losing power

shafertimothy

New Member
Nov 25, 2008
8
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0
florida
I have a raw engine which was running fine at 30 + mph but over the past week it tops out at about 23-25 mph it also is not reaching as high of rpm's I noticed some oil around the air filter please help
 

mechanickid

New Member
Aug 7, 2008
419
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nh
i would check my gaskets if you haven't already replaced them. and the oil around the air filter may be leaked gas that collected dirt, it was for me anyway. are you running the right mix? oil tends to settle after a long time and it may have gone down your tube, it may be a while b4 it runs out but it wont hurt the engine.
 

jasonh

New Member
Jun 23, 2008
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Longmont, CO
Also check the color of your plug and make sure it's not oily or too dark. Should look like milk chocolate. you could be running too rich.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Sounds like the carb either spit a little fuel into the filter (normal) or it just got cruddy like they do. Clean the foam in dishwashing liquid and let it dry after you rinse and sqeeze it out.
 

shafertimothy

New Member
Nov 25, 2008
8
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0
florida
:crash::crash::crash:ya i checked the plug its fine. oil mix is right on. i did take the exaust of and gained dramatic power. enen tried ajusting the cab didnt work is this a comman problem with the engines?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
Take the guts out and make sure the outlet hole is open. I ground off an outlet (I was making an extension) and found that the outlet hole was almost welded closed!

See the photo- that hole is smaller than the small through bolt.

After you open up the exhaust, keep an eye on your plug, and test ride and re-tune the carb.
 

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shafertimothy

New Member
Nov 25, 2008
8
0
0
florida
well i ahve tried everything but i still am wondering if it aint the exuast my muffler doesnt have a removeable baffle it is on solid piece what can i do to it to help
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
If you are losing power, I doubt if the pipe just plugged up or something like that in a short time.

I'd look again at the plug (replace it with a good NGK or Autolite) and double check again for air leaks....pipes just don't "go bad".
 

Allan

New Member
Nov 23, 2008
17
0
0
Ontario, Canada
shafertimoyhy,
Has it backfired on you? If it has,as a last resort, pull the head off and look for scratches on cylinder lining. If your losing power you maybe losing compression. Where you riding on wet roads? If you where, pull the head off and look for damage.
Regards,
Al
 

shafertimothy

New Member
Nov 25, 2008
8
0
0
florida
:crash:no i dont have a pic of the pipe. but it is a black solid pipe with a little hole at the end the whole thing is welded together from the factory. i have changed the plug. tried ajust on carb could it be the kill switch? i took the pipe off and ran it for about a block and noticed a dramatic increase in power and top end. please help.
 

Dave31

Moderator
Staff member
Mar 1, 2008
11,204
29
38
Aztlán, Arizona
I"m wondering if this is'nt another vibration problem causing the fuel to foam in the carb...have you checked to be sure you have no loose motor mounts?

Do you have a vibration at higher RPM's?

I do not think its a muffler problem but if you have a grinder you can grind the welds off the cap to open it.
 

shafertimothy

New Member
Nov 25, 2008
8
0
0
florida
No there is'nt any vibration. there used to be when it was going alot faster then it stoped and now i dont have as much power so i dont think vibration is the problem.
 

xPosTech

The Old Master Motorized Bicycle Builder
Oct 23, 2008
209
0
0
SETexas
You said you get a dramatic power increase running with no muffler. You can get a replacement from most of the suppliers. Or, do as David suggested and grind the welds off the end.

If it is totally welded up it may be a (badly) repaired muffler. It would not surprise me to find a repaired part in a kit if, say, revolution was low on parts. It is rare but not unheard of.

Why don't you try this: Remove it and (using a piece of rubber hose if you don't want black lips) blow through it from the manifold end. Any obstruction?

My muffler (chrome) is short and fat compared to the one in your pic.

The thing about plugged mufflers is the engine usually won't start if they are plugged. An old wedding reception trick is to stick a potato in the groom's tailpipe(s). No man, on the car! It won't start. Easier than trying to remember which plugs the wires went to.

Ted