2-Stroke 49cc Engine Help!! - Pocket Bike Forum - Mini Bikes
 
LinkBack Thread Tools
post #1 of 17 (permalink) Old 06-27-2009 Thread Starter
verified
 
Join Date: May 2009
Age: 25
Posts: 12
2-Stroke 49cc Engine Help!!

O.k., I have a problem in which is confusing me alot. I have a 49cc engine in a pocket bike that my friend gave me, the problems with it are that when i am trying to use the pull start, the pull start will be extremely hard to tug at, as if the gears were having a hard time turning, and i was going at it for about 5 minutes trying to get it to start but the engine wouldn't start. My friend says that when it does start though, the engine will be smoking, which i am told means it has to much oil in the two stroke, which in my opinion doesn't make sense because the gas has a reddish tint and smells alot like gas rather then 2-stroke Oil+gas. My friend had taken out the orriginal clutch inside the motor and switched it out with a better one, could that have anything to do with it? Do i need to add in more gear oil above the sprocket piece?
khris91 is offline  
Sponsored Links
Advertisement
 
post #2 of 17 (permalink) Old 06-27-2009
PBP SENIOR MEMBER
 
Blind909's Avatar
 
Join Date: Feb 2009
Age: 22
Posts: 267
Re: 2-Stroke 49cc Engine Help!!

it has nothing to do with the sprockets, or the clutch, unless the clutch is adjusted so much that it is fully extended. Try lifting up the back end, so the wheel is off the ground, and try again. If it starts, and the back wheel moves, it is a clutch prob. otherwise, if he wasnt using oil, you could have seized the motor, and will need a top end rebuild kit.

GP RS-R Drag Bike-first and only bike. Mods are-
Champion sparkplug, led neons, headlights, tail lights, 7/60 gearing, round aluminum foot pegs, stretched swing arm, UFO air filter, gas cap breather, completely home made drag pipe, Petcock mod.
Blind909 is offline  
post #3 of 17 (permalink) Old 06-27-2009 Thread Starter
verified
 
Join Date: May 2009
Age: 25
Posts: 12
Re: 2-Stroke 49cc Engine Help!!

Ok please explain something cause im still new to alot of this, What does it mean when the engine is seized, what exactly is wrong in it?
khris91 is offline  
Sponsored Links
Advertisement
 
post #4 of 17 (permalink) Old 06-27-2009
PBP SENIOR MEMBER
 
Blind909's Avatar
 
Join Date: Feb 2009
Age: 22
Posts: 267
Re: 2-Stroke 49cc Engine Help!!

When you dont use enough oil, the engine has no form of lubrication, and it will get hot, and possibly melt the piston.. This is why you have to use oil, so if you do get a rebuild kit, make sure you use 2 stroke oil and gas. I dont know how to explain it further, other members may be able to tho.

GP RS-R Drag Bike-first and only bike. Mods are-
Champion sparkplug, led neons, headlights, tail lights, 7/60 gearing, round aluminum foot pegs, stretched swing arm, UFO air filter, gas cap breather, completely home made drag pipe, Petcock mod.
Blind909 is offline  
post #5 of 17 (permalink) Old 06-27-2009
PBP SENIOR MEMBER
 
thestone11's Avatar
 
Join Date: Jul 2008
Posts: 1,886
Images: 15
Re: 2-Stroke 49cc Engine Help!!

Quote:
Originally Posted by Blind909 View Post
it has nothing to do with the sprockets, or the clutch, unless the clutch is adjusted so much that it is fully extended. Try lifting up the back end, so the wheel is off the ground, and try again. If it starts, and the back wheel moves, it is a clutch prob. otherwise, if he wasnt using oil, you could have seized the motor, and will need a top end rebuild kit.
Usually when the rear wheel spins after you started the bike is the idle is set too high. As far as oil mixture, you have to mix it at 32:1. There are things that you need to check if the bike doesn't want to start:

1) make sure you turn the gas knob on
2) play with the choke
3) make sure you have gas in the system, fuel line and tank are not clogged
4) open up the float bowl and check whether you have a nice flow of gas to the carb.
5) check and make sure you are getting sparks (healthy sparks should be blue in color)

Heavily Modded Lucky 7!
Polini 911 rep with real polini racing pipe, polini clutch with red springs, polini 80mm bell, real dellorto 14/14L, GRC quick turn Throttle, Black widow reeds, polini gas tank and coolant bottle.
http://s538.photobucket.com/albums/f.../My%20Minimoto
thestone11 is offline  
post #6 of 17 (permalink) Old 06-28-2009
Hooligan
 
SpyGuy's Avatar
 
Join Date: May 2008
Posts: 8,578
Images: 23
Re: 2-Stroke 49cc Engine Help!!

If he truly seized the engine, you wouldn't be able to pull the starter at all. Mix up some 32:1 gas/oil and try it. You can find little bottles of 2-stroke oil at AutoZone or Checker that you would just mix with a gallon of gas. Two-stroke engines smoking is normal - you're burning oil as well as gas.

"I'm going off the rails on a crazy train." - Ozzy Osbourne

Dear haters: Please be patient. I have so much more for you to be annoyed about.
SpyGuy is offline  
post #7 of 17 (permalink) Old 06-28-2009 Thread Starter
verified
 
Join Date: May 2009
Age: 25
Posts: 12
Re: 2-Stroke 49cc Engine Help!!

So wait, you think its the gas? and how would i check the spark plug? Also, if i were to take out the pull start and try to move the piece that the pull start spins, would it spin if the engine was seized?
khris91 is offline  
post #8 of 17 (permalink) Old 06-28-2009
verified
 
BluBandit's Avatar
 
Join Date: Jun 2009
Posts: 16
Re: 2-Stroke 49cc Engine Help!!

If you were to remove the pull start and try to rotate the part inside there, if it's siezed it will not spin. Siezing is when the piston has gotten so hot inside the cylinder that it has actually swelled in diameter to the point that it cannot slide up & down any more. And, once siezed, you will have a tough time breaking it free to get it to working again, plus very considerable damage may have taken place inside the motor due to the lack of oil. LUBE IS YOUR FRIEND, without it, you wont like the results! No need to over-do-it, just keep it mixed properly and you should be okay.
BluBandit is offline  
post #9 of 17 (permalink) Old 06-29-2009
Super Moderator
 
StrayDawg63's Avatar
 
Join Date: Nov 2004
Age: 53
Posts: 6,162
Re: 2-Stroke 49cc Engine Help!!

Quote:
Originally Posted by khris91 View Post
O.k., I have a problem in which is confusing me alot. I have a 49cc engine in a pocket bike that my friend gave me, the problems with it are that when i am trying to use the pull start, the pull start will be extremely hard to tug at, as if the gears were having a hard time turning, and i was going at it for about 5 minutes trying to get it to start but the engine wouldn't start. My friend says that when it does start though, the engine will be smoking, which i am told means it has to much oil in the two stroke, which in my opinion doesn't make sense because the gas has a reddish tint and smells alot like gas rather then 2-stroke Oil+gas. My friend had taken out the orriginal clutch inside the motor and switched it out with a better one, could that have anything to do with it? Do i need to add in more gear oil above the sprocket piece?
You need to adjust the coil as it's rubbing on your flywheel which is making it hard to pull the pull starter. What oil to gas ratio are you mixing you fuel at? Oh just saw that a new clutch was put on. Now this may not be the problem but if when putting the new clutch on if the woodruff key in the crank slipped out of the groove when the clutch was slipped onto the crank it maybe wedged inbetween the clutch and the crank case. But check the coil first.
StrayDawg63 is offline  
Hooligan
 
SpyGuy's Avatar
 
Join Date: May 2008
Posts: 8,578
Images: 23
Re: 2-Stroke 49cc Engine Help!!

Good call on the coil being misgapped, Dawg.

The airgap between coil and flywheel should be the thickness of a standard business card. Loosen the coil, put a business card in there, put the coil down against the card so it's snug, and tighten up the coil. Rotate the flywheel to get the card out.

"I'm going off the rails on a crazy train." - Ozzy Osbourne

Dear haters: Please be patient. I have so much more for you to be annoyed about.
SpyGuy is offline  
PBP RACER
 
Join Date: Apr 2008
Age: 31
Posts: 56
Re: 2-Stroke 49cc Engine Help!!

^^^^ This gonna help me as well...nice post glad I found it )
business card gap.


(soon to be running again x1!)
porsche23 is offline  
verified
 
Join Date: Apr 2012
Age: 23
Posts: 5
Re: 2-Stroke 49cc Engine Help!!

You post a pic of it? I have a pocket bike and I have no info on it but I'm wondering if you have to same one as me.
VIP854 is offline  
EPR
Outlaw
 
EPR's Avatar
 
Join Date: Aug 2009
Posts: 21,969
Re: 2-Stroke 49cc Engine Help!!

These are old threads. If you cylinder is out forward & your clutch and flywheels are on opposite sides you have a 47 or 49cc reed port engine. If the cyld is straight up and down and the flywheel and clutch are bolted together you have a 43 to 49cc piston port engine. The coils look alittle different but you adjust them the same.

Empty Pockets Racing: The difficult we do, the impossible takes longer.....
EPR is offline  
verified
 
jtarziers's Avatar
 
Join Date: Mar 2012
Posts: 35
Images: 1
Re: 2-Stroke 49cc Engine Help!!

looking for torque specs for 49cc cag. motor? anything? anywhere?
jtarziers is offline  
EPR
Outlaw
 
EPR's Avatar
 
Join Date: Aug 2009
Posts: 21,969
Re: 2-Stroke 49cc Engine Help!!

Use lock washers and 8.8 grade bolts and tighten them with a small wrench.

Empty Pockets Racing: The difficult we do, the impossible takes longer.....
EPR is offline  
EPR
Outlaw
 
EPR's Avatar
 
Join Date: Aug 2009
Posts: 21,969
Re: 2-Stroke 49cc Engine Help!!

Porsche23, have you ever seen a Porsche 16 cylinder fuel injected Can Am engine? Look at the 16 lines coming off the pump, what nightmare that could be. your going to Love this.
Attached Images
File Type: jpg CanAm 16 Cyld German Engine.jpg (75.4 KB, 11 views)

Empty Pockets Racing: The difficult we do, the impossible takes longer.....

Last edited by EPR; 04-12-2012 at 04:21 PM.
EPR is offline  
verified
 
jtarziers's Avatar
 
Join Date: Mar 2012
Posts: 35
Images: 1
Re: 2-Stroke 49cc Engine Help!!

Sorry should've been more specific. Bought that prebuilt cag 44mm engine off ebay. I'm Sure everyone knows bout it... everything i been reading makes me Wonna make sure its all good.
jtarziers is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pocket Bike Forum - Mini Bikes forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome