GT7 Pro Racing Motor

[Bullet3082]

I purchased from Motor King a GT7 Pro Racing motor when it finally arrived. They didn't ship the cylinder or piston with the motor all they shipped to me was the crank and a cnc racing head. Now my states attorney general is going to go after them, told them I will more than likely sue motor Kind for fraud. but I get a head of myself, This is what I did I went to amazon and ordered a piston for a 66/80 cc engine and a cylinder. I put it all together and the piston hit the head and doesn't not cycle!
I am banking that not all here are morons like motor king, so can some one tell me what might be causing this problem other than they didn't send me the motor I ordered?

 

[darwin]

What does your order receipt say? Does it say complete motor? Does it say crank and head on it? If you paid by CC dispute the charges. Don't dance around any other issue than what was sent is useless to you and you want your money back. Don't say you might be able to use anything, then they'll want to give you a % of your money back. You wanted/expected a complete motor PERIOD and you did not receive one.

 

[Bullet3082]

I ordered a complete kit for a bicycle, to make it a gas bike!

 

[crassius]

first, don't get all excited and get ahead of the process - there are steps to take in a certain order to get things like this straightened out

start with the agency that processed the payment (bank or credit card or paypal or ...)

save a snapshot of the order page or advertised product or web page

-----------------------

if you want help here, you should at least post a link to what you ordered

as far as piston hitting head goes, do you realize that there are high wristpin pistons and low wristpin pistons which make about 5mm diff in how high they sit? you may have ordered wrong one for that motor (and possibly wrong cylinder too)

 

[Bullet3082]

This is what I ordered and I got everything but the cylinder, piston and rings!

GT7 Pro Racing 66cc/80cc Bike Engine Kit - Description

*Minimal assembly required.

These GT7 Pro Racing 66cc bicycle engine kits give 3.85 HP “the little powerhouse engine of the industry.”


3.85 HP 2 cycle gas/oil mix bike motor kits. GT7 Pro Racing 66cc/80cc Bike Motor Kit: 1/2 gal. gas tank, chain and sprocket, handlebar controls, mounting hardware package and instruction sheet. Total wt. is 24 to 27 lbs.


Starting your GT7 Pro Racing 66cc/80cc Bike Motor Kit (Standard Finish): Pedal normally or use engine power at your option. The engine starts quickly when the handlebar clutch lever is released while pedaling. Twisting the throttle controls the speed to 45 mph. Speed depends on rear sprocket ratio and weight of rider.


GT7 Pro Racing 66cc/80cc Bike Motor Kit (Standard Finish) fits best on bikes with 25 to 30mm diameter 70 degree Vee type frames but can be installed on larger diameter tube frames with modifications. “Looks Cool” on the older cruiser type coaster brake bikes.
This bike motor kit comes with everything that you'll need except gas and oil! You will be able to stop or start the engine as you ride. There is no rope pulling needed and it gives more speed and gets around 150 miles on a gallon of gas. Please Tell a Friend about this product and help spread the word about Motorized Bicycles.

Get your GT7 Pro Racing 66cc/80cc Slant Head Bike Motor Kit (Standard Finish) now while supplies last at this price.

Bicycle Motor Engine Kit Includes: (View Larger Image)​

1. GT7 Pro Racing 66cc/80cc Motor
   3.85 HP
2. WITH RACING CNC CYLINDER HEAD - $90 VALUE!
3. With GT80 Reed Valve & Keihin Carburetor Clone Assembly - $60 VALUE!
4. Friction Clutch; Pedal Start
5. Magneto With Solid State CDI Ignition
6. 44Tooth, 9 Hole Chrome Sprocket
7. 3 Plate Sprocket Kit
8. 2.0 Liter Fuel Tank, Tear Drop Shape (Black Color)
9. Chrome Muffler
10. Push Button Clutch Lever And Cable
11. Twist Throttle With Engine Kill Switch
12. Improved Gas Valve
13. Fuel Line #2
14. Idler Pulley Chain Tensioner with Bearings
15. Chrome Lined Cylinder Wall
16. Head With Center Fire Spark Plug
17. 202 Crankcase Bearings
18. Needle Bearings On Piston Wrist Pin
19. Improved 415 Chain
20. Chain Guard
21. Tool Kit
22. All The Mounting Brackets, Gaskets, And Hardware Including Nylon Locking Nuts
23. Universal Motor Mount
24. Complete User Manual
25. 6-Month Limited Warranty Included - FREE
26. Extra Standard Slant Cylinder Head

 

[FNTPuck]

That kit is supposed to come with the cylinder and piston. They will send one if you email them...but it could take MONTHS of emails and complaining. Their service is terrible.

Few issues with that kit coming from someone who made the mistake of ordering it themselves. I had already built two or three stock kits at the time and thought I was ready for something more serious but if I could go back I would not have ordered it.

- First is that it comes with a reed box, but no windowed piston. I emailed to ask before purchase if it came with a windowed piston since it has a reed box, but never got a response. That should have been my first red flag but I purchased it anyway. Without a window on the piston, the reed box is basically just an intake restriction. Removing the pedals from it while testing increased performance. The proper thing to do is to window the piston or replace it with a windowed piston from zeda/mzmiami/etc.
- Next issue with that kit is that the carb is nowhere near correct out of the box for these motors. First, the throttle cable end is too short. I had to remove some of the cable sleeve to make the slide portion longer. Then, it ran like crap. Removing the reed pedals from the box helped(non-windowed piston), but the jetting was still way rich so I purchased the full jet kit and for the life of me could not get it to run right with the included carb. Replacing the whole carb and reed box assembly with a stock rejetted NT carb+ offset intake increased performance everywhere.
- Third issue is the "Racing" CNC head. While it does look great and helps the motor run cooler, it actually lowered compression. I had to sand down the squish band to restore it back to proper compression.

Long story short, you can make that kit work without spending a ton of money but you need to remove the whole $60 carb and reed box for a rejetted stocker then get the head milled down some to restore lost compression. Since you are wasting the biggest part of the kit (reed box +carb), need to work on the head, and still ending up with a poorly balanced motor, you are much better off spending the $180 on a Zeda Triple40. They make more power, come with the upgraded stainless allen hardware, have better quality control, and they all now include balanced cranks which I can say from experience are a HUGE improvement at high RPM and will likely help the bearings last longer.

I still have the carb lying around in a box somewhere which I will probably put on one of my Triple40s that actually make enough power to need a bigger carb.

 

[Street Ryderz]

This is what I ordered and I got everything but the cylinder, piston and rings!

GT7 Pro Racing 66cc/80cc Bike Engine Kit - Description

*Minimal assembly required.

These GT7 Pro Racing 66cc bicycle engine kits give 3.85 HP “the little powerhouse engine of the industry.”


3.85 HP 2 cycle gas/oil mix bike motor kits. GT7 Pro Racing 66cc/80cc Bike Motor Kit: 1/2 gal. gas tank, chain and sprocket, handlebar controls, mounting hardware package and instruction sheet. Total wt. is 24 to 27 lbs.


Starting your GT7 Pro Racing 66cc/80cc Bike Motor Kit (Standard Finish): Pedal normally or use engine power at your option. The engine starts quickly when the handlebar clutch lever is released while pedaling. Twisting the throttle controls the speed to 45 mph. Speed depends on rear sprocket ratio and weight of rider.


GT7 Pro Racing 66cc/80cc Bike Motor Kit (Standard Finish) fits best on bikes with 25 to 30mm diameter 70 degree Vee type frames but can be installed on larger diameter tube frames with modifications. “Looks Cool” on the older cruiser type coaster brake bikes.
This bike motor kit comes with everything that you'll need except gas and oil! You will be able to stop or start the engine as you ride. There is no rope pulling needed and it gives more speed and gets around 150 miles on a gallon of gas. Please Tell a Friend about this product and help spread the word about Motorized Bicycles.

Get your GT7 Pro Racing 66cc/80cc Slant Head Bike Motor Kit (Standard Finish) now while supplies last at this price.


Bicycle Motor Engine Kit Includes: (View Larger Image)

1. 
   
   • GT7 Pro Racing 66cc/80cc Motor
     3.85 HP
   
   
   • WITH RACING CNC CYLINDER HEAD - $90 VALUE!
   
   
   • With GT80 Reed Valve & Keihin Carburetor Clone Assembly - $60 VALUE!
   
   
   • Friction Clutch; Pedal Start
   
   
   • Magneto With Solid State CDI Ignition
   
   
   • 44Tooth, 9 Hole Chrome Sprocket
   
   
   • 3 Plate Sprocket Kit
   
   
   • 2.0 Liter Fuel Tank, Tear Drop Shape (Black Color)
   
   
   • Chrome Muffler
   
   
   • Push Button Clutch Lever And Cable
   
   
   • Twist Throttle With Engine Kill Switch
   
   
   • Improved Gas Valve
   
   
   • Fuel Line #2
   
   
   • Idler Pulley Chain Tensioner with Bearings
   
   
   • Chrome Lined Cylinder Wall
   
   
   • Head With Center Fire Spark Plug
   
   
   • 202 Crankcase Bearings
   
   
   • Needle Bearings On Piston Wrist Pin
   
   
   • Improved 415 Chain
   
   
   • Chain Guard
   
   
   • Tool Kit
   
   
   • All The Mounting Brackets, Gaskets, And Hardware Including Nylon Locking Nuts
   
   
   • Universal Motor Mount
   
   
   • Complete User Manual
   
   
   • 6-Month Limited Warranty Included - FREE
   
   
   • Extra Standard Slant Cylinder Head

This is a commen occurance since their not allowed to bring in 2 stroke engine's so they are shipped with the top end seperately to avoid the E.P.A. and customs from seizure of shipment.Some vendors will assemble it prior to shipping to end user and some just send the two seperated boxes.So you went ahead and ordered a cylinder and piston that don't match the geometry of the engine and now have clearence issues, hang on to that cylinder and piston as it may come in handy at some point.You need a high pinned piston and a cylinder with it's intake port (window) retimmed for a reed and windowed piston,many also have a booster port or third transfer and a trench below the intake to improve feed.Also in the product description above it claims 3.85 hp and that's not true at all! you'd be lucky if it made 2 hp out of the box probably a bit less,they require porting and a good tunned pipe to make the claimed hp.

 

[Bullet3082]

ya FNTPuck! I ordered a better carb for it and a throttle cable that came with a dual brake pull. I also ordered a different exhausts, that is a BBR Tuning Deluxe high performance Expansion chamber. Those little 2 stroke engines perform better if the breath proper. I am not expecting anything from King Motor that dealer is a joke. I will say nothing good about them you order a motor kit from the that say little minimal assembly required why send the motor taken apart and with no cylinder and piston. King Motor are real morons!

 

[MotorBicycleRacing]

More $90!! Deluxe high performance junk from Bikeberry.
The small diameter header on the pipe restricts it.

https://www.amazon.com/BBR-Tuning-Performance-Expansion-Chamber/dp/B0778ZX312

 

[Bullet3082]

was looking on amazon for piston does anyone know about this piston:
https://www.amazon.com/CDHPOWER-80c...+Piston+Set+-+66cc/80cc+Gas+Motorized+Bicycle