70cc lost of power (help!!!)

arielatom300heps

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Can some one tell me what's wrong with my 70cc engine?

Yesterday when riding to a mate's house I had it maxed out at about 55km/h when it suddenly reduced to about half power even those I had throttle at full power. I got off the gas and tried to accelerate up to speed again but it had no power. It would only get to about 30km/h and it took a long time to get there.

When I arrived at my mate's house we took carbie apart and cleaned it out along with the fuel line with air compressor. Power came back a bit but it is only running at about 70% of what it used to and maxes out at around 40km/h.

Can someone give me advice on what it could be?

Mark
 
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stude13

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hi mark; sorry to say but i think you engine is fried. i believe it leaned out and burned the piston, ring and barrel. you will have to open it up to see. good luck mitch
 

datz510

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Yep, pull the head off and see what the cylinder looks like.

These engines dont live long running full bore. I've got mine geared to cruise at about 1/2 to 2/3 throttle to maximize the life of the engine.
 
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hi mark; sorry to say but i think you engine is fried. i believe it leaned out and burned the piston, ring and barrel. you will have to open it up to see. good luck mitch

Stud may be correct.

Also when Running lean And high revs for a period will Heat up your Lower rod Bearing Eventually seizing them.

A dirty carburetor or Incorrect fuel delivery could give same Symptoms.
A bad Ignition would give you A switch being turned on and off feeling.
A bad Plug will give you the same effect but usually a plug works or it don't.

I hope its nothing Major

First thing to do is Check the Plug.
If read correctly it will tell you a good story And you can usually rule out a few factors.
Next check compression.

If all is good try new fuel

I hope its nothing serious .

good luck

Cheers

Bob:)


BlueCollarBike
 
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arielatom300heps

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Thanks for all the helpful info & tips everyone.

I will take the engine apart some time this week and see if I have fried any thing.
Do u think it could have been because I was running it 98 octane unleaded petrol and not on 91 octane unleaded petrol

I think I might have done some minor damage to engine but I would have thought if it was running lean and over heating then the power would have slowly gone away not suddenly like I experienced.
 

datz510

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The octane wouldnt do anything bad to the engine. THe real question is whether the engine was being run all out full throttle for hours on end. That's what destroys these motors.
 

arielatom300heps

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I think i might have found the problem.

I took the carby apart completely and got some dirt out of it and now its running better.

I checked spark plug and it was a browny/black colour and so i have read this means it was not running lean and that the problem must have been the dirt in the carby.
 
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I think i might have found the problem.

I took the carby apart completely and got some dirt out of it and now its running better.

I checked spark plug and it was a browny/black colour and so i have read this means it was not running lean and that the problem must have been the dirt in the carby.

Great news.:D

Cheers

Bob

BlueCollarBike
 

Jakylpops

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I've been having the exact same problem the last couple days, so I finally took my carb apart. The whole thing was nice and clean inside, not a speck of dirt anywhere...BUT...

...my float was half full of gasoline:mad::mad::mad:

It had a tiny little hairline crack in the wall of the "donut hole". The crack was so small I couldn't even get the fuel back out, so I had to drill a little hole, drain the float, clean it up really good, then patch the holes with JB weld...still waiting for it to cure right now.
 
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