[skinnnybiker]

Hello. I have a problem with my 636. In 1st gear and 2nd when i hit right about 4k to 5k rpm the bike starts to bump for a few times, like there is no fuel or no air or idk how to explain, it just trying to push me forword then back, like its choking...the after it passes that rpm everything goes normal...what can it be?
I have cleaned the fuel pump, i have cleaned the air filter, the clutch works fine its switches to all gears, everything seems fine.
It has a power commander 3 on it (i bought it with it on).
Can u help me? Thanks and ride safe

 

[92Ninjas]

Hello. I have a problem with my 636. In 1st gear and 2nd when i hit right about 4k to 5k rpm the bike starts to bump for a few times, like there is no fuel or no air or idk how to explain, it just trying to push me forword then back, like its choking...the after it passes that rpm everything goes normal...what can it be?
I have cleaned the fuel pump, i have cleaned the air filter, the clutch works fine its switches to all gears, everything seems fine.
It has a power commander 3 on it (i bought it with it on).
Can u help me? Thanks and ride safe

I had a similar issue with the PC3 and a map that was downloaded from DJ website. At about 9k-10k RPM, I would experience a power loss. If I backed off the throttle just a little bit, it would recover. So, I did the right thing and uninstalled/removed the PC3. Going to send my ECU off for a flash instead. In the meantime, no power loss at WOT 9k-10k RPM.

 

[skinnnybiker]

I had a similar issue with the PC3 and a map that was downloaded from DJ website. At about 9k-10k RPM, I would experience a power loss. If I backed off the throttle just a little bit, it would recover. So, I did the right thing and uninstalled/removed the PC3. Going to send my ECU off for a flash instead. In the meantime, no power loss at WOT 9k-10k RPM.

I had a feeling it might be from the PC, ill try to see if i can remove it when i have time and come with a feedback. Thank you!

 

[skinnnybiker]

I took the PC 3 out and the problem is still there, i still get the power loss, any other things i should check, anyone knows?

 

[92Ninjas]

Check spark plugs and coils.
Also, does this happen in every gear between 4-5k RPM or just 1st & 2nd?

 

[skinnnybiker]

Check spark plugs and coils.
Also, does this happen in every gear between 4-5k RPM or just 1st & 2nd?

Yes, it happens only in 1st and 2nd when i throttle fast, if i pull it slow it works fine. Il change the spark plugs and air filter these days and see how it works, thanks and see you next time haha😁

 

[92Ninjas]

Now I'm starting to think it's either fuel injector related or coil/spark plug related. It's either not getting enough of fuel/air/spark or too much fuel/air.

 

[skinnnybiker]

Now I'm starting to think it's either fuel injector related or coil/spark plug related. It's either not getting enough of fuel/air/spark or too much fuel/air.

Yes i think the same, not getting enaugh fuel/air when i revv it fast, thats the only thing that could happen i guess

 

[skinnnybiker]

Now I'm starting to think it's either fuel injector related or coil/spark plug related. It's either not getting enough of fuel/air/spark or too much fuel/air.

Ok so brand new air filter and sparks and still does it. I searched more and i might be toast. I thinks its the forks on transmission. So thats like very bad...

 

[92Ninjas]

Ok so brand new air filter and sparks and still does it. I searched more and i might be toast. I thinks its the forks on transmission. So thats like very bad...

One more test... On your next test ride, keep pressure on the shift lever while in 1st gear and give it the beans (throttle. try to replicate your problem). Does it still do it? Also, try to pay attention for feedback from the lever while you're applying pressure. If it's trying to come out of gear, you should feel it.

 

[skinnnybiker]

One more test... On your next test ride, keep pressure on the shift lever while in 1st gear and give it the beans (throttle. try to replicate your problem). Does it still do it? Also, try to pay attention for feedback from the lever while you're applying pressure. If it's trying to come out of gear, you should feel it.

Ok, i took it for a ride, pull the clutch 1/2 and rev it like a mf...the gear box almost broke, it sounded like the gear tryna come out but didnt.. its very bad.. ill try to inspect the clutch plates next but im afraid it wont help, the transmission is toast.

 

[92Ninjas]

Ok, i took it for a ride, pull the clutch 1/2 and rev it like a mf...the gear box almost broke, it sounded like the gear tryna come out but didnt.. its very bad.. ill try to inspect the clutch plates next but im afraid it wont help, the transmission is toast.

Here's my take on it (Either way, the case will have to be split to repair it):

If it is your shift forks, cases have to be split to replace them. If your shifts are more clunky than normal, definitely shift forks.

I think the dogs on the gears are worn and are allowing for too much play under load. They would need to be replaced. I have heard of some people machining (undercutting more) the dogs and that solved their problem. But, with the gear coming out of second under load, replacing it is the best course of action.

Both scenarios suck because it's an engine out and case splitting repair. Depending on how much it is to repair, it might be cheaper to swap the engine out and sell yours as-is to re-coup some of the cost. Unless, you're going to service the transmission yourself (which would be the cheapest option).

 

[skinnnybiker]

Here's my take on it (Either way, the case will have to be split to repair it):

If it is your shift forks, cases have to be split to replace them. If your shifts are more clunky than normal, definitely shift forks.

I think the dogs on the gears are worn and are allowing for too much play under load. They would need to be replaced. I have heard of some people machining (undercutting more) the dogs and that solved their problem. But, with the gear coming out of second under load, replacing it is the best course of action.

Both scenarios suck because it's an engine out and case splitting repair. Depending on how much it is to repair, it might be cheaper to swap the engine out and sell yours as-is to re-coup some of the cost. Unless, you're going to service the transmission yourself (which would be the cheapest option).

Yeah bro, kinda sucks, ill see what i do, thanks for the info. Will come back to tell u what happend to the bike when time comes. Peace.