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Discussion Starter · #1 · (Edited)
Hi everyone

I recently had a x15 and im wondering if it possible to reduce some vibration when im driving it. The vibration is from the engine and its more than my x7 2stroke. Its realy anoying. And i would like to know if its normal that the gear sometime wouldnt engage and when i put in first the bike kick foward. I dont know much about the 110cc but i know that the 125cc lifan for dirt bike dont make that much vibration so if its not gonna be better i will swap a 125cc in it.
 

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Are your motor mount tight? Or are your holes in the frame mounts oblong letting the engine vibrate?
 

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Hi everyone

I recently had a x15 and im wondering if it possible to reduce some vibration when im driving it. The vibration is from the engine and its more than my x7 2stroke. Its realy anoying. And i would like to know if its normal that the gear sometime wouldnt engage and when i put in first the bike kick foward. I dont know much about the 110cc but i know that the 125cc lifan for dirt bike dont make that much vibration so if its not gonna be better i will swap a 125cc in it.
sounds like you need to readjust your clutch right or youre gonna need a new clutchpack....Good Luck
 

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whenever I put my bike in first gear it lunges forward a little bit........... so I just push forward a little bit as I'm shifting into first and no problem.......along with the motor mounts being oval shape is there anything to do to fix that problem I also have that on my upper motor mounts I was just thinking weld a few tacks inside the hole in call it good
 

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Discussion Starter · #5 ·
I can see the engine moving so i know that the engine mount is weak but what i understand on engine vibration is that wathever how hard it is mount if the engine has a crankshaft not balanced it will vibrate.. What i want to know is if i can do anything to the engine.. And btw i was wondering if a extended swingarm will make the bike handle better cause im 6'2" 180 lbs.
 

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whenever I put my bike in first gear it lunges forward a little bit........... so I just push forward a little bit as I'm shifting into first and no problem.......along with the motor mounts being oval shape is there anything to do to fix that problem I also have that on my upper motor mounts I was just thinking weld a few tacks inside the hole in call it good
I squirt PL black poly-eurethane into the engine mount holes,,when the eurethane hardens it acts as a shock absorber and takes away the extra clearance...Your holes may of oblonged large enough to install two 3/8" bolts through the engine now.......Torquing is 130ftlbs for the engine mounts........
 

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you should drill the motor and frame to 3/8s and replace the two bolts with grade8 stuff
that stops most of the vibration but be aware that a single piston at 10k is gonna shake a bit
ive had one odd issue with a 110, it would vibrate only in a range really bad, eventually i took the head off to look and one of the C clips that hold the piston rod in place had embedded itself in the groove too much and the wrist pin walked out about 2mm, that was enough to upset the engines balance, and it left to big score marks on the cylinder wall...crazy, put in a new clip and took that motor to sandy hook in the risisng sun bike, ran like a champ
 

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In a 4 stroke you can run teflon buttons instead of piston clips, my 4 cyld 836cc modded Honda had buttons in the 11:1 Wiseco pistons.
 

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from my experiance the extended swingarms make the bikes handle worse than they do now
well more stable in a straight line but cornering is def worst plus it lowers the bike also
the shorter wheel base the better for handleing
i have not yet had one of these small bikes with the extended arm but i have rode a few big bikes a zx10 954rr and gsxr1000 all with extended arms and thats my take on it
 

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from my experiance the extended swingarms make the bikes handle worse than they do now
well more stable in a straight line but cornering is def worst plus it lowers the bike also
the shorter wheel base the better for handleing
i have not yet had one of these small bikes with the extended arm but i have rode a few big bikes a zx10 954rr and gsxr1000 all with extended arms and thats my take on it
My X15 dragbike with 10" stretch didnt handle that bad...I needed to add almost 150 psi air pressure to the airshock I had on it though because more stretch adds more cantilever.........
 

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Discussion Starter · #12 · (Edited)
Ok some update !
The vibration with the frame and the engine drilled to 3/8 with grade 9 aircraft bolt the engine continue to vibrate like hell. But when i was drilling the frame ive seen that the bike was crashed bye the first owner ! Not a big crash just like a funny fail loll but the braket that hold the fairing was bent. That was the reason for the annoying vibration sound ! After i had repair this wow the difference ! No more vribration sound or something that make think other people that my bike will fall apart loll.. So i continu to have a vibration but who cares if its just un my butt loll.. Anyway i found that the stock gearing is NOT for riding in street its only for racing at the track. even with a stock bike the best gearing and the best mod for under 20$ is put a 17t on the front instead of the 14t and it make my riding more snooth because the engine rev lower in rpm. When ive got the bike stock it goes 40-42 mph with the 14/38 gearings and that with my gps mounted on the gopro mount. So i will make a another test today to see how much top speed can a stock x15 with 17/38 gearing...
 

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Youll most likely get 51-52mph out of it..............Nice job eleviating the vibes but as I said the chinese just slap these engines together,,, nothing is blueprinted...if you took the time to totally disassemble the engine and deburr/radius,,regrind,,lighten,,harden,port and balance everything youll be amazed at how smooth the engine runs and revs up,,,The topend speeds will be alot higher too aswell as an increase in gas mileage.........My X15 and X18 were mindblowing animals for super modded stock engines......My X18 was geared 14/38 for stunting and it was hitting 60 and revving out over 13,000rpm's...
 
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