85 250es Build Question

[ZacH_GrifF]

Im in the process of doing a complete engine rebuild on my Big Red right now and Im at the point where my two crankcase halves are together. My question is should my transmission be able to change gears by hand with no lubricant in the case or should I need two have the shifter on to change the gears. I ask this because I want to know if I put the internals together right so if I didn't i can separate it before I go to installing the clutches.

[Flyingw]

You need the right side of the motor put together in order for the tranny to operate right but to answer your question...Yes. I usually attach a long rubber band to my connecting rod to hold it up and let it move while the crank is rotating. Then, I take a 17mm socket attached to my cordless drill and turn the crank at the flywheel CCW and shift it through all the gears to ensure the tranny is shifting right and there are no binding issues but like I said, the right side of the motor needs to be assembled including the clutch cover. You can rotate it without the clutch cover but the auto-clutch mechanism is in the clutch cover so I check that as well. Also, when you are completely assembled and the motor is back in the frame, fill the crank case with oil and turn the motor with a drill for a few minutes to prime the oil pump prior to its initial startup. This ensures the oil system delivers oil to the top end prior to startup. You can leave the two oval covers off the top of the motor and you will see oil appear while turning the motor.

[Dirtcrasher]

^ Thats a great way to test it! Easier than pulling up and down on the connecting rod!! 1st gear has a thrust washer right next to it against the case; Just be sure you check and double check because I'm sure you don't want to do it again! Lots of parts in the SX and ES motors

[ZacH_GrifF]

If I didn't have the right side put together, waiting on parts, could I rotate it from the output shaft on the back of the motor?

[Flyingw]

Ya but you wont get the full effect. Its best to wait till the right side is together. As for the thrust washers, there are 3 in the tranny gear cluster you need to be concerned with.

[ZacH_GrifF]

I think i messed up with something because I cant get the shift drum to budge so to be safe im going to separate the cases and fix it and check the thrust washers to be safe.

[Flyingw]

before you rip it apart, is the tranny laying on its side or is it sitting upright? Also you should be able to turn the output shaft with your hand, does it turn? You need the tranny gear sets to but be turning to get the gears to properly mate with their partners. Now I said you need the right side assembled but if you turn the input shaft (clutch shaft) you should be able to turn the shaft and rotate the shift drum and see a differance in the side gear shaft as far as rotation speed and it should reverse when you rotate the shift drum to reverse.

[ZacH_GrifF]

The motor is sitting straight up and i tried the input shaft too the drum still wont budge. And yes the input and output both turn its just stuck in gear and cant change the gears.

[ZacH_GrifF]

Nevermind I took the plate and star looking piece on the end of the drum and put it back on after a little bit of motor oil and was able to get it back down in neutral now my question is should i have to do anything to get it into reverse while not having the reverse stop arm on.

[Flyingw]

No, don't worry about that at this stage. That arms job is to prevent the rider from shifting in to reverse while the trike is in motion. Pulling the brake handle and stopping the trike and pushing in the reverse button ensures this. Press on for sure.

[ZacH_GrifF]

Thanks for the advice guys. Now for the clutches is their any tool available to hold the centrifugal clutch still while i get proper torque since the crank has opposite threads on each end not allowing you to hold on to the flywheel bolt?

[Flyingw]

One thing I want you to check. The shfter gear on the left side sits against the shift drum. There is a small alignment pin between them. What I have seen and caught myself doing is pushing on the assembly while inserting the center bolt to lock it down,I was pushing the shift drum to the point that the shift gear is not being kept in alignment with the shift drum because the shift drum falls ever so slightly below the case bore causing the shift drum to sit on top of the small pin. Then you lock it down that way not realizing it. Very simple to do and its not obvious until you actually fire up the motor and try to shift it.

To prevent this, since the right side is open, with your finger, push on the shift drum that come through the case on the right. Push it left while you install the shift gear and center bolt. If you push to the left and hold the shift gear up to the shift drum, try turning the shift drum. I'll bet your able to turn the shift gear all the way around with little effort. No push on the shift drum on the right and see if you can turn it. When the pin sets in to the shift gear, you wont be able to turn the shift gear. Then you will completely understand what I mean.

[Flyingw]

Thanks for the advice guys. Now for the clutches is their any tool available to hold the centrifugal clutch still while i get proper torque since the crank has opposite threads on each end not allowing you to hold on to the flywheel bolt?

I use a 1/2 inch impact to take off and put on the clutch hub nuts as well as the flywheel bolt. To lock the two gears from rotating, put a penny between the gears. The penny is softer than the gears. never use a screwdriver. Remember the centrifical clutch hub nut is reverse thread.

[ZacH_GrifF]

Yea I know what your talking about I made sure of that when I was putting the assembly together. I think the only problem now with it being difficult is lack of lubricant.

[ZacH_GrifF]

So as long as I get it pretty tight with the impact there is no need to torque?