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Discussion Starter · #1 ·
Have a Icebear Fuerza 125cc.. 297 miles. Bought brand new. Been running great until a few days ago I noticed a gas leak in fuel sending unit. Fixed that but in 4th (4 speed) it jerks as accelerating, and I mean hard. Doesn't want to go but it will and it's rough. Changed oil at 225miles. Cleaned carb after all this, chain lube and spark plug. Still doing it. Played with the choke at different openings, no go.. now I have no clue.. thoughts????
 

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Need to know at what revs is it jerky. Most bikes will be jerky at low revs in fourth, especially the small ones. You may need to wring its neck.

UK
 

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I forget, are you running the factory carb or a Mikuni one? Sometimes those factory carbs cause issues no matter how clean they are.

Also make sure your chain and sprockets are tight. Chain slack is supposed to be 15-20mm on the GLVs (Grom Like Vehicle). Any more and you can get jerking/hesitation.
 

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Discussion Starter · #5 ·
I forget, are you running the factory carb or a Mikuni one? Sometimes those factory carbs cause issues no matter how clean they are.

Also make sure your chain and sprockets are tight. Chain slack is supposed to be 15-20mm on the GLVs (Grom Like Vehicle). Any more and you can get jerking/hesitation.
Mikuni is on delivery along with intake and jets and mid pipe, so factory as if now. And I was wrong. Its actually 6000 rpms it starts and it could possibly be the chain and sprocket. I'll check when I'm off.
 

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If this is a brand new bike, why are you fiddling with everything that makes it go? I'm thinking you have it so screwed up with all the stuff you've fiddled with that you need to look hard at getting back to square 1. That's too few miles to be having this many problems. You changed oil already. Seems way too soon but okay. Are you sure you put the correct oil in. Could you be getting clutch slip?
 

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Discussion Starter · #7 · (Edited)
I didn't "fiddle" with anything but oil. And it was recommended to changed at first 300miles so I did so at 225.. After this drove til 297miles and at this milestone is when the problem occurred there for contacted where I got it. They recommended spark plug so I did, tried the carb cleaner just to see if itd help, it didn't and chain lube was also recommended at 300miles so I did so.. And adjusting the choke to different positions isn't really fiddling.. haven't done anything else to the bike mod was yet period.. place I bought from also said maybe then cdi chip so they're sending me a new one but as of now.. It's still doing it. And yes used the correct oil. Don't think the oil would have anything to do with it especially after another 75miles later this happened.
 

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I have never heard of a sprocket or chain slipping? if this is what it feels like I think hogcowboy may be correct sounds more like a clutch issue!
 

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Discussion Starter · #9 ·
I don't know how the break down of the clutch actually works if someone could explain how this could be the problem. I mean it doesn't slip out of gear, shifts fine, no grinding, it's just when I reach 5500-6000rpms it jerks and won't push past that rpm
 

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Just a shot in the dark here. If the engine is a Honda/Grom clone, there may be a motorcycle specific oil that that engine will accept because the clutch plates run in the same oil used by the engine.

The wrong [fuel saving] oil like used in cars may cause the clutch to shudder. Any Honda that I have ever used likes oil that has JASO rating.

I use Rotella T-6 synthetic as it is less expensive than the oil you buy at a bike store and has the JASO rating. Check your manual to see which range of oil the manufacturer recommends.
 

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Discussion Starter · #11 ·
Just a shot in the dark here. If the engine is a Honda/Grom clone, there may be a motorcycle specific oil that that engine will accept because the clutch plates run in the same oil used by the engine.

The wrong [fuel saving] oil like used in cars may cause the clutch to shudder. Any Honda that I have ever used likes oil that has JASO rating.

I use Rotella T-6 synthetic as it is less expensive than the oil you buy at a bike store and has the JASO rating. Check your manual to see which range of oil the manufacturer recommends.
It is a honda grom clone. Not a honda engine of course. It is not fuel injected like the grom, it's carburated. This is what I used *pic* and remember this happened 75miles after the oil change. I wouldn't think itd take that long to cause effect on anything but you guys tell me lol
 

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Does the issue ONLY occur in 4th gear at that rpm? Does it not occur in any other gear at that rpm? If is't only 4th gear then you may have a cracked tooth on a transmission gear.
 

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Discussion Starter · #13 ·
Does the issue ONLY occur in 4th gear at that rpm? Does it not occur in any other gear at that rpm? If is't only 4th gear then you may have a cracked tooth on a transmission gear.
I had originally thought that but paying closer attention to my rpms it's only at the 5500-6000rpm mark it starts and doesn't want to push past it. So it's just that rpm mark. Someone said maybe the cdi no rev chip malfunction?? Which the warranty covers free parts so it should be here in two weeks.. But I'm impatient and if that's not it want to know what else it could be in the meantime.
 

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Discussion Starter · #15 ·
So just to be clear, it does this in every gear?
Does it also do it in neutral?
I'll try to explain best I can, in first, no but it's a 125 so I'm shifting at 9-12mph and I'm not pushing 6k rpm. Second is difficult to tell cause right when I need to shift I'm at that rpm but I'll say yes I'll feel a slight jerk.. 3rd is definitely and 4th is 110% can hardly push 35-40mph which I've done 65 smoothly before all this. And in neutral before this happened I got alittle excited one time and reved to 12k rpm.. And I was curious the other day so I tried and it limited my rev to 8k rpms... hope that helps you help me.
 

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I understand that it does this when your riding. What I am trying to find out is if it is an engine, electrical, or drive train issue. That's why I ask simple yes/no questions. You may need to lift the bike with a jack or put it on some type of stand. But you need to determine whether it does this in ALL gears, SOME gears, or in neutral (NO gears). If the issue persists even in neutral then that would eliminate most drive train issues.
That would narrow it to engine or elec. In my experience Chinese bikes are known to use sub standard electronics among other issues.
I am also curious how you accidentally reved it to 12k rpms if it has an 8Krpm rev limiter. This leads me to think the rev limiter is defective.
 

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Discussion Starter · #17 ·
I understand that it does this when your riding. What I am trying to find out is if it is an engine, electrical, or drive train issue. That's why I ask simple yes/no questions. You may need to lift the bike with a jack or put it on some type of stand. But you need to determine whether it does this in ALL gears, SOME gears, or in neutral (NO gears). If the issue persists even in neutral then that would eliminate most drive train issues.
That would narrow it to engine or elec. In my experience Chinese bikes are known to use sub standard electronics among other issues.
I am also curious how you accidentally reved it to 12k rpms if it has an 8Krpm rev limiter. This leads me to think the rev limiter is defective.
I would say yes it's in all gears. Just 1st is so short I can't tell.. And when I first got the bike i didn't have this problem until a week ago at which I was at 297miles, is when this problem occurred. So when I first got it i was excited lol.. dropped a rev bomb to 12k rpms... But I was saying NOW, since this has been an issue I tried reving to see out of curiosity and it limited the rev to 8000rpms... So, it shouldnt have limited it in my mind.. So I also think it may be the rev limiter chip now that I've kinda laid it all out in thought in writing with you.
 

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Well you satisfied my curiosity about proper oil. Thanks. Now to the rev limit. Which does it have, a 12k or 8k limit? And is 6k all it does now period, even in neutral? I don't know anything about a Grom or Grom clone other than they are cute and look like a lot of fun. I'm not convinced it's the rev limiter but do hope it's that simple. I've just never seen one simply change where it starts limiting. If you could get 12k once in awhile I might go that route being a random failure. I know you don't have 300 miles yet but I hope it's not a dirty or failing carb. Todays fuels are worthless and fuel efficiency is high, so how long has that fuel been in that bike or did this maybe happen after a recent fill up? I'm wondering if you might be picking up water. Have you tried putting a good dose of Seafoam in it to help with water? Just a pure shot in the dark.
 

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Bad batch of gas maybe?
 

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Discussion Starter · #20 ·
Well you satisfied my curiosity about proper oil. Thanks. Now to the rev limit. Which does it have, a 12k or 8k limit? And is 6k all it does now period, even in neutral? I don't know anything about a Grom or Grom clone other than they are cute and look like a lot of fun. I'm not convinced it's the rev limiter but do hope it's that simple. I've just never seen one simply change where it starts limiting. If you could get 12k once in awhile I might go that route being a random failure. I know you don't have 300 miles yet but I hope it's not a dirty or failing carb. Todays fuels are worthless and fuel efficiency is high, so how long has that fuel been in that bike or did this maybe happen after a recent fill up? I'm wondering if you might be picking up water. Have you tried putting a good dose of Seafoam in it to help with water? Just a pure shot in the dark.
Even when I had first got it and I did the excitement rev to 12k it didn't even limit it, I just let off.. And when riding, every gear, it's 6k when the jerking happens but it doesn't even quite limit it just doesn't want to push past it without giving me whiplash and struggling extremely hard. In neutral now, it does limit it to 8k so, I can only assuming it would limit it to 8k while driving now but don't want to push the engine while driving to get to 8k to find out and risk harm to the bike or me cause it's seriously like riding a wild bull, jerking is rough. Otherwise before hand, it had no problem while driving to push past 6k and 8k rpm smoothly..

I do use the very best fuel I can get though which is 93. Have not tried seafoam but I'll give it a shot in the meantime while the cdi chip is on arrival.
 
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