You haven't seen this one yet...another 1993 CT70
- Thread starter fatcaaat
- Start date
fatcaaat
Well-Known Member
It's a lot of work. I'll admit that the stator cover and chain guard were pretty easy. And they came out awesome. The clutch cover could probably use more attention but I'm not going to kill myself on it. These came out much nicer than I expected I'd have the patience for.A war of attrition, aren't they...especially the clutch cover? Looking good, well worth the effort. IMO the results speak for themselves.But then, I'm old-school and a big fan of polished aluminum castings
They're quality castings and I'm very happy that Honda chose to cut corners on the finishing, to satisfy the bean counters. But, that hard alloy works against you before it works for you. If one has the drive, stamina and skills, it's possible to realize a no-excuses, show quality, finish...that doesn't take much to maintain. It's the metalfinishing that becomes a mighty battle, not that the polishing is all that easy and, as you say, it's the clutch cover that test's one's...dare I say...mettle?
(sorry, it just slipped) I can take one of these stator housing/flywheel covers & chainguards from factory-painted to metalfinished & acceptably well-polished in 2-3 hours but that clutch cover will take double that. Taking it to show-quality adds another 4 hours, or so...and that's not doing much with the lower portions, that cannot be seen, on the bike.
You nailed it on the rigors. It's not easy, or fun, spending hours hunched over a buffer wheel...a situation that does not improve with age, ask me how I know. At some point, you just can't stand any more, without a substantial recovery break. That's what I call a "war of attrition".
If you have the same kind of perfectionist leanings that I do, there is another DIY option. When the clutch cover comes off, for oil spinner cleaning, take it over to the buffer for another 20-60 minute session. Over time, the finish will get better & better. For that matter, any polished aluminum part will gradually get nicer just from routine maintenance, i.e. hand-polishing with mag & aluminum polish, or NevRdull.
(sorry, it just slipped) I can take one of these stator housing/flywheel covers & chainguards from factory-painted to metalfinished & acceptably well-polished in 2-3 hours but that clutch cover will take double that. Taking it to show-quality adds another 4 hours, or so...and that's not doing much with the lower portions, that cannot be seen, on the bike. You nailed it on the rigors. It's not easy, or fun, spending hours hunched over a buffer wheel...a situation that does not improve with age, ask me how I know. At some point, you just can't stand any more, without a substantial recovery break. That's what I call a "war of attrition".
If you have the same kind of perfectionist leanings that I do, there is another DIY option. When the clutch cover comes off, for oil spinner cleaning, take it over to the buffer for another 20-60 minute session. Over time, the finish will get better & better. For that matter, any polished aluminum part will gradually get nicer just from routine maintenance, i.e. hand-polishing with mag & aluminum polish, or NevRdull.
fatcaaat
Well-Known Member
For anyone wanting to get the level of polish I got, here is how I achieved it.
1. Aircraft stripper. I got a can from Advanced auto. I had to apply, scrape, rinse, dry and repeat 3 times until all the paint was off.
2. Sand. I hand sanded any imperfections out using #400 and then sanded everything using #800, 1000, 1500 by hand. ON the stator cover and the chain guard, i didn't require any sanding at all...the castings were really smooth to start, so I just touched them with 1500.
3. Buff. I have a buffer...I used the hard wheel first and then the flap wheel. I bet for the stator cover and the chain guard, I was only on the buffer a total of an hour. For the clutch cover, I bet I was on the buffer for 60 minutes. But I am not completely happy with the clutch side (I am happy with the stator and chain guard and the cam cover)
4. Manual polish. I then used aluminum polish and rubbed each one by hand for about 15 minutes and then spent time wiping it all off
It's a time sink for sure, but a good example of what you put in you get out. I will come back and do as Racerx suggests...the clutch cover will come off for maintenance and I'll give it some attention each time. Easy enough to do while the oil is draining.
1. Aircraft stripper. I got a can from Advanced auto. I had to apply, scrape, rinse, dry and repeat 3 times until all the paint was off.
2. Sand. I hand sanded any imperfections out using #400 and then sanded everything using #800, 1000, 1500 by hand. ON the stator cover and the chain guard, i didn't require any sanding at all...the castings were really smooth to start, so I just touched them with 1500.
3. Buff. I have a buffer...I used the hard wheel first and then the flap wheel. I bet for the stator cover and the chain guard, I was only on the buffer a total of an hour. For the clutch cover, I bet I was on the buffer for 60 minutes. But I am not completely happy with the clutch side (I am happy with the stator and chain guard and the cam cover)
4. Manual polish. I then used aluminum polish and rubbed each one by hand for about 15 minutes and then spent time wiping it all off
It's a time sink for sure, but a good example of what you put in you get out. I will come back and do as Racerx suggests...the clutch cover will come off for maintenance and I'll give it some attention each time. Easy enough to do while the oil is draining.
fatcaaat
Well-Known Member
So, another bike experience of "trust" but verify. When I was working on this engine, I retained the really nice Takegawa vintage oil cooler takeoff plate because the lines were already premade and attached to a takegawa oil cooler. Swapping it from one bike to another was a no brainer...Well, after getting the bike started, it leaked and it was really tough to tell where. So I popped the plate off and looked...replaced the gasket to be sure. Still leaking. Maybe it's the top cover? Popped that off, replaced the gasket. Still leaking. Retorque...still leaking. Really boggled my mind.
Well, i decided that I was going to solve it once and for all, so I took the oil cooler takeoff plate off and gave it a really nice look over. I got a nice fresh gasket out and sized it up...BAM! Appears that this particular plate doesn't use your normal custom stock gasket...it has a custom gasket. The return line is in a different location (presumably so you have clearance) when running those large 6an lines. So, it was leaking behind the plate because there was no gasket materal there. Essentially, the return hole was only 2/3 covered.
So, i took my sheet of gasket material, traced a stock gasket, then left extra material to cover up the return hole correctly. Problem solved. Total cost materials? 2 gaskets, once small piece of gasket material, and one razor blade. Cost Time? 2 hours!!!!!! Trouble shoot with several repair trials, make the gasket, install and repair the small oil temp pickup line I tore in the process. Its a good example of how your time can add up for the most benign things.
As for running, it's not dialed in but runs OK...starts and idles well, and seems ok so far, but running terribly rich. It is jetted as it was when running the Trailbikes V2 head, so I guess I should have expected that I'd need to rejet. Once I get it rejetted sometime this coming weekend and straighten the handlebar that was bent during shipping (too tight on the tiedown), this sucker is ready.
Well, i decided that I was going to solve it once and for all, so I took the oil cooler takeoff plate off and gave it a really nice look over. I got a nice fresh gasket out and sized it up...BAM! Appears that this particular plate doesn't use your normal custom stock gasket...it has a custom gasket. The return line is in a different location (presumably so you have clearance) when running those large 6an lines. So, it was leaking behind the plate because there was no gasket materal there. Essentially, the return hole was only 2/3 covered.
So, i took my sheet of gasket material, traced a stock gasket, then left extra material to cover up the return hole correctly. Problem solved. Total cost materials? 2 gaskets, once small piece of gasket material, and one razor blade. Cost Time? 2 hours!!!!!! Trouble shoot with several repair trials, make the gasket, install and repair the small oil temp pickup line I tore in the process. Its a good example of how your time can add up for the most benign things.
As for running, it's not dialed in but runs OK...starts and idles well, and seems ok so far, but running terribly rich. It is jetted as it was when running the Trailbikes V2 head, so I guess I should have expected that I'd need to rejet. Once I get it rejetted sometime this coming weekend and straighten the handlebar that was bent during shipping (too tight on the tiedown), this sucker is ready.
I think that, at this late date, you'd agree that there's no such thing as "plug & play". Given enough time, experience & exposure, just about anything that can have an issue will leap from the shadows and bite, usually when least expected. Seems that taking anything for granted, no matter how routine is an act of faith...or stupidity (I'm not sure where that line gets drawn)...so your "trust but verify" approach is sound as bedrock.
fatcaaat
Well-Known Member
Things continue to be challenging with this bike. Tonight, I decided to get the handlebar straightened up and it didn't go as smooth as I had hoped. I ended up breaking the area of the upper clamp that holds the handlbars in, breaking a section of the V's while in the process of getting it straight. Now, while normally that might have been something that would cause lots of cursing and throwing wrenches, this turned out to be a blessing in disguise. One thing I can say is that this clamp never held the bars securely...they always had just a little bit of wobble no matter how much I torqued down on them. I believe they are actually G-craft.
Anyway, I happen to have another top tree here and I polished it all up and nice. I had to take the top clamp that the handlbar holder bolts to and mill it as the bolt spacing was slightly different by about 1/2" but isn't a big deal seeing I have a mill. I got it all back together and two things were noticed. First, the handlbars are in a better overall position using the stock clamp over the g'craft as they are a bit more forward. Secondly, the wobbly is gone...you can get them super tight. So while I needed to invest about 2 hours for this whole debacle, the result is an overall improvement and I'm quite satisfied with the result.
There are four things left...jetting, doing something with the oil vent/return open bung on the bottom, and repositioning the front fender, and reattaching the oil temp pickup again as I didn't repair it 100% previously.
Anyway, I happen to have another top tree here and I polished it all up and nice. I had to take the top clamp that the handlbar holder bolts to and mill it as the bolt spacing was slightly different by about 1/2" but isn't a big deal seeing I have a mill. I got it all back together and two things were noticed. First, the handlbars are in a better overall position using the stock clamp over the g'craft as they are a bit more forward. Secondly, the wobbly is gone...you can get them super tight. So while I needed to invest about 2 hours for this whole debacle, the result is an overall improvement and I'm quite satisfied with the result.
There are four things left...jetting, doing something with the oil vent/return open bung on the bottom, and repositioning the front fender, and reattaching the oil temp pickup again as I didn't repair it 100% previously.
Donald_50
Member
fatcaaat
Well-Known Member
Thanks. I originally sold this bike because it wasn't mine...i purchased it from someone that had it configured how they wanted it. i realized I didn't want that and I didn't keep it too long. However, after thinking about it for 3 years, I realized that it had good bones and I could make what I wanted from it so I bought it back. I have changed a lot of things on this bike, and now it feels like my bike. Here's a quick list of the items that are different from what was originally designed.
Complete engine used to be a TB117 and now its a Honda Nice 142cc, different intake manifold.
Footpeg assembly converted to rearsets and seperate kickstand setup.
Rerouted all gas lines to my specifications
Changed the levers and perches
Changed the angle of the exhaust hanger
Changed the vent system/catch can
Changed the front tire
Changed the front fender
Changed the gearing (dramatically)
Changed the angle of that handlbars by installing a different top tree
In the little bit of time I rode it, I can tell this bike is going to be awesome. Its solid and pulls really hard. brakes are probably way more than ever needed on one of these bikes. It's going to be fun messing with people on the backroads around here.
Complete engine used to be a TB117 and now its a Honda Nice 142cc, different intake manifold.
Footpeg assembly converted to rearsets and seperate kickstand setup.
Rerouted all gas lines to my specifications
Changed the levers and perches
Changed the angle of the exhaust hanger
Changed the vent system/catch can
Changed the front tire
Changed the front fender
Changed the gearing (dramatically)
Changed the angle of that handlbars by installing a different top tree
In the little bit of time I rode it, I can tell this bike is going to be awesome. Its solid and pulls really hard. brakes are probably way more than ever needed on one of these bikes. It's going to be fun messing with people on the backroads around here.
fatcaaat
Well-Known Member
I sold it, rather cheaply, to a guy that wanted a motor. I advertised it here a lot and no takers. Too bad someone from our community didn't buy it. I always see people looking to build motors or put chinese engines in their bike and this was available at a fraction of the cost it took to build it. Someone got an incredible motor for a very economical price.
Jdmonealp
Member
Mr Fatcaaat, is there a source for NICE motors these days? Ive bought 2-3 off asian concept waaaay back, but i see they have been gone awhile. (not that the engines were rebuilt that great... but it was decent, cheap, and easy to order). Thinking about setting up another mini soon and was wanting another nice, but dont want to pay a ton.
fatcaaat
Well-Known Member
I believe the only sources I know of are racerx here on the forum, and TRP and TJR out of Germany that can get you them.
fatcaaat
Well-Known Member
Here is the final result of this bike. It's done as far as I'm concerned although I guess we can always add something along the way to make it nicer.
The jetting was pretty interesting. With the TB V2 head on this engine with no other modifications to exhaust or carb the jetting was 25/200. Adding the Honda Nice stock engine, porting it, and putting a cam in it resulted in jetting at 20/180. I still have a little tiny off-throttle hesitation on this, which is a rich bog. I may try a 17.5 pilot but I am not sure I'm going to be able to remove that with the VM26 carb.
I took a few pictures out in the sun so you can see the final result. So far, I've only done about 50 miles with it or so. It has plenty of power and stops better than any other bike I own.
The jetting was pretty interesting. With the TB V2 head on this engine with no other modifications to exhaust or carb the jetting was 25/200. Adding the Honda Nice stock engine, porting it, and putting a cam in it resulted in jetting at 20/180. I still have a little tiny off-throttle hesitation on this, which is a rich bog. I may try a 17.5 pilot but I am not sure I'm going to be able to remove that with the VM26 carb.
I took a few pictures out in the sun so you can see the final result. So far, I've only done about 50 miles with it or so. It has plenty of power and stops better than any other bike I own.
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IMO, you're dealing with an inherent limitation...the stock valve size. Subtracting the area obstructed by the valve stem, there's not much more cross-sectional area possible, i.e. open to airflow, beyond the stock 22mm port diameter. Not saying that there's no potential gain lurking in this casting. I am saying that virtually all of it would come from changing the port shape. Unfortunately, there are tradeoffs; increased port volume means decreased flow velocity, along with the unknown effects on turbulence and swirl, of the incoming charge, as it enters the combustion chamber. The expected side effects would be loss of efficiency, as manifested in mpg numbers and low-rpm hiccups...like you're getting. I'll take your word for it that this is a transient rich misfire, despite the fact that it strikes me as a transient lean stumble. You're there and know your way around carburetion while I'm ~900 miles away, behind a keyboard. If you are correct, then there's a high probability that fuel is puddling in the intake, at low rpm...due to undesirable turbulence.
Speaking in theoretical terms, the ideal would be a raised intake port, with a uniform 22mm ID. That would mean welding-up the port floor by the same amount its roof is raised. With an extra 4mm of bore size and ~30% displacement increase, there should be enough vacuum to compensate for the port volume increase and likely any loss of swirl that was engineered into the port configuration...in terms of peak hp & throttle response. Unshrouding a valve is a classic method of gaining airflow (and with it, hp) what's never discussed is the bottom line impact on efficiency. The acid test...and you're the one person who could do this...would be a side-by-side comparison (literally, this bike & your stock Nice-powered bike) of fuel consumption numbers. To date, I've yet to see a big-displacement tune that didn't slurp fuel at a disproportionately high rate. (FYI, I'm talking about normal road riding, not 60mph+ sustained.) That's a textbook manifestation of reduced efficiency.
Since this is going to be a serious tourer, efficiency (fuel consumption, throttle response) and simplicity are part of the equation, imho. I'd be thinking in terms of a 22mm carb, minimal work on the intake port...with the goal being uniform, high-velocity, airflow... and the bigger port changes on the short-turn side of the exhaust port. Best, educated, guess is that this motor is ideal for a VM22, fitted with a #25 or 27.5 pilot jet and somewhere around #210 main. With this displacement & head configuration, I'm not sure that the more refined MJN22 would make much of a difference and the VM22 is dirt cheap.
FWIW...
Speaking in theoretical terms, the ideal would be a raised intake port, with a uniform 22mm ID. That would mean welding-up the port floor by the same amount its roof is raised. With an extra 4mm of bore size and ~30% displacement increase, there should be enough vacuum to compensate for the port volume increase and likely any loss of swirl that was engineered into the port configuration...in terms of peak hp & throttle response. Unshrouding a valve is a classic method of gaining airflow (and with it, hp) what's never discussed is the bottom line impact on efficiency. The acid test...and you're the one person who could do this...would be a side-by-side comparison (literally, this bike & your stock Nice-powered bike) of fuel consumption numbers. To date, I've yet to see a big-displacement tune that didn't slurp fuel at a disproportionately high rate. (FYI, I'm talking about normal road riding, not 60mph+ sustained.) That's a textbook manifestation of reduced efficiency.
Since this is going to be a serious tourer, efficiency (fuel consumption, throttle response) and simplicity are part of the equation, imho. I'd be thinking in terms of a 22mm carb, minimal work on the intake port...with the goal being uniform, high-velocity, airflow... and the bigger port changes on the short-turn side of the exhaust port. Best, educated, guess is that this motor is ideal for a VM22, fitted with a #25 or 27.5 pilot jet and somewhere around #210 main. With this displacement & head configuration, I'm not sure that the more refined MJN22 would make much of a difference and the VM22 is dirt cheap.
FWIW...
fatcaaat
Well-Known Member
Bob, I tend to agree with your assessment. I am running a VM26 since that's what I have here that came with the bike. I've been scouting around to see if I could find myself a MJN22. As for the ports, I did not hog these out..they were cleaned of casting flaws with careful work around the valve area and around the guide area, but otherwise were not really opened up. On the exhaust, I did the same thing.
Everywhere across the entire range of throttle, the VM26 seems to work quite nicely with no hiccups or odd transitions. However, just that off-throttle bog is agitating a little. With a 22.5 pilot in there, and it being 32 degrees overnight, the bike started ice cold on 1 kick without the choke. THat was pretty surprising.
I am pretty set on dropping a few $$ and adding an MJN, but I"m not sure which one. The 22 seems to be the size I want but the 24 is currently on sale super cheap at the moment. I may try popping the 22 on there from the other bike and seeing what happens.
Everywhere across the entire range of throttle, the VM26 seems to work quite nicely with no hiccups or odd transitions. However, just that off-throttle bog is agitating a little. With a 22.5 pilot in there, and it being 32 degrees overnight, the bike started ice cold on 1 kick without the choke. THat was pretty surprising.
I am pretty set on dropping a few $$ and adding an MJN, but I"m not sure which one. The 22 seems to be the size I want but the 24 is currently on sale super cheap at the moment. I may try popping the 22 on there from the other bike and seeing what happens.