Author Topic: kap384's CT70K1 Resurrection - Bonneville Pit Bikes  (Read 2000 times)

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Offline kap384

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kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« on: February 17, 2015, 04:04:43 pm »
So, a bit of a story to begin with.  This started mid-2013.  A group of us had plans to return to the Bonneville salt flats in 2014 as spectators for Speed Week, but after a previous experience in the heat, decided we needed pit bikes.  Uncharacteristically for me, I didn't do any research into an appropriate pit bike.  It was summer 2013.  A 1974 MT125 pops up, a model I was unfamiliar with.  Didn't realize Honda had jumped back into 2 strokes that early, so I grabbed it.  Unfortunately, it was too big. (Did I mention we'll need to fit at least 4 of these in the back of a pick-up?).  It was now close to Christmas, some alcohol may have been involved, and I jumped at a mint 1975 MR50 in the local classifieds.  I had never heard of the little dirt bike, but it was awesome!  It came home in the back seat of my truck the next day (PO insisted it stay inside out of the elements).  Problem was, not only was it too small, but it was way too minty to take on the corrosive salt flats.

So finally I do some research and realize that a CT70 or CT/ST90 would be perfect.


Low and behold I'm online when a CT70 pops up 10 min from my house.  Not running, but the price was right at $150.  Sold.


Ct70">


This picture is from when I'm trying to get it running.  It did come with a seat (with a completely rusted pan) but the rest was as you see it.  Tires were shot, the wrong size(in the back) with slow leaks.  Handlebars are bent in.  All street worthy wiring was cut off at the most inconvenient places.  Tail light gone, speedo gone and very low compression.


PO thought the stator was shot (didn't really think that was the case, but oh well) So $50 later I had a new cylinder, piston and rings.  Actually kept the old piston as it was domed, just re-ringed it and ran the new cylinder.  Cleaned the rust and sludge out of the gas tank and carb, new plug, new repro wiring harness, new battery and properly adjusted the points and she finally started.  New chain and sprockets were in order too.  Based on the low compression and the most worn sprocket I've ever seen, this little 70 has done some miles! 


I didn't have time to get new gaskets and o-rings for the carb before the Bonneville trip, so it wasn't the best.  New tires didn't arrive in time either.




DSC_4794">


So this is what it looked like after the salt flats.  For those that didn't know,  SpeedWeek was rained out last year, but not until after we got there.  We spent 2 days on the salt with our pit bikes anyway, having a blast.  Probably the only ones smiling at Bonneville last year.


Ct70 post salt flats wash">


Here she is after a well deserved wash. 


So the plan isn't a resto, as she'll be going back to the salt.  Just a reliable runner with parts that work, retaining the original patina.  So far a better seat and seat pan(one that doesn't threaten to give me tetanus)has been installed along with some much straighter bars.  New tire on the front (splitting the rims was fun) and waiting to do the rear.  I was able to redo the internal wiring for the horn and the Hi/Lo beam between the 2 sets of bars.  A new rectifier is in and I just ordered the rest of the bits from CHP.  Mostly just some more fasteners, new rubbers for the air box and a new exhaust as mine has more holes in it than you can count.
« Last Edit: April 07, 2015, 01:27:56 pm by kap384 »
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

Offline kap384

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Re: kap384's CT70K1 Resurrection - but still keeping it crusty
« Reply #1 on: February 17, 2015, 04:33:09 pm »
Aforementioned first purchase - 1974 MT125


Untitled">


Yes, its got the wrong tank.  Also a keen eye will notice that the oil injection system and all lighting have been stripped.  Upon further inspection though, I notice most things were done quite thoughtfully (short of the hack job on the wiring).  There are nice machined block off plates and plugs for the oiling system,  a fabricated metal inner fender to take the place of the oil tank, and a nice small Honda dirt bike flush tail light out back.  Makes me think its what someone would do to turn this enduro into a full on dirt bike back in the day.  So I'm keeping it.  Only things I'm addressing are the wiring (I'll properly rewire it to have a battery-less headlight and tail light), putting a seat cover on and replacing the side panel.  It'll also has the proper tank now, though I need to de-rust it.  Oh yeah, I also had to do something with the exhaust. It was full of holes with all baffling removed, so this little 2 stroke was about as annoying as they come.  Well, a used pipe in decent shape was going for more than $200 usually. 


Sure enough, for around $300, this NOS Hooker header came up on eBay.  Seemed like a no brainer.


">


« Last Edit: February 18, 2015, 09:59:00 am by kap384 »
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

Offline kap384

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Re: kap384's CT70K1 Resurrection - but still keeping it crusty
« Reply #2 on: February 17, 2015, 04:36:26 pm »
And the other misguided purchase, the MR50


">


Back seat of my truck on the way home


MR50">
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

Offline kap384

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  • Posts: 463
Re: kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« Reply #3 on: February 21, 2015, 12:02:46 am »
No love for a CT70?
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

Offline grcamna2

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  • I love to restore & travel. Keep'em Going Strong !
Re: kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« Reply #4 on: February 24, 2015, 08:18:18 am »
Nice small Honda's kap  8)
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S',1982' Suz. GS450TXZ
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline kap384

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Re: kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« Reply #5 on: February 24, 2015, 09:24:44 am »
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

Offline RAF122S

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  • SOHC 4 member # 2605
Re: kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« Reply #6 on: October 17, 2017, 02:10:14 am »
You realize you change in piston was likely for the late bikes, in the case of the C70 it would correlate to 83-84 and when they switched to diff cylinder and flat top piston  & long rod as well as transitioned to 12v.  So, your piston ended up in the cylinder lower than before.  Ibuyisell on ebay sells stuff for both early domed and the flat top as well as does beatrice cycle, aka dratv.

A good coat of wax or boeshield on some stuff could be good preventive... I would be tempted to flush the chassis well and maybe give it a rust eating chemical dose inside chassis and follow up with a good spray of used motor oil.  Canadians would oil spray their cars' undersides years ago, not sure if they still can. It would really lessen the corrosion but made a drippy mess until dried/dripped off or got some dust mixed in.  Might help the chassis on the CT withstand the abuse much better.

If you are still going to the salt and have and use the little ct70 on the salt. I know, very old thread.
David stuck in the curvy back roads of "Upper East" TN

Offline kap384

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Re: kap384's CT70K1 Resurrection - Bonneville Pit Bikes
« Reply #7 on: October 17, 2017, 02:31:56 pm »
You realize you change in piston was likely for the late bikes, in the case of the C70 it would correlate to 83-84 and when they switched to diff cylinder and flat top piston  & long rod as well as transitioned to 12v.  So, your piston ended up in the cylinder lower than before.  Ibuyisell on ebay sells stuff for both early domed and the flat top as well as does beatrice cycle, aka dratv.

A good coat of wax or boeshield on some stuff could be good preventive... I would be tempted to flush the chassis well and maybe give it a rust eating chemical dose inside chassis and follow up with a good spray of used motor oil.  Canadians would oil spray their cars' undersides years ago, not sure if they still can. It would really lessen the corrosion but made a drippy mess until dried/dripped off or got some dust mixed in.  Might help the chassis on the CT withstand the abuse much better.

If you are still going to the salt and have and use the little ct70 on the salt. I know, very old thread.


Thanks for the heads up on both fronts.  Haven't been back to the salt since, but did hit it with brushes and more elbow grease and no more corrosion has taken place.
1965 Honda CB450K0
1972 Honda CT70K1
1974 Honda MT125
1975 Honda MR50
1975 Honda CB400F Supersport
1977 Honda CB750F2 Supersport
1979 Honda CBX Supersport
1983 Honda CX650T
1995 Honda VFR750
2016 Honda CRF1000L Africa Twin
2015 KTM 200 XC-W
1963 Suzuki T10
My 1977 CB750F restoration - http://forums.sohc4.net/index.php?topic=66779.0
My 1975 CB400F restoration -
http://forums.sohc4.net/index.php?topic=145196.msg1651779#msg1651779
'More Stock Than Not' thread - http://forums.sohc4.net/index.php?topic=90807.500
My CT70 Resurrection - http://forums.sohc4.net/index.php?topic=145221.0

 

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