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adonets · 03-25-2010, 04:51 PM

I have a Sachs MadAss 88cc bike, 50cc engine with some performance parts on it. The bike is 1 speed.

My problem: when throttling anywhere from 0-95% of the throttle's capacity, it is perfectly fine, accelerates as it should and everything works well. However, when I absolutely crank it to 100% to where the throttle cannot go any further, the engine starts to act funny, and would decelerate in 0.1 seconds and accelerate in that time again, so sort of like have a very jumpy, vibrating speed. It's not like it would decelerate over 3 seconds then accelerate again, it would do this in a fraction of a second.

Is this normal? Am I ****ed? I hear from a guy that this could be a problem with my carb.

MOKE1K · 03-25-2010, 06:17 PM

Sounds like your getting to much fuel threw to small of a main circuit or mainjet, if your needle is adjustable you may beable to accomplish the adjustment with your current mainjet, if not you'll probably have to go a size bigger on the mainjet. Good luck.

The_AirHawk · 03-25-2010, 06:18 PM

Sounds like someone is on the rev-limiter........

adonets · 03-26-2010, 08:51 AM

Quote:

Originally Posted by The_AirHawk

Sounds like someone is on the rev-limiter........

Could be. How do I get off from it?

A Star Ride · 03-26-2010, 09:04 AM

The rev limiter is designed to prevent you from over-reving the motor. When the RPM's exceed the target range for that gear, the limiter kicks in to prevent you from going beyond that point & potentially causing engine damage.
Try leaving the bike in a lower gear (anything other then top gear) and keep accelerating, you'll notice the power dies off and the engine seems to "miss". If thats the same symptom your getting at higher speed in high gear, the limiter is preventing you from accelerating beyond that point. You can also just open the throttle in neutral & the limiter will prevent you from overreving it, the sound will be there but you won't experience the power loss.

A Star Ride · 03-26-2010, 09:07 AM

You said single speed engine, sorry. Your probably already at the top speed the bike is designed to go. You can disable the limiter, but your asking for trouble if you do.

Kenneth_Moore · 03-26-2010, 09:55 AM

An 88cc bike with a 50cc engine.

Maybe you should get a bigger bike.

mscuddy · 03-26-2010, 10:03 AM

Is it a two or four stroke? If it's a two stroke, and you have performance parts on it (chamber, ported cylinder, etc) you will have to either raise the needle in the slide to get more fuel in the motor at full throttle, or get a bigger main jet.

If it's a four stroke, throw it away.

adonets · 03-26-2010, 03:12 PM

Quote:

Originally Posted by Kenneth_Moore

An 88cc bike with a 50cc engine.

Maybe you should get a bigger bike.

First, learn to read.
Second, learn to use your head; your comment makes no sense.
Third, and lastly, you did not answer or even touch on answering the topic designated to the thread. Go to 4chan if you want to keep being an idiot.

adonets · 03-26-2010, 03:16 PM

Quote:

Originally Posted by mscuddy

Is it a two or four stroke? If it's a two stroke, and you have performance parts on it (chamber, ported cylinder, etc) you will have to either raise the needle in the slide to get more fuel in the motor at full throttle, or get a bigger main jet.

If it's a four stroke, throw it away.

It is a four stroke. It is new. Why am I throwing it away? Please elaborate on your suggestion.

03-25-2010, 04:51 PM	#1
adonets Registered Member Join Date: Mar 2010 Posts: 20	Full throttle problem I have a Sachs MadAss 88cc bike, 50cc engine with some performance parts on it. The bike is 1 speed. My problem: when throttling anywhere from 0-95% of the throttle's capacity, it is perfectly fine, accelerates as it should and everything works well. However, when I absolutely crank it to 100% to where the throttle cannot go any further, the engine starts to act funny, and would decelerate in 0.1 seconds and accelerate in that time again, so sort of like have a very jumpy, vibrating speed. It's not like it would decelerate over 3 seconds then accelerate again, it would do this in a fraction of a second. Is this normal? Am I ****ed? I hear from a guy that this could be a problem with my carb.

03-25-2010, 06:17 PM	#2
MOKE1K Registered Member Join Date: Jul 2008 Location: Kalapana, Big Island Posts: 3,956	Sounds like your getting to much fuel threw to small of a main circuit or mainjet, if your needle is adjustable you may beable to accomplish the adjustment with your current mainjet, if not you'll probably have to go a size bigger on the mainjet. Good luck. __________________ "YOU CAN'T BOLT ON SKILL" "The only thing limiting your bike, is you" We survived Bush you'll survive Obama! "the most fundamental fact about the ideas of the political left is that they do not work. therefore we should not be surprised to find the left concentrated in institutions where ideas do not have to work in order to survive." --thomas sowell

03-25-2010, 06:18 PM	#3
The_AirHawk Founding Member Join Date: Jun 2007 Location: Livin' in a Van: down by the Mariana Trench Posts: 10,891	Sounds like someone is on the rev-limiter........ __________________ *Parfois, on fait pas semblant* Sometimes, it's not pretend Oderint Dum Metuant Let them hate so long as they fear политики предпочитают безоружных крестьян Politicians Prefer Unarmed Peasants Nothing to see here, Citizen. Move along now...

03-26-2010, 09:04 AM	#5
A Star Ride Registered Member Join Date: Oct 2009 Location: central Va Posts: 1,126	The rev limiter is designed to prevent you from over-reving the motor. When the RPM's exceed the target range for that gear, the limiter kicks in to prevent you from going beyond that point & potentially causing engine damage. Try leaving the bike in a lower gear (anything other then top gear) and keep accelerating, you'll notice the power dies off and the engine seems to "miss". If thats the same symptom your getting at higher speed in high gear, the limiter is preventing you from accelerating beyond that point. You can also just open the throttle in neutral & the limiter will prevent you from overreving it, the sound will be there but you won't experience the power loss. __________________ White Trash Hick from Appalachia

03-26-2010, 09:07 AM	#6
A Star Ride Registered Member Join Date: Oct 2009 Location: central Va Posts: 1,126	You said single speed engine, sorry. Your probably already at the top speed the bike is designed to go. You can disable the limiter, but your asking for trouble if you do. __________________ White Trash Hick from Appalachia

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03-26-2010, 09:55 AM	#7
Kenneth_Moore Registered Member Join Date: Jun 2007 Location: VIsiting the GIft Shop in the Pit of DIspair Posts: 7,118	An 88cc bike with a 50cc engine. Maybe you should get a bigger bike. __________________ www.kennethmoore.org

03-26-2010, 10:03 AM	#8
mscuddy MODERATOR X Join Date: Jun 2007 Location: Next to my still checkin the temp. Posts: 5,444	Is it a two or four stroke? If it's a two stroke, and you have performance parts on it (chamber, ported cylinder, etc) you will have to either raise the needle in the slide to get more fuel in the motor at full throttle, or get a bigger main jet. If it's a four stroke, throw it away. __________________ A gun is a tool, Marian; no better or no worse than any other tool: an axe, a shovel or anything. A gun is as good or as bad as the man using it. Remember that.