Motorized Bicycle power output going on and off (Noise)

[Sharif]

So I ffed up the one I was previously extracting using the allen keys and did way too much damage and further some more stupid ideas. On the bright side from all the mistakes of the first one I extracted the other bolt cleanly.

I will be using 6 inch hose clamps to strap the engine down from the top, will update later tonight after I put everything back together.

 

[Sharif]

It's on the silly side of things the way I got it clamped, but only time will tell if it holds. if not I will add few more clamps lol

Also added a new exhaust and spring loaded chain tensioner.

I was getting power cuts on the way back from work, but it's likely the quick wiring I did to get to work on time, which I will actually solder in a little while.
I am having issues with the fuel not flowing, moment I remove the hose fuel flows right out, but not when the hose is attached again. Had to squeeze the fuel lines like a pump to get it flowing and it actually worked, was a hectic ride to work.

 

[Sharif]

I am still getting power cuts, sometimes even at much lower RPMs.
So I completely cleaned out the carb, only to not make a difference.

The only thing I can think of is sparkplug boot cap that was put on and off good few times over the weeks and stop switch.

I have been putting off from swapping the bootcap as I can't find spark plug wire by the foot, just the sets being sold. I already have a replacement NGK bootcap I bought a month ago.

Any pointers would be appreciated

 

[gary55]

I am still getting power cuts, sometimes even at much lower RPMs.
So I completely cleaned out the carb, only to not make a difference.

The only thing I can think of is sparkplug boot cap that was put on and off good few times over the weeks and stop switch.

I have been putting off from swapping the bootcap as I can't find spark plug wire by the foot, just the sets being sold. I already have a replacement NGK bootcap I bought a month ago.

Any pointers would be appreciated

If it's acting the same way it was with the broken motor mounts then the hose clamps didn't solve the issue.

 

[Sharif]

If it's acting the same way it was with the broken motor mounts then the hose clamps didn't solve the issue.

Hose clamp is surprisingly doing quite well hahaha.
I think it was an exhaust leak, saw oil dripping from the gasket area and swapped to the old exhaust, so far so good. The reason it was leaking was, because it was an extremely tight fit (thought I pulled it off) and didn't surprise me, that the exhaust wasn't able to completely seal flush against the gasket.

Will update

 

[Sharif]

Update

The issue was just the exhaust gasket, that is crumbling into pieces, tried using red RTV, but it's not really meant to be used around gasoline related areas, will see how it goes.

 

[Spare_Parts]

Dorman 47021 for exhaust gasket

• Spare_Parts
• Oct 1, 2018

Needs to be modified. The holes for the studs are 45mm center. I used a round file to move them...

Or, bicycle motor works has these. Haven't tried them yet.

Set Of 3 High Performance Motorized Bicycle Exhaust Gasket Metal Reinforced | eBay

Find many great new & used options and get the best deals for Set Of 3 High Performance Motorized Bicycle Exhaust Gasket Metal Reinforced at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Sharif]

Dorman 47021 for exhaust gasket

• Spare_Parts
• Oct 1, 2018

Needs to be modified. The holes for the studs are 45mm center. I used a round file to move them...

Or, bicycle motor works has these. Haven't tried them yet.

Set Of 3 High Performance Motorized Bicycle Exhaust Gasket Metal Reinforced | eBay

Find many great new & used options and get the best deals for Set Of 3 High Performance Motorized Bicycle Exhaust Gasket Metal Reinforced at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I just purchased the exact same thing today from Napa Auto lol

Did a test run after that and everything seems fine now

 

[Sharif]

Seems like everything is mostly fine, don't have exhaust leak anymore but still have that issue happen moment I go over 35 km/h.
I got it to happen less often when I went down to 1:20 mix from 1:24.

Last night I managed to get to 42 km/h after a good while, I was just going on and off the throttle and it actually worked.
Pretty certain hose clamp is holding the engine pretty well and I have carb tied down to the frame as well.

 

[Sharif]

I have been doing some thinking, this sticking to 35kmph max is getting silly, it might be the float I adjusted while cleaning the carb (Unknowingly, I bent the tang downwards hoping it would be more sensitive idle quicker) that's another issue I need to figure out, why it takes so long to go down in rmp (By long I mean 10 seconds or so)

If I can find a bit of time tomorrow, will take the carb off.