Engine Trouble Horrid Grinding Noise When Going Above 18mph

[CrispyLeaves98]

Hello!
This is my first motorized bike, I've been having nonstop fun with it. I will include a video later, but the problem is when I go 18mph or above or If I have the clutch pulled in and go like 4/6ths throttle it makes a horrid Grinding Noise, making it so I don't go that fast. The noise goes away if I pull in the clutch and let go of the throttle. I know the normal slight grinding sounds when you ride and I promise this is different. I am trying to find a solution, anything helps.

 

[CrispyLeaves98]

Probably the gear coming off and grinding against the case.

What would be a solution to that?

 

[Karl Snarl]

What would be a solution to that?

Use a shcs instead of the supplied flat head screw. An a little smurf blood ( blue locktite).

 

[CrispyLeaves98]

Thank you!

 

[Karl Snarl]

Np, ive had the same problem before. Hope it helps ya enjoy your ride.

 

[LewieBike]

Use a shcs instead of the supplied flat head screw. An a little smurf blood ( blue locktite).

Yeah the slot head bolt is also locktighted in with some fairly resistant to loosening threadlocker. Giving that bolt a once over with a MAPP torch helps it break loose. Be careful to not spend too much time on the bolt with the torch, just enough to get it smoking a little. You don't want to damage the right side engine seal with too much heat conducted down the right crank main shaft.

Note that a replacement bolt easily found in bike shops is the fine pitched 8 mm sized hex head, bolt used to hold good quality 3 piece alloy cranksets onto their tapered spindles. It's also made of better quality steel, the metal in the HT engine pinion gear bolt is like cast iron.

 

[Karl Snarl]

Yeah the slot head bolt is also locktighted in with some fairly resistant to loosening threadlocker. Giving that bolt a once over with a MAPP torch helps it break loose. Be careful to not spend too much time on the bolt with the torch, just enough to get it smoking a little. You don't want to damage the right side engine seal with too much heat conducted down the right crank main shaft.

Note that a replacement bolt easily found in bike shops is the fine pitched 8 mm sized hex head, bolt used to hold good quality 3 piece alloy cranksets onto their tapered spindles. It's also made of better quality steel, the metal in the HT engine pinion gear bolt is like cast iron.

Excellent advice about the torch. Most will not know there is a rubber seal back there the first time playing with these engines. Good call.

 

[CrispyLeaves98]

Uh oh. I took off the cover on both sides of the engine, but on the side that has 2 parts, I took that one off too. I did grease up the right side, but now my bike won't engage. Pulling in the clutch still makes it easier to pedal, and I can assure you it's not a cable tightening issue. Now my engine won't engage. It will a bit more if I let go of the clutch, it sounds as If the engine may turn but it doesn't. It's not a cable issue. What else could it be?

 

[CrispyLeaves98]

Excellent advice about the torch. Most will not know there is a rubber seal back there the first time playing with these engines. Good call.

Sadly, I don't have a torch. But now I am having other issues

 

[Chainlube]

Uh oh. I took off the cover on both sides of the engine, but on the side that has 2 parts, I took that one off too. I did grease up the right side, but now my bike won't engage. Pulling in the clutch still makes it easier to pedal, and I can assure you it's not a cable tightening issue. Now my engine won't engage. It will a bit more if I let go of the clutch, it sounds as If the engine may turn but it doesn't. It's not a cable issue. What else could it be?

On the right side there is a tear shaped cover, take it off, pull back on the clutch arm in your picture and turn the flower nut in the center of the plate. But first remove the retaining screw, and put it back once you turn the flower nut in a bit.

 

[CrispyLeaves98]

On the right side there is a tear shaped cover, take it off, pull back on the clutch arm in your picture and turn the flower nut in the center of the plate. But first remove the retaining screw, and put it back once you turn the flower nut in a bit.

chains lubed!!! Ill give this a shot whenever i get back! Thank you so much for the help! I will upload pictures. if this does not work, any other ideas??