We are finding the same problem, to me it seems RPM related, if the rpm is to high when you do the shift it neutralizes, i fiddled with different RPM shifting on saturady and found that the lower the RPM is the better the shift is.



Will be interesting to see what the others have come up with.

 

Mine started that last night, I'm going to cut the shift star to increase the goove depth. I remember the pics of the modified star but haven't been able to find it yet.

 

It seems to be somewhat common on the import bikes. Some SDG's have the same problem. It's kinda the luck of the draw with the shift stars, some work and some don't I don't think that the quality control is very good while manufacturing them. Haven't found any pics online so, I just cut the groove from 2nd to neutral a lil' deeper so that the detent would sit nicely. I also cleaned up the other grooves cause I already had it out. SDG also recommended that you duble up on the detent spring to assist with the shift problem.

808SDG

 

I'm having the same problem on my kids SSR. Anyone have pics of the star and spring? WTF am I looking for?



Thanks in advance.

 

I found the post but the pics don't appear.

 

Since I'm going to have to tear into mine, should I install a 4-up shifter? Pro's/con's? Where can I get it from?





Thanks...

 

www.dratv.com

 

There was also something Posted that a stronger Detent lever Shift spring be used to help out also? and there was also some mention of a thin plate to put under or over the shift star to help keep the Detent lever in place. Well we have 1 week to fix it before a big race in Maine this comming weekend



We went racing on sunday and Matts brand new Sikk Mx with the Lifan 120cc started to jump out of gear.....Sad thing is its only got 2 hours on it if that?

 

Did a little search on RC Motors...Which their Bike the 125sx has the Lifan 120cc Motor Here was some of the Fixes for the bike. Half way down there is something to check for Under you clutch cover:





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Wow this is great I like this kind of criticism it only motivates us to improve our products.



Here are some answers to the most asked questions











Shifting well that is pretty normal for a lot of import motors but we do have a sulution it is something that can be checked quite easy just pull your clutch cover off and check if there is a little round plate behind your shift star if not that is your problem. I don't know why but some of the motors did not have them. this has been adressed to the factory. give us a call I can give you more info on this since it would take some time to explain it on here and I'm still not sure if some would get it.





Motor feeling sluggish well that has to do with long travel suspension I’m sure some of you know that with the plush suspension systems they soak up a little power on the bottom end. Next our bike is geared a little higher than others. Next our swing arm is long if we had a little conventional swing arm our bike would be a wheelie king but as you can see we built it for racing we have seen our bike beat other bikes (imports) the ones that everybody says are so fast even in our stock form our bike can be ridden faster actually I watched one of our stock bike at the MX4SX race at Competitive edge this weekend spank one of the bikes you talk about most on here so it all depends on what you use the bike for. Plus our new 24mm carb makes a huge difference









If you have more questions please feel free to ask but please know I’m not on here monitoring this site that often so its best to call us.

 

A little round plate?

Does he mean a glorified washer between the engine and the shifter on that shaft?

Cole

 

The RC Motors machines are Zongy powered, not Lifan, but I believe they share similar issues. : )

 

A little round plate?

Does he mean a glorified washer between the engine and the shifter on that shaft?

Cole

No, I believe it would be a stamped steel plate quite similar to part #9 in the diagram below, from a 1984 ATC70.

 

Well I dont know...? your guess is as good as mine all these import motors have had this issue for a couple of years now....It would be first on my list to correct dont you think?





Thought the Rc motor was a Lifan...My Bad

 

Thought the Rc motor was a Lifan...My Bad

Heh, so did I. I went so far as to shove my foot in my mouth and pm minicrosser asking about their experience with Lifan motors in their RC bikes... whoops! : )



He corrected me.



I'll be putting the Pro Mini and it's Lifan 120 on the track for the first time today, we'll see how it does. After that it'll be in the shop so I can play dress up with it, I'll pop the clutch cover off and see if the detent backing plate is present.

 

I had that same issue and the addition of the backing plate didn't change a thing.

 

yea my pro mini has done it since day one.

 

So do all of these engines do it? I mean, it seems like it would be a larger issue if they all did. I have one with 2-3 hours on it and havent noticed anything yet? Not to say I will, dont want to Jynx myself!

Cole

 

Ok not good I know the Dealer he bought the Bike from will take care of it this time but what is needed to be done to fix or help this problem? Matt says " When the tranny is in 4th gear it down shifts on its own to 3rd...

 

Mine never shift on its own. It is only when i down shift form 3rd to 2nd it hits neutral. it happens almost every time goin fast or slow. Im goin to tear it apart and see whats up.

 

Yep, that's what ours does. 3rd down to 2nd = neutral.

 

This has been an issue with all import motors no matter what the manufacture.



I hope I can shed some light on these shifting woes.



One thing ALL yes ALL the import motors have had a false neutral issues and there are several different reasons for this.



What we have found is the shift stars have poor tolerances in there design and the grooves are not made with very close tolerances nor is the manufacturing process consistent in there production. Though this problem does exist a stronger detent arm spring can fix this due to the increased pressure that is applied to hold the detent arm & roller in place on the groove of the star. There are stronger springs out there and we are going to be testing several different Honda style springs to see if they will help solve this issue. Note we have tried the all up shift drum conversion kits and they do solve the false neutral issue some what but not completely and when we do use the kit we do not use the detent spring because it is weaker than the stock one or the arm included in the kit because of clearage issues. You can modify the grooves on the star but you must know what you are doing or you will make your problem worse. You might say well if I make the grooves deeper then that should fix the problem well that can cause a whole new set of issues if you make the grooves too deep you will never find neutral (which does not really matter in a start in any gear bike but it does suck to push it up into your truck lol) another thing that will happen is your shifting will become very notchy which will make you shift harder which will bend and destroy your shift forks then you will have the tranny problem which I like to call falling into space when you get that motor that drops into neutral with out any notice while your going up the face of a jump. It also will bind up your gears and will cause your tranny to lock up and not shift at all because your tranny is literally stuck between gears. This problem will require a whole new complete shift fork & drum assembly to fix this and you could require a new tranny too.



So to solve this issue on any import you must check the following parts.



Check the shift star and make sure the detent arm roller is proper matched to the star. Then check the star backing plate (yes it is the one on the micro phish picture) this plate keeps the shift arm from knocking off the detent arm/roller off the star (this can happen when you have any impact to the shift lever which will push the complete assembly over towards the right side and cause this problem) what you will see is the end of the shift drum then some pins (these are what the shift arm contacts to turn the shift drum from gear to gear) next you will have the plate then the shift star. Next check the strength of the spring this of coarse can not done by looking at it so you will have to test different springs to find a stronger one. We will be testing the ATV springs like a ATC 110 to see if it will help we have also told the factory (we now have Lifan motors in our bikes) to assist us in this so hopefully we will have the fix for all the import bikes soon.



I have some stars coming they are much better than the stock ones they are water jet cut and should work great I also have the backing plates so if you guys need help let me know.







I hope this helps you guys I know we can solve this for all import engines it just takes a little R&D and some patience.

 

Why isn't the old Ct-70 or sl70 4speed trannys availible they are Basicly bullit proof why can't this be offered in a Drop in set-up?

 

Oldschool,



I don't think the Import engines use the same size trans shaft end bearings as the Honda engines do. I believe the Import bearings have a much smaller inner diameter (I.D.), and it would require machining down the Honda trans shaft ends to fit the smaller bearings. If I'm incorrect on this, someone will speak up and clarify it.

 

Im sure they are different what im saying is why dont the Chinese copy the tranny they copy everything else....

 

Some of the import motors use smaller shafts, some don't, only way to tell is split the cases. Dr ATV for example sells Lifan 120 case halves with both the smaller and larger shaft size bearings.



Weather or not they match the old CT bits, I have no idea.



Skin: If you get a shift improvement kit put together for the Lifan 120s, let me know. I'd be happy to test, and if you've got enough testing, well, I still want it. : )