94 CR 250 Ground Up Restoration IMS Wide Ratio Transmission Issue

M

Moto7man

Member
I have been working on this restoration for about 18 months gathering parts. I am in mid assembly and I ran into a problem with installing the IMS Wide Ratio Transmission. I have a thread on another forum and some of the GG members already know about it. I have 4 of the 5 IMS gears installed without any problems at all. (2 on the mainshaft and 3 on the countershaft). The problem is the last C3 gear on the countershaft fits perfectly but the I.D. of the gear (with the bushing) is too big for the shaft. Any suggestions would be greatly appreciated.


This is the countershaft,the bigger gear is the stock Honda gear and the other gear is the IMS gear. Note the stock Honda bushing(collar)inside the IMS gear. Between C3 and C5 it is a bushing that rides inside C3, there are also a single washer on each side of C3. There isn't a spacer. The I.D of replacement gear is 24.98. The bushing(collar) O.D is 21.99 and the Bushing(collar) I.D is 18.99.I have attached photos showing the replacement gear loosely positioned on C5 without any collar so you could see the gap between gear and countershaft. I also included photos of C3 and C5 which show witness marks that they were previously mounted together. C3 and C5 seem to fit together perfectly except for the bushing(collar).
 
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This what she looked like when I picked her up about 18 months ago.

8UYKuOLl.jpg


image_zpshextp9cn.jpeg


IMG_0391_zpsuandjiaq.jpg
 
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Does the large bore of the suspect gear fit on any other shaft steps? If it's not supposed to go somewhere else, maybe the wrong gear was put in the kit.

If all else looks correct (except for the bore), a machine shop could do up a bronze bushing to press into the gear. Aluminum bronze would be tough enough to survive.
 
Neil E. said:
Does the large bore of the suspect gear fit on any other shaft steps? If it's not supposed to go somewhere else, maybe the wrong gear was put in the kit.

If all else looks correct (except for the bore), a machine shop could do up a bronze bushing to press into the gear. Aluminum bronze would be tough enough to survive.
Click to expand...

I am having someone else who is intricately familiar with these IMS kits verify the gear was the correct one for the kit. I sent him all the dimensions today. Thanks for the aluminum bronze specification, I was vaguely thinking about someone like that but Neil I could not articulate it with your precision.THANK YOU!:D
 
If this is the wide ratio transmission you got from me then-
It is complete and a 5 gear matched set.
I bought it new and ran it in my personal bike (1987 CR 250).
I took the set out of the bike before I sent it to you.It was not a loose gear set scattered here and there.I counted all the teeth and double checked the ratios before I sent it out to you in the original box.
should fit 1986-1996 CR250 at the least.

there are some slight differences between years on shafts and stock number of teeth on some years.I think and don't quote me that there was a 12 and 13 tooth shaft available depending on years.Ive also seen differences in other years a tooth here and a tooth there.
But,make no mistake that is the original IMS wide ratio transmission set distributed by Moose racing at the time and application for 1986-1996 CR 250.

Im sorry you are running into an issue.
Look it over close,do you home work,Cross reference microfiche etc.etc.
Don't listen to some joker whos" heard about this or heard about" that.

Goodluck
 
gasgasxc said:
If this is the wide ratio transmission you got from me then-
It is complete and a 5 gear matched set.
I bought it new and ran it in my personal bike (1987 CR 250).
I took the set out of the bike before I sent it to you.It was not a loose gear set scattered here and there.I counted all the teeth and double checked the ratios before I sent it out to you in the original box.
should fit 1986-1996 CR250 at the least.

there are some slight differences between years on shafts and stock number of teeth on some years.I think and don't quote me that there was a 12 and 13 tooth shaft available depending on years.Ive also seen differences in other years a tooth here and a tooth there.
But,make no mistake that is the original IMS wide ratio transmission set distributed by Moose racing at the time and application for 1986-1996 CR 250.

Im sorry you are running into an issue.
Look it over close,do you home work,Cross reference microfiche etc.etc.
Don't listen to some joker whos" heard about this or heard about" that.

Goodluck
Click to expand...

No worries, It is the same set, we are working on it, PM sent.

Update; The original IMS instructions had a typographical error. IMS Wide Ratio Transmission is now assembled and being installed in the new engine!
 
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I am going back checking the install to see anything is incorrect.

This is how the mainshaft and countershaft were assembled. The two top bags include the two stock mainshaft gears. The three bottom bags include the three countershaft gears(the IMS gear and the stock gear are to the left of the bottom left bag, these are the ones that we are having a difficulty.)

All these bags include the removed stock Honda gears, each bag is labeled with number of teeth for the Honda gear, then , at the bottom middle of the bags you will see the label. (replacement IMS gear with the number of teeth.)

So this shows exactly which gears were removed , how many teeth they had, and how many teeth were on each IMS replacement gear that replaced them. I counted the teeth on each stock gear, then I counted the teeth on each IMS gear as I replaced them and labeled each bag. If anybody sees a problem, please let me know because I am scratching my head on this one.
 
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While I am waiting on some other detailed on the transmission, I am moving ahead with the chassis and other things. I just got some new parts.

Boyesen clutch cover


IMS 3.1 gallon tank, which is giant-enormous.



And front and rear Buchanan spokes
 
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I laced up the 18 and 21 inch rims last night. Somewhat simple, I just ordered a stand so I can true them.

Rear rim. It was cold as heck here last night, so I laced them up in the den while I watched the Grand Tour with Jeremy Clarkson, James May and Richard Hammond.
Front rim
 
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I was thinking the same thing and I am kinda on the fence right now about it. I could not find an IMS tank bigger than the stock tank without going to the 3.1.
 
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