NO HIGH RANGE

C

chuck hahn

New Member
Just got a old yellow 1970 CT 90. Dipped the carb in berrymans and lots of carbs spray and air. 3 kicks and it fired off. Only shifting pedal i see is the heel / toe pedal for low or high. Clicked it into low and little throttle and wheel spins. Tried the high range and nothing. Tried rolling the tire and simultaneously trying to shift into high and it wont go. Just freely spins.
So do i need to open it up and if so, what am i looking for that would prevent it going into high? Ive been thinking possible bent shifting fork???
 
And i have a second question. The frame is yellow but the gas tank is red. Is this proper or has the tank been replaced. Once i can get the high range fixed and sort everything my intention is to repaint it and if the tank is supposed to be yellow i will make it so.
 
You have a model that isn't very popular in the rebuilding dept or Lil Honda circles. I never owned one or worked on one. No response is better than the wrong response. It would help if you actually post up your findings that could help any other unfortunate ct90 owners with hi/low problems that happen along here in the future..
 
Yeah well i wont be able to get at it for a few weeks. Im new to the trans problems myself but have done top ends on CT70, CT90, and ATCs before. From looking at parts fiches on CMSNL near as i can figure take off the oval sub cover and wiggle the shifter and see what moves or at least attempts to move.
Also im thinking if i find fork is bent heat it and straighten it to test that issue is resolved THEN replace it. No need to buy the part until i know it will be needed.
 
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I just watched a video on youtube and it seems like you can take the little cover off and grab the lever and push back on the gear to put it in high. Gear pulled forward is low range. Test it after it's in high and see how it shifts.
 
Thats the kind if info i needed. This coincides with my assumptions. Based on the setup its used on tons of models and years so what fixes a 90 will most likely fix a 70
OLD CT.. Just had another thought. I have no idea how long it has sat. So im wondering if the gears are maybe a bit rusty and hanging up. Speedo shows a bit over 6,000 miles and im thinking it may be wise to replace clutch fibers too.
 
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YES! I'm thinking squirt some tacky Lucas oil stabilizer in there and work it in! Too bad we can't use Marvel Mystery in the bottom end. Not wet clutch friendly.
 
What about seafoam? Think that will loosen stuff up? And yes i agree old oil will gel up in the gears and grooves. Ive heard seafoam will dissolve gunky build up.
 
Since it runs, i think ill put seafoam in the oil and run it with a fan blowing on it for a while to just let it churn around in there. Maybe do a series of heat / cold sessions to vary the sauce swishing around. Would be so awesome if it happens to magically engage high range and do it reliably!!!
 
I would take that hi low cover off and just shoot some up there. Too much seafoam might screw up the clutch discs unless you are changing them soon.
 
Turn it off in neutral. Give the lever a firm push into high or low, it can be a bit touchy and needs to mesh in perfectly. If unsuccessful try putting into gear and move the rear wheel a bit, then back to neutral, and retry. It shouldnt be necessary to do the wheel moving thing but maybe you do have some crust. Just be firm with it.
 
Joel. Ive already tried going from low to high with it running on the center stand and i jacked the lever pretty darn hard a dozen times. Im gonna do the new clutch so its not all that much more to open up the left side and check things out. As the saying goes.. In for a penny, in for a pound.
 
The sub transmission (Hi-Low) is really easy to work on.
There are assembly diagrams available.

You can test the shifting with the cover off and watch the gears engage.
It's possible the previous owner placed the shaft with the detent grooves in backwards.This will prevent proper movement of the gear on the shift fork.
 
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