lateral rear sprocket adjustment. Multi speed rear wheels can be a bit hit or miss. Flipping the rear sprocket so it dishes the other way may be a better alignment? Pull the clutch arm cover 3 bolts and look for WEAR areas.
Best upgrade for the drive line is one of these. Measure the diam of your rear hub and look forward to purchasing one of these in the near future.
https://www.amazon.com/CDHPOWER-Rea...5728&sprefix=gas+bike+sprocket,aps,146&sr=8-6

 

[Greg58]

I'm with Allen, can't tell much from the angled pictures. We can't see the front mount of the engine but it has to be mounted solid to the frame without a gap and do not use rubber between the mount and frame. I make my front mounts to fit each bike because most are slightly different. I forgot, welcome to the forum.

 

[fadam00]

Thank you for the responses and the welcome! I can take some more pictures, that's not a problem. What angle/component of the bike would be helpful for you to see?

Also, I raised the motor that way to create some clearance for the pedals. If I mount it lower so the motor can be mounted using BOTH mounts the pedals hit the exhaust/muffler which is another frustration.

Would the bike run okay if it's mounted with the rear mount only as it is now and I get a rear hub adapter like the one Allen posted? Or does the motor HAVE to be mounted solidly on both ends?

Again thanks for the prompt replies and helpful info. Looking forward to hearing back from yall!

 

[allen standley]

Would the bike run okay if it's mounted with the rear mount only
NO! Most important gotta be solid @ both points.
If your pedal clearence is an issue and minor enough you can take a body grinder to the back side of the pedal crank to allow clearance, if not, we got another prob.

 

[fadam00]

Allen, thanks for the straightforward answer!

So first hings first, I gotta bolt the engine on both mounts. I'll grab the items you suggested above for that.

Afterwards would there be any other suggestions, or do you believe that may most likely fix the alignment issue? As you had mentioned there's an excessive forward tilt.

Also two more things..

1) Is the whole using multiple master links on the chain an issue?

2) If I mount the engine properly, the metal arm of the pedal crank will hit the muffler/exhaust. Have this happened to you previously? Any suggestions on what to do/buy?

Thanks again for the help, and I'll be posting more pictures tonight providing different angles of the setup.

 

[allen standley]

Glad to be of some help Fad. It's all a process of tackling issues one at a time. Knowing which prob to tend first is most important.
1) Is the whole using multiple master links on the chain an issue?
well - You should not need more than one master link, more than one is one more than needed, with that said there are half links avail also. You Should own a chain breaker like thishttps://www.amazon.com/AZSSMUK-Detacher-Breaker-Motorcycle-Replacement/dp/B079K9YPJL/ref=sr_1_10?keywords=motorcycle+chain+break&link_code=qs&qid=1583331685&sourceid=Mozilla-search&sr=8-10
Tractor supply carries #41 machine chain which works nicely with our bikes. It is slightly more narrow than the 415H that comes with the kits. Box contains enough chain to complete 2 bikes (10ft) with several links left over. Before throwing more money @ the prob. Pull that cover and look at the wear marks which will give you better insight to the grinding prob. Look at the Master Links to see if any Alum "skin" is in them. I do think more than one Master link can contribute to chain travel issues especially in the clutch cover and around the small drive sprocket. Inspect the cover and chain @ master links but don't fix this yet... Let's do a couple other things first.
2) If I mount the engine properly, the metal arm of the pedal crank will hit the muffler/exhaust. Have this happened to you previously? Any suggestions on what to do/buy?
Yes, another common issue. So set me straight-- here. Can't lessen engine angle due to muffler clearance issue and pedal crank issue.
Accept the fact you can not ride for a couple days here till the two issues above are tended.
Remove the muffler from the engine, Remove the Chain from the engine. The only thing now preventing a good solid install is that Pedal crank. Start with this. Now -- If you can grind away enough metal from the back side of the pedal crank to clear the motor. that is one problem solved. The immediate objective is to mount the engine in the "V" as low and snug as possible to insure the best mount. So I f grinding is not an option you may need to purchase a wide crank set found here. https://www.amazon.com/CDHPOWER-Con...ds=wide+pedal+crank+kit&qid=1583331065&sr=8-5
This alone could solve both clearance issues. Do some measuring and looking for the correct kit for your particular bike. Local bike shop comes to mind.
The muffler can be dented or bent using heat from a propane torch and a bench vise. Mount that motor in the frame first. It is possible drive line issues will disappear after mounted well?? Keep us posted.
See my Album "Happy Chains" for some drive line tips.
https://motorbicycling.com/media/albums/happy-chains.1499/

 

[Greg58]

I have had to oval the muffler mounting flange holes to swivel the muffler out of the way of the pedal, then use removable thread locker on the studs. Use thread locker on everything!

 

[fadam00]

Gents,

Thank you again for the help, and Allen for being so detailed!

As promised, you'll find another set of pictures that will hopefully provide better angles and more clarity. If anything it'll confirm your suggestions.

I've also gone ahead and ordered the forward mount to mount the engine properly. I'll deal with the pedals once I install the mounts properly and keep y'all posted.

 

[allen standley]

Excellent Fadam! You are on the right path. I shall follow you along.

 

[fadam00]

Hey Allen and others!

Quick update... I've installed the engine correctly (I believe lol, would love to get a check on it). Now, as we had suspected the pedal hits the muffler.

I've attached a video of the pedals hitting the muffler, and pictures of the engine install.

Video:

One more set of pictures you'll find are of the pedal/crankset... I've also take pictures of another bike I have and I'm wondering 1) would any of you know where to grab a wide crankset of the same kind or that it's compatible with the road bike? 2) would the crankset of the other bike fit the road bike (the one with the engine), or would it be worth trying to replace the crank arm on the road bike with the black on shown which has a bend and hence is wider?

Thank you so much for your continued help and support!!

 

[fadam00]

Hey Allen and others!

Quick update... I've installed the engine correctly (I believe lol, would love to get a check on it). Now, as we had suspected the pedal hits the muffler.

I've attached a video of the pedals hitting the muffler, and pictures of the engine install.

One more set of pictures you'll find are of the pedal/crankset... I've also take pictures of another bike I have and I'm wondering 1) would any of you know where to grab a wide crankset of the same kind or that it's compatible with the road bike? 2) would the crankset of the other bike fit the road bike (the one with the engine), or would it be worth trying to replace the crank arm on the road bike with the black on shown which has a bend and hence is wider?

Thank you so much for your continued help and support!!

 

[Greg58]

Here you go.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/192743317556

 

[allen standley]

Engine install looks good! Before throwing money in a new crankset I would remove the muffler from the engine and place it in a bench vice, apply some heat with a propane torch and bend the muffler tube inward. A small bend in the right place is all you need to make this work.
If you decide to throw any money at it I would do a different exhaust altogether. Like this one
https://www.amazon.com/dp/B01N5T44RW/ref=twister_B07CP5FY7T?_encoding=UTF8&psc=1
Exits up and over the top of the engine, Gotta warn you it is loud. Other options are avail.

 

[Greg58]

It doesn’t need much, like I’ve posted before you can in-large the muffler mounting holes just a bit and it will clear.

 

[fadam00]

Hey gents,

I was successful in slight bending the exhaust inward to clear the pedals!! I also bought #41 chains to change the stock one as suggested in a previous response and now it isn't catching at all and turning great.

But as it's with life if it isn't one thing it's the other... Although the chain works well and the engine turns on, it has significantly lost power. To the point it shuts off even with rhw choke lever all the way up.

A few thing to know:

1) The bikes been sitting for over a week. The only use it's gotten has been when trying to turn on for like 10 seconds about 4 days ago when attempting to fix previously.

2) For fuel, I'm using the suggested 16:1 gas to oil ratio for break-in. I'm using synthetic oil in the mix.

The bike turns on, and the engine turns over.. However, the sputter is weak and I feel it losing power even with choke all the way up and full throttle. It's not an abrupt shutdown, but more gradual.

Any of you could provide some of your sage advice or point me to a previous post that may contain the answer?

Thank you both so much for taking me where I'm at right now. All in all, just being able to get past the chain issue which I had been dealing with for easily 2+ weeks is an awesome relief and it felt liberating to feel the breeze... for at least 5seconds before the bike shut down .

 

[Greg58]

Good you got everything mounted correctly, 16/1 is one problem, 24/1 is more than enough oil. I would change fuel mix then clean or replace the spark plug. Once you get it started let it warm up a bit before you turn up the rpm's, a carburetor engine has to warm up to run correctly.

 

[allen standley]

If it were me... I would drain the tank of remaining fuel and empty the 16:1mix into my trucks gas tank and forget about it.
Start fresh with a 32:1 (4oz oil/1gal gasoline) mix. I think it important for you to peruse through these threads for some insight. https://motorbicycling.com/search/33111150/?q=carb+float+adj&o=date&c[title_only]=1
The carburator shown in your pic is a standard kit NT. The simplest, and in my opinion easiest to work with. When set up right - my opinion - provide very good performance. Could be the float fork needs a little tweak. Without knowing for sure I guess to say "the float may be allowing too much fuel into the bowl". You mention above However, the sputter is weak and I feel it losing power even with choke all the way up and full throttle Does the choke up help to keep it running?
Do you live and ride in High country or low lands? Geography wise, what is your elevation sea level?

 

[fadam00]

Hi Greg and Allen,

It works!!

Here's what I did:

1. Started with a fresh tank of 32:1 (93 octane + synthetic 2 stroke engine oil).
2. Turned the idle screw "in" to allow for more idle
3. Allowed the engine to warm up for 30secs-1min (I pedaled the bike with clutch engaged)
4. Once the engine was warmed up, I eased into the throttle and let the baby run alternating between a bit of throttle and full throttle gradually. After about 5mins, I was able to run it normally....of course, with the chain behaving as it should

One more thing I learned...the choke must've been installed wrong as when I pushed the lever up (toward the seat of the bike) the engine start sputtering, and when I push it down it revs faster.

Upon learning this I simply opened the choke about 75% and it worked fine from there.

Want to thank you both again for helping me through this! Couldn't have done it without ya'll.

Oh! Forgot to also add the video I used to bend the muffler, maybe others in the forum will find it helpful if they stumble upon this post:

It worked great for me.

Also, given I'm still a newbie and the engine is on its breaking period, if you have any guide/thread/video that has been posted previously or you know about on how to break-in the engine properly I'd super appreciate it.

Lastly, I look forward to helping other in the forum with the problems I just had.

Thanks again!

 

[Greg58]

I do several short runs to put the engine through heat cycles, let it cool completely between rides. FYI 32/1 is what I’ve run in my bikes (actually everything 2stroke) for decades.