CT70HK0 Restomod - Help/Input Appreciated :)

Streak09

Streak09

Member
@kirrbby, excellent perspective and advice as usual! @racerx, you have excellent points about future costs and knowing that it was done right. I really don’t plan on letting this bike go for a while, so that plays a big impact.

I guess my hesitation is the cost. I originally set out to just get it running with maybe an 88. The. It grew and grew, you know, like a typical project lol.

That being said, I picked the bike up on the cheap 4 or 5 years back, so my entry fee there is long gone. No pain there lol. I try to stay within my means on my hobbies (key weird, TRY :LOL:). Typically try to find a way for them to fund themselves to some extent. I’ve done a decent job accomplishing that, but I am a bit short for this build. I will need to find a way to come up for the shortcomings. Challenge accepted :geek:.

So, sounds like I’m heading down the path of a 12V 108 sleeper. It’s feels right, let’s do it! :yellow70:

You guys are awesome, I know you will be of great help, you already have! (y)
 
6

69ST

Well-Known Member
Probably Lifan alternator parts. Should be fine for your purposes. Believe me, if these were failure prone we'd have heard about it by now...and Tbolt would be listing something else.

Do be sure that you choose the right crankshaft. I assume it'd be a 12vCDI type. Trailbikes does 51mm cranks in all 3 CT70 flavors.

That'll get you a (more or less) plug & play electrical system. I'd suggest contacting Tbolt, to get a matching wire harness, or pigtails for the CDI module & reg/rec, as well as the CDI module itself...all basic, off-the-shelf parts and inexpensive.

FYI CDI modules usually have spark advance programmed into them. Electronic advance is better than mechanical.
 
kirrbby

kirrbby

Well-Known Member
Tbolt is a good reputable supplier. But that is not what a average 12v stator setup looks like.
It's plenty cheap, as long as it works and lasts. I would want to know some details before you buy it. Starting with...is this for a 12v lighting system. Maybe end with...does it work well and last long. Lol
I wouldn't buy that one unless someone would vouch for it.
 
6

69ST

Well-Known Member
There's one surefire way to get OEM reliability...OEM Honda parts. Flywheels & stators can be sourced new or used. Only problem, no lighting coils. The surefire/easy solution...Ricky Stator. The cheap solution, learn how to wind the bare armature posts...more tedious than difficult. I am guessing that your lighting requirements will be pretty basic & minimal.

So, you now know three different solutions...and there are more out there.
 
Streak09

Streak09

Member
I’ve reached out to TBolt for some guidance, so hopefully I get some good feedback.

I could also use some help with sourcing a lower end. Exactly which models will work without modification with a 12V system? I know any CRF/XR 50/70 will work. But what about some of the older models? Seems like the buy in for a CRF/XR lower end is pricey. Will any ATC or TRX cases or bottom ends work? Looks like those are more reasonably priced (maybe for a reason?).
 
6

69ST

Well-Known Member
I am thoroughly unfamiliar with ATC & TRX lower ends. Some lack kickstarters and I'm not sure of that means just a different outer clutch cover or some difference(s) in the cases themselves.

I'd suggest adding-up the individual parts, then making your cost comparison.
  • 12v/CDI cases
  • Stator plate
  • Stator assembly
  • Flywheel
  • 12v style kickstarter assembly
  • Flywheel cover
  • Crank trigger/ignition sensor for the CDI
I've seen some stupid-high asking pricYou needn't mention this to a seller, of course.es for 12v lower ends...and I'd walk away from those. Consider what you actually need. Fact is, as long as the cases & alternator assembly aren't damaged, you can source an otherwise trashed engine, since you don't even want any of the top end parts, or the stock 41.4mm crank. A thrashed, non-running, engine is worth maybe $100-150, tops, without proof of what's inside being usable. That's considerably less than the total cost of the parts listed.

Another approach would be to source a combination of individual parts, both new and used.
 
Streak09

Streak09

Member
I’ve done some figuring, and i would have to find a pretty screaming deal on a complete lower end for it to make sense to go with a CRF/XR bottom (I’m talking sub $100 including flywheel/stator). I am finding most INCOMPLETE bottoms for $200+.

What I did find, though, is a CDI unit for the H models on DrATVs site. Completed with flywheel, stator, and CDI unit. That may put me back into the realm of sticking with the H cases. That and the fact that if I source other cases, I feel the need to buy a new clutch assembly and trans in order to not completely dismantle the H motor. I need to use as much as the H as I can, so it just makes sense to use it as the base.

I’ve decided I really can’t shell out the extra for AHP or other drop in transmissions. I will do shift forks though. I have to draw the line somewhere or this thing will run away from me from a cost standpoint (it’s already jogging!).
 
kirrbby

kirrbby

Well-Known Member
Atc70 engine cases are pretty much the same as ct70 cases of similar years. Atc70 engines are all 6v. 6v cases CAN be used to convert to 12v, but you have to cut a small notch out of the left side case for the trigger mount of the stator plate.
ATC70's are 3speed semi-auto's until mid 1982, they became 4down 4 speed semi-auto's. In 1985 they changed the shift pattern...4up semi-auto.
In 1986, 3 wheelers were outlawed and the TRX70 4 wheeler was born.
They were made only in 86 and 87. They are 4up semi-auto's, like the prior ATC's, BUT...the stator changed to ?, not sure what exactly...and the engine cases changed to GB4 12v type engine cases. The TRX70's are all 4speed semi-auto's in 12v cases. They have a 12v type crankshaft too.

ATC70 and TRX70 cases...and engines, can usually be had for cheap on eBay. They are a good choice to build engines for CT's and Z's.

Kickstarter's can be added, you just need to use a clutch side cover that has the kickshaft hole...or drill/mill the hole in the Atc70 side cover. Then use the correct pinion gear on the kickshaft...depending on the transmission used.
 
OLD CT

OLD CT

Well-Known Member
2 new O.E.M. shift forks are 100. A complete AHP trans w forks is 150. I dunno if there is a big savings there. I have had great luck with the AHP.
 
kirrbby

kirrbby

Well-Known Member
The only problem I have with the AHP is that it's a 1d3up shift pattern. No problem on a manual clutch, but I'd never use one for a semi-auto.

But no matter the trans, I'd hate to see someone cutting on the engine case of a matching #s bike, in order to run a CDI, when you can buy engine cases for $45.
 
Streak09

Streak09

Member
kirrbby said:
The only problem I have with the AHP is that it's a 1d3up shift pattern. No problem on a manual clutch, but I'd never use one for a semi-auto.

But no matter the trans, I'd hate to see someone cutting on the engine case of a matching #s bike, in order to run a CDI, when you can buy engine cases for $45.
Click to expand...

I get where you are coming from, but is it really impacting the value of the engine? I wouldn’t say cutting a small notch for clearance is “hacking it up” it’s still a functional H motor. I would rather see the matching H engine stay in the matching H bike. If it were a pristine, untouched engine, okay, I get that. But it’s not.

I get your point though. I’ll have to chew on that one.


OLD CT said:
2 new O.E.M. shift forks are 100. A complete AHP trans w forks is 150. I dunno if there is a big savings there. I have had great luck with the AHP.
Click to expand...

That is a very valid point. Didn’t really look at that closely. They are listed on eBay for $150, with a Best offer option. May be able to get it a bit cheaper.
 
6

69ST

Well-Known Member
There are differences of opinion when it comes to shift patterns, clutch type, and shift levers. Personally, I prefer the "international" (1d/3u) shift pattern, paired with a heel/toe shift lever. I am strictly in the manual clutch camp...personal prefetence. That said, Honda sold bikes with the "international" shift pattern in semi-auto clutch flavor...including the CT70s cousin, the ST70. Most ST70s were 1d/2u 3-speed semiauto...all had the heel/toe shifter. If semiauto is your preference, then I'd suggest using the heel/toe lever. Some riders hate them...I see the toe-only lever as cumbersome and, on the trails, downright unsafe in certain conditions.

I'd have zero compunctions about going with either 4-speed (OEM or ahp). Dunno about the quality or/and durability differences between them. I believe OE is superior but that may not matter. OE is getting more expensive. A buck-fifty is cheap for a tranny. My only reservation about ahp is that I've yet to see anyone put 5-digit mileage on one. The day I see a few 20,000 milers still healthy is the day I start giving the 2 thumbs up endorsement. It could happen...some day. So, for now, let's say no obvious problems, could prove itself, cheap, available and...you may not have 10,000+ miles in your plans, that could make a difference, too.

FYI there are CDI conversions available that don't require notching the case. Dratv may still have them.

Lotsa options...you've not exhausted every choice, yet. Take your time and you'll come up with something that checks the important boxes...
 
A

allenp42

Well-Known Member
The only CDI kits I'm aware of where you don't have to modify the left side case are these 2. Both are from Malaysia. Please note, however, that some have had issues (did not work) on a Hitachi H from xrarespares.. They both look very similar but I have no idea if they are in fact the same parts (coil, cdi module etc). It could be that one copied the other?

Note: These are both 6V so if 12v is a must have, neither will be what you need.

Pretty sure that OLDCT has the kit on K0?

Seller: ohtokc
https://www.ebay.com/itm/Honda-Z50-...663260?hash=item261d9e2f1c:g:~2YAAOSwFQhdbNbY

Seller: xrarespares
https://www.ebay.com/itm/HONDA-CT70-CT70H-Z50-ATC70-SS50-Dax-XL70-CDI-Electronic-Ignition-Free-Postage/360940998284?fits=Model:CT70|Make:Honda&hash=item5409c28e8c:g:2qUAAOxyhS9TfchT
 
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