Motorcycle Repair/1970 CT90

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Question
WHY DOES MY LOW RANGE GEAR KEEP POPPING OUT OF GEAR, UNDER A HEAVY LOAD? LIKE GOING UP HILLS, ETC.
BIKE WORKS FINE IN HIGH RANGE.
THANKS YOU!

Answer
Mike, the shift selection parts seemed to have had some updates. I would swear that I have seen some kind of service bulletin on the Hi-Low range components, but am not able to locate it at this time. I would buy some gaskets and seals in advance of disassembling the side case components to look at the parts involved and determine if any are damaged or worn excessively.

There are LOTS of parts on eBay for sale and numerous CT90-110 forums on Yahoo and elsewhere.

I found this, too, but it is more of a transmission bulletin that the Hi-Low range bulletin.

http://www.allworldauto.com/recalls/NHTSA_66V003000_9999_HONDA_CT90_recall_38890

http://ct90-ct110.com/PDFs/CT90_Pre-1977_Bundled_Shop_Manual_PDF.pdf  about half way down is the "Posi-Torque" Hi-Low range function mentioned, but nothing of great detail about troubleshooting it.

After digging around in my archives I did find this reference to your problem, depending upon when your bike was built....

Honda Bulletin CT90 #8   Sliding low gear part number 23932-053-010 and Spring, ball set part number 24271-053-010.  For use on bikes with frame numbers up to 179373.... If your bike is beyond that frame number, then it will already have the correct parts and there is a possibility that something is damaged inside the transfer unit.

Bill Silver  

Motorcycle Repair

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Bill Silver

Expertise

Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.

Experience

I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

Organizations
VJMC (Vintage Japanese Motorcycle Club) of North America

Publications
VJMC newsletter, as editor for two years and as contributing editor currently.

Education/Credentials
3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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