The Ultimate Honda Trailbike Tech Thread (possible NSFW)
- Thread starter semlin
- Start date
Content may include affiliate links. Please see terms for details.
Tire change time!
I had some snowy weather on Monday, so I decided to take a crack at swapping the front tire, tube, and rim strap. The old Yokohamas are the original tires, and the rubber was quite non-gummy. Not ideal for road use.
I had purchased some Michelin Gazelles 2.5 tires for the bike, since it probably would see about 90% street and only 10% unpaved.
It was about as easy as changing a tire on a mountain bike. The old tire levered off really easily with the tire irons, and I didn't even need a rim protector.
To put the new stuff on, I first put on the rim strap, then I put the tube into position inside the new tire, and started putting the tire on at the part where the valve passes through the rim. Remember to take that first nut off the valve before passing it through the hole! Fasten the nut back onto the valve before continuing to make sure the valve doesn't move around while you are working the tire on.
I actually managed to get to the 180 degree point without much trouble, but then the tire began gripping the rim and wouldn't budge, so I put some soapy water on the edge of the rim, and the tire slid onto the rim, both beads at once!
For this, I was using the flat, tapered end of the irons--this was great for stuffing the tube into the tire as I worked along. That last bit, however, went on by hand--it was that easy.
Once it was all in place, I used my bike pump to get it up to 1/3 full, then struck the tread of the tire all around with a mallet to get the tube to seat properly, with no pinches, twists, or bends. Then, I pumped it up the rest of the way.
While I had it off, I also opened up the hub, cleaned out all the caked on old grease (even at room temp, it was like candle wax!), and lubed everything up. The wheel bearings still were pretty uncooperative, so I've ordered all new bearings and will be replacing them shortly. But that's another story.
BTW, the tire irons were the Motion Pro Enduro set, from Motorcycle Superstore. They were $19.95, and worked like a charm. Since I ordered the tires at the same time from MS, the price of the total package was pretty cheap. I think it was under $70 for two tires, the irons, and shipping.
I had some snowy weather on Monday, so I decided to take a crack at swapping the front tire, tube, and rim strap. The old Yokohamas are the original tires, and the rubber was quite non-gummy. Not ideal for road use.
I had purchased some Michelin Gazelles 2.5 tires for the bike, since it probably would see about 90% street and only 10% unpaved.
It was about as easy as changing a tire on a mountain bike. The old tire levered off really easily with the tire irons, and I didn't even need a rim protector.
To put the new stuff on, I first put on the rim strap, then I put the tube into position inside the new tire, and started putting the tire on at the part where the valve passes through the rim. Remember to take that first nut off the valve before passing it through the hole! Fasten the nut back onto the valve before continuing to make sure the valve doesn't move around while you are working the tire on.
I actually managed to get to the 180 degree point without much trouble, but then the tire began gripping the rim and wouldn't budge, so I put some soapy water on the edge of the rim, and the tire slid onto the rim, both beads at once!
For this, I was using the flat, tapered end of the irons--this was great for stuffing the tube into the tire as I worked along. That last bit, however, went on by hand--it was that easy. Once it was all in place, I used my bike pump to get it up to 1/3 full, then struck the tread of the tire all around with a mallet to get the tube to seat properly, with no pinches, twists, or bends. Then, I pumped it up the rest of the way.
While I had it off, I also opened up the hub, cleaned out all the caked on old grease (even at room temp, it was like candle wax!), and lubed everything up. The wheel bearings still were pretty uncooperative, so I've ordered all new bearings and will be replacing them shortly. But that's another story.
BTW, the tire irons were the Motion Pro Enduro set, from Motorcycle Superstore. They were $19.95, and worked like a charm. Since I ordered the tires at the same time from MS, the price of the total package was pretty cheap. I think it was under $70 for two tires, the irons, and shipping.
Last edited:
1979 CT90 for $1900
Keep on gathering those vintage motorcycle parts. They seem to be Gold plated these days. The one on this link looks to be mint.
1979 Honda CT90, ultra clean!
I sold my 110 in 84 for $800.
Silly me
Keep on gathering those vintage motorcycle parts. They seem to be Gold plated these days. The one on this link looks to be mint.
1979 Honda CT90, ultra clean!
I sold my 110 in 84 for $800.
Silly me
- Thread starter
- #105
good price for fork boots
http://cgi.ebay.com/ebaymotors/Fork...301?IMSfp=TL0903011210006r2102#ht_2728wt_1143
http://cgi.ebay.com/ebaymotors/Fork...301?IMSfp=TL0903011210006r2102#ht_2728wt_1143
Last edited:
- Thread starter
- #107
update on indicators (or as honda calls them "winkers") for the ct90
the diagram below is from an s90 which shares a lot of parts with the early ct90s, including an identical front fork layout to the 1969 k1 (for 1970 k2 and later the forks are different ). i believe is the correct setup for a k1 ct90 front, and would work on the rear for any ct90 or ct200. i have never seen oem indicators on a ct90 before a k4 and they do not appear on the parts fiche but after 1966 they are all wired for them and have handlebar switches and i think they would use this s90 setup on the rear for k1 and earlier at least since the s90 dates back to the early 60s. you can buy repros of this style of indicator on ebay by searching for s90 indicators or winkers. for the rear you also need the stay part which is honda p/n 33602028670. according to the european cmnsl site the stay part is still available.
here is an auction site for the repro winkers
eBay Motors: HONDA CB100 CL100 S90 SL100 Metal Turn signal complete (item 290302287242 end time Mar-19-09 00:08:51 PDT)
the diagram below is from an s90 which shares a lot of parts with the early ct90s, including an identical front fork layout to the 1969 k1 (for 1970 k2 and later the forks are different ). i believe is the correct setup for a k1 ct90 front, and would work on the rear for any ct90 or ct200. i have never seen oem indicators on a ct90 before a k4 and they do not appear on the parts fiche but after 1966 they are all wired for them and have handlebar switches and i think they would use this s90 setup on the rear for k1 and earlier at least since the s90 dates back to the early 60s. you can buy repros of this style of indicator on ebay by searching for s90 indicators or winkers. for the rear you also need the stay part which is honda p/n 33602028670. according to the european cmnsl site the stay part is still available.
here is an auction site for the repro winkers
eBay Motors: HONDA CB100 CL100 S90 SL100 Metal Turn signal complete (item 290302287242 end time Mar-19-09 00:08:51 PDT)
Damn. That was the holy grail of manuals.
I bet if you e-mail him, he'll still send you an attachment, on the sly.
Nice rebuild writeups on this Aussie postie bike site: The Wenga Postie Bike Project -> The rebuild
Here is an easy to navigate site for purchasing fasteners singly, or in bulk. They have oxide coated steel, zinc coated, and expensive chrome coatings in metric sizes with allen heads. No stainless in metric, though. I just ordered some allen head screws to replace the mashed up phillips head ones on my clutch cover.
Carpenter Creek Inc. : Screws, Nuts, and Fasteners
Carpenter Creek Inc. : Screws, Nuts, and Fasteners
- Thread starter
- #111
ok, here is some info on the different complete engine gasket sets available for the ct90.
there appear to be two basic sets. one is made in thailand and sells for as little as $6.00. it usually has green gasket paper but has several packages. the other is made in taiwan supposedly of "japanese" material and is sold by dr atv and others for about $20. it usually has at least some black gaskets. the easiest way to tell the sets apart though is that the thai sets are missing four small copper washer/seal things and you can usually see this in the packaging if you look hard.
the short answer is that the thai set is missing 5 gaskets including the oil pump gasket, plus those 4 little copper things.
here are photos of the two sets in the packages. thailand first. taiwan/japan second.
there appear to be two basic sets. one is made in thailand and sells for as little as $6.00. it usually has green gasket paper but has several packages. the other is made in taiwan supposedly of "japanese" material and is sold by dr atv and others for about $20. it usually has at least some black gaskets. the easiest way to tell the sets apart though is that the thai sets are missing four small copper washer/seal things and you can usually see this in the packaging if you look hard.
the short answer is that the thai set is missing 5 gaskets including the oil pump gasket, plus those 4 little copper things.
here are photos of the two sets in the packages. thailand first. taiwan/japan second.
Last edited:
- Thread starter
- #112
here is the taiwanese/japanese set broken out. notice it has the 4 small copper washers and also the oil pump gasket pictured separately.
- Thread starter
- #113
now here are 3 of 4 photos of the less expensive thai set. notice it is missing several gaskets including the oil pump gasket.
- Thread starter
- #114
here is the last photo of the thai set. i don't know what the other missing gaskets and seals do yet because i am about to order them but it seems prudent to get the more expensive set.
- Thread starter
- #115
and now for the oil seals. there are two kits again. one has 4 seals, and one has 5 
the 4 seal set is as little half the price of the 5 seal set and you can see here that it is the biggest seal that is missing.
the kit of 5 has the following
13225 POINTS ASSEMBLY SPINDLE
11.62410 SHIFTER FORK
31438 SPROCKET DRIVESHAFT
14267 RIGHT CRANKCASE
20347 MAIN COUNTERSHAFT
those numbers are actually the seal dimensions not a part number. looking closely at the set of 4 you can see the same numbers are printed on the package. the missing seal is the "sprocket driveshaft"
the 4 seal set is as little half the price of the 5 seal set and you can see here that it is the biggest seal that is missing.the kit of 5 has the following
13225 POINTS ASSEMBLY SPINDLE
11.62410 SHIFTER FORK
31438 SPROCKET DRIVESHAFT
14267 RIGHT CRANKCASE
20347 MAIN COUNTERSHAFT
those numbers are actually the seal dimensions not a part number. looking closely at the set of 4 you can see the same numbers are printed on the package. the missing seal is the "sprocket driveshaft"
- Thread starter
- #116
and the missing seal is honda part 91202-459-771 and goes on the subtransmission sprocket output
http://www.cmsnl.com/products/oil-seal-31x43x8_91202459771/
http://www.cmsnl.com/products/oil-seal-31x43x8_91202459771/
Stainless metric socket cap screws, available here a la carte:
http://shopping.barnhillbolt.com/index.asp?file=METRIC.htm
http://shopping.barnhillbolt.com/index.asp?file=METRIC.htm
On the rear fender of my CT 90, there appears to be captured nut or nut plates to accept this kind of rear setup.update on indicators (or as honda calls them "winkers") for the ct90
the diagram below is from an s90 which shares a lot of parts with the early ct90s, including an identical front fork layout to the 1969 k1 (for 1970 k2 and later the forks are different ). i believe is the correct setup for a k1 ct90 front, and would work on the rear for any ct90 or ct200. i have never seen oem indicators on a ct90 before a k4 and they do not appear on the parts fiche but after 1966 they are all wired for them and have handlebar switches and i think they would use this s90 setup on the rear for k1 and earlier at least since the s90 dates back to the early 60s. you can buy repros of this style of indicator on ebay by searching for s90 indicators or winkers. for the rear you also need the stay part which is honda p/n 33602028670. according to the european cmnsl site the stay part is still available.
here is an auction site for the repro winkers
eBay Motors: HONDA CB100 CL100 S90 SL100 Metal Turn signal complete (item 290302287242 end time Mar-19-09 00:08:51 PDT)
