R50X power under load issues and questions.

[wapezoab]

I just bought a 2007 TGB R50X and its been upgraded to a 70cc. I don't have much info on any other things done to it. The problem i have is power under load. When i first took it out it would go to around 25mph then drop out like it lost fuel. It would die also. I purchased a CDI and adjusted the carb and now it wont go a block then starts losing power and dies then it doesn't want to start but does finally start after a few minutes. When i had it on the stand it seemed to run and rev up decent but the idle would go up and down around 2 or 3 thousand rpms every few minutes. I took the carb out and checked the float and it was off a little. I also have a few questions about scooters or this one its my first and i don't know much about 2 stroke engines. I almost think this is a fuel issue/carb adjustment but i was also concerned about belt wear. The odometer shows 7500 that's on everything but the engine.
Also have other concerns about starter issues i will post after i get it running better. I wont start using the electric starter periodically. Just to make sure i cover everything the oil mixture line to the carb has been disconnected and fuel is being pre mixed. I just want to get it running and then if i need to make upgrades due to going from 49cc to 70cc i will.

Does it have a fuel filter? I see a silver component a little beyond the gas tank but i don't think that's it?

How can i test the coil other than a visual spark?

What are go starting settings for adjusting its Mikuni carb. How many turns in or out for the idle and fuel mixture screws?

What should i gap the plug for 70cc engine?

Are there any places to buy a shop/service manual that would be helpful?

Looks as if the emission system has been removed if it goes on the right side opposite the kick start. Is this going to affect the performance in a negative way?

A good online parts store would be great.

I hope i didn't make a mistake buying this scooter. I am on disability and limited income and its my only transportation. Thanks in advance. Any feedback would be appreciated.

[harry]

welcome wapezoab,

so look for the service/parts manual links at the bottom of the forum home page
 for starters
 
at 7500 miles you should put in a new belt , let me know when your ready for it
and i can send it to you or anything else you need.
 
 the silver thing  should be a shut off valve and after that should be a white/clearish
filter .

 clean the carb really good... the jets & passages  should be clean!
 plug gap should be the same as stock   but use a 8 or 9 , not the 7! which is too hot and
will seize the motor!  also check what size jets you have in the carb and get back to me.

set the air screw to  about 3/4 - 1 1/2    idle about 2  turns out  and
 re adjust when the motor is warm  remember that bu adding oil to the tank
you are leaning out the mix so look for a dark brown plug color!

 many times the starting motor doesn't work with the 70cc kits....

you should get about 42 mph with a kit 

oilyhans

[wapezoab]

The plug i took out of it was a brownish color. I am going to start from scratch on the carb adjustment and go from there. When you are referring to 8 or 9 instead of a 7 are you meaning what kind of plug? Also what jets should i be using in the carb for the 70cc upgrade. I am new to all this but i am a good learner so sorry for all the questions.

Is there a way to test the coil because i suspect it might be a issue?

Thanks and if i do need parts i will check you out. I will also be ordering the belts as funds permit.

[wapezoab]

I set carb as said in previous post. Idle screw is out further. Scooter starts and runs but rpm fluctuates then dies after a minutes and it has to sit for a bit before it will start again. Is starvation a issue? I am pulling my hair out.

Thanks for any feedback.

[harry]

idle should be set when motor is warm  and the rear wheel
should just start to move.
 you might need to clean the idle and the choke passages...

 also it is unknown what size jets you have in the carb? since its a 70 kit you need
bigger than stock , plus is that a stock carb?

oilyhans

[wapezoab]

Yes i believe the carb is stock and i have been searching for jets but no luck. The numbers on the carb dont help in a web search to tell what type or series it is. I got it running sounds good but wont run over 10mph and bogs down and if i feather the throttle i can keep it running. I will like to order the jets today if i can find them. I also bought a hotter plug to try today. I will let you know how that goes. I can post pics of the carb if needed but here are some of the numbers on it.

IIF-45
CP1
16-5680

These might not be right cause its hard to see them.

I also checked for leaks and found some loose bolts on the exhaust header.
I will post the pictures of the carb and jets in the next post.

Thanks for everything.

[wapezoab]

Mikuni Carb pictures fron a 2007 TGB R50X.

http://imageshack.us/photo/my-images/836/carbsideinlet.jpg/

http://imageshack.us/photo/my-images/37/carbmixside.jpg/

http://imageshack.us/photo/my-images/62/carbjetstopview.jpg/

http://imageshack.us/photo/my-images/72/carbbothjetssideview.jpg/

http://imageshack.us/photo/my-images/829/carbcp1number.jpg/

http://imageshack.us/photo/my-images/547/carbiif.jpg/

http://imageshack.us/photo/my-images/40/carbside2.jpg/

http://imageshack.us/photo/my-images/16/pictureogj.jpg/

Hope this helps. I will try to read the numbers on the jets and get back here later. I included a picture of the scooter.

Thanks in advance.

[harry]

well if you ave a stock carb & jets ,your jets are too small for a 70 kit

also a hotter plug would blow up your scooter ,you want cooler plugs
 what is the number of the plug you have now? and the new one?

i have all the main & idle jets you would need,
 let me know and i'll send them out today and you should see
them round about tuesday next week.


 oilyhans

 ps i sent you the pm on provo

[wapezoab]

The main jet is a 70 and the pilot has 22.5 on it. I need to go up on the main jet correct? Someone said to get a NGKBR8HIX?
The plug was a NGK BP7HS.
The ones they said at the auto parts store that would match the NGK are...Autolite 4092 they said would match a NGK BP8HS - for a hotter plug.
The NGK7HS was matched to a Autolite 4123 for the original replacement or cooler plug.


Can you let me know how to find the correct parts on that site? I am just not familiar with it. Also can you let me know what size main and pilot jets i need? I will place the order today if i get that info.

Thanks for your help!

[harry]

the 7 is the stock plug and too hot for the 70cc kit. if you
run it too long with that plug you will seize the motor.

on NKG plug  the bigger the number the cooler the plug.
on all other plugs the bigger the number the hotter the plug.

a pm is on the way

oilyhans

[wapezoab]

The ones i have are 70 main jet and 17.5 idle. Can you direct me to the idle jets in a pm?
Also if you could send me the info for a coil, rollers, and rear brake pads that would be great?
I am also in the market for a left hand mirror and some good 2 stroke oil?

If this is the stock coil just reply and i will purchase it also? While i am at it i prob need a cvt belt?

https://whidbeyislandmoped.com/cart/index.php?main_page=product_info&cPath=17&products_id=145&zenid=a065cb82e937f4a7acb5806d6ae497b7



Thanks

[wapezoab]

Update...I bought a compression testing kit and plan on a test later today. I was worried about the sound of the motor after it warmed up and the bogging down under load issues i have.

[harry]

anything above 115  is ok, below 100 you have trouble

 if you check your plug with a magnifying glass and
find any tiny balls stuck to the electrode or ground strap
 you had a soft seize

a rattling sound coming from the motor when its revved
is a bad bottom bearing 

oilyhans

[wapezoab]

Compression test showed 155 psi...sheeeew. I was worried. It started right up and idled great today so I am at a complete loss. Guess I will try the new jets when they get here this week. I thought somewhere I read that I should have a 760 main jet but I dont its a 70 main jet? So I guess I will go up to a 72.5. I guess I should have ordered a 75 main.

Could I have issues with the vacuum fuel shut off valve? I think im close when I say that.
Im also worried about the coil or also the magneto or what ever its refered to on a 2 stroke?

I greatly appreciate the help given. Have a great day!

Thanks

P.S. The spark plug looked real good as in color.

[wapezoab]

For anyone following this thread.

I got it running after changing to the 20 pilot and the 72 main but it wont go over 25 and loses power. The air adjust screw is only open a 1/4 turn so im going to go up on it and maybe up on the main.
I bought a new battery here also.

Thanks Harry!