Planet Minis

3cyltrbo

Hey guys,

Is it possible to convert this engine/transmission from automatic (all 4 down) , to manual clutch? = what is involved and where should I get it?, and for how much?

Is it possible to convert it to manual clutch with 1 down and 3 up? = what is involved – where should I get it and for how much?

I’ve swapped the front sprocket from a 14t to a 15t and finally an 18tooth. (the 18tooth is going to require a tiny bit of filing on the block because it just barely barely barely barely rubs on the block) . I swapped the rear sprocket from a 43? To a 35 or 38(don’t remember). So far I’ve gained top speed but I want some more and the engine seems like it would pull a smaller sprocket in the rear, where can I find a CT-70 rear sprocket in 32t or lower?.

I’m trying to get as much top end out of it as possible.

Lastly, I want to change the carb for anything bigger, I think its 15mm right now? (looks TINY TINY), anyone tried the Ebay 18mm and 22mm carbs?, would 24mm drown the engine?

This is the engine, it’s a 90. (Lifan maybe?)

Cheers

Will

fatcaaat

Manual clutch is easy...Buy a honda trailbikes clutch kit and swap it in. NO issues with that. As for changing shift patterns, that's much more involved and probably not worth it on this particular motor.

As for gearing....well, for a 90cc motor I'd suggest gearing 16/35...it won't pull much more than that.

firepower354

Splitting the cases to swap, like the 'caat said, is a PITA. For about what you'll have in a manual clutch kit, carb, and a big bore, you can have a new 140cc manual 4-speed that will pull that gear.

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fatcaaat

Yep...talk with Terry about a complete motor swap...You could probably sell your current setup on ebay for about 100-150 and use the proceeds to put a 140 in. I think 140's are pretty cheap these days. And...then you don't gear 16/35 You gear 17/33 and top out in the high 60's.

3cyltrbo

I was hoping to keep the motor that came in it, it seems to rev pretty high, although I do like the idea of something with more torque (ie bigger displacement).

Right now its already 18 in the front and I think its 35 in the rear (I forget)

I think with exhaust and a bigger carb and a smaller sprocket in the rear (32?) I could run in the high 40's / low 50's ?

what do you guys think about the $25 carbs on e-bay? (18mm - 24mm)???

fatcaaat

I think you are overgeared right now. That motor has enough power to reach about 45 as a stocker and maybe a max of 50mph. I think it would actually go faster if you put a 16t sprocket on the front because it won't pull that 18t to redline in top gear.

firepower354

Honda50.com Gear Ratio - Speed Calculator

Yup. You'd do 75 at 10K with the gearing you have, if you made triple the power



BTW, location?

__________________
If it has my name on it I did it;)

FirepowerMinis.com
Custom FPM parts and engines.
Parts and service for all makes.
Honda Trail Bikes parts and accessories.
Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

3cyltrbo

only 45mph? , I guess I'll have to get someone to pace me in a car because I have no speedo on it

Or strap a GPS on it somewhere?

Except for some funky tuning of the carb (dead spots in power ) it feels like it would pull the higher gear to redline?

I'm in Ottawa, Ontario, Canada (the capital) and I think we're almost at sea level - or not far off.

I'm only 160lbs and 5'9" - so there isn't alot of resistance on the bike caused by me.

I'd be super happy with 50 - 55mph that could be somewhat sustained.

Ideally I would be able to take it on most 2 lane secondary roads that have speed limits of 50mph and if I slowed down a bit going up any hills on those roads I wouldn't mind.

W

fatcaaat

I think you are going to be disappointed. That 90cc motor won't sustain 55mph no matter how you gear it. A comfortable 55mph is attained at about 11hp and will go uphill at that speed when you hit 17hp. You are sporting about 6max hp right now.

50-50

I think you're expecting too much out of a low performance 90cc engine.

You're going to either have to get a new engine or get a big bore and/or stroker kit, if those options are available for this engine, to get the performance you desire.

Don't fool around with those cheap, Chinese carburetors on eBay. If there's one place you don't want to skimp on it's the carburetor. Tuning a junk carburetor can be a nightmare and sometimes you'll never get it right.

OFFTOPIC: In regards to your username, what do you have that is a turboed 3 cylinder?

3cyltrbo

Bummer

I guess it feels so much faster when I'm bombing around my neighbourhood amongst parked cars etc… - feels like I'm going at least in the 40's ( I now realize I'm probably not), hence why I thought that 50 would be possible with some tweaks.



It seems like it runs strong enough.

As for tuning / bore kits / stroker cranks etc…., I agree with some of the other guys and I would swap another chinese motor (125cc - 160cc) before I would put too much money into this one.

OFFTOPIC = The username 3cyltrbo comes from my 1990 Chevrolet Turbo Sprint (basically the same platform as the Geo Metro/Suzuki Swift only very very different in a lot of ways). It was only offered in Canada (The United States got the Crappy Geo Metro only) and it was basically just a Suzuki Swift GTI but with a 1.0 3cyl engine (turboed and intercooled) / Swift Gti interior and exterior, mid wing on hatch etc…..etc……

My dad bought it brand new in 1990 as a toy, and gave it to me for my first car when I graduated HighSchool in 1993. I've Autocrossed it / done lapping days with it / car shows with it / 1/4mi'd it (low 15's btw) and I competed on the IASCA circuit (International AutoSound Challenge Association) in the Novice and Amateur class 1-150watts from 1994-1997 before retiring from competing to become an IASCA Judge. (Ranked 8th in the world in my class in 1995)

Its been in my possession ever since and I just took it out of a 3 year hibernation with plans to fix some age related issues and start driving it again in 2010.

Its called Jellybean (because of color and shape) its known to all my family and friends / its been in several of their weddings etc…. It’s a fixture in my family.

1996 ish



1996 ish



2001 (with my Civic at the Time)



2001 (with my Civic at the Time)



2001 (with my Civic at the Time)



First Generation of the System I competed with (circa 1994 / 95?)



Engine at 100,000km (1997)



Tried Different wheels for a while (1998?)



Being RTA'd at an IASCA show in NY city



Being Judged at the same show



At a Rinky Dink local car show (1995?)

mexicanyella

Also off topic, and sorry for the detour, but I'm getting hit with a crippling blast of auto-nostalgia here. We 'muricans had turbo sprints too. I know, because I bought a new '87 Sprint and part of my test-driving involved driving the turbo, which was in stock at at least the three dealers I visited in the St. Louis area, and deciding I couldn't afford the payments at the time. Every one I saw around here was red, but I think the brochure showed a white one too. I ended up with a plain-jane blue '87 two-door hatch, which served me well for almost 10 years and almost 200K.

I think the non-turbo Sprint may have been the last car offered in the US with a carburetor. Not sure about that.

The turbo was a hoot to drive, though. You knew when the boost came on, especially if the front wheels weren't pointing straight. It had a funny little intercooler inlet on the very front edge of the hood, almost like a handle for lifting the hood up. Offset to one side.

The more I look at your bike the more I dig the all-green frame/fenders thing. It looks kind of like the "sprout green" color the QA 50s were available in.

Wait, hold on, your car is the same body style sold as a Geo Metro here. I think the last Sprints here were '88, or '89, before the more rounded Metro nose and hood and full-width taillights appeared. Also the switch from Sprint to Metro involved going from a carbureted SOHC motor with rocker shafts and canted valves to the Metro inline valves, with presumably a wedge combustion chamber under there. I can't remember if the turbo sprints I drove had the stamped valvecover sprint-style head (looked like a Suzuki Samurai head minus one cylinder) or if they were like yours. My girlfriend back then had a Metro convertible and her car's motor looked like yours without the turbo and with throttle-body fuel injection instead of multiport. Interesting how things are different in two adjacent countries like that.

3cyltrbo

Yes, Team America did get the 87-88 Turbo Sprint (the square body style).

Its totally different from mine

-it had solid rear axle instead of independent
-it had sequential fuel injection instead of Multiport
-it had different turbo / different head / different intake etc……..

Etc…...

I think it was a ford product Fiesta / Festiva / Mercutry Tracer etc… made until mid 90's


You hit the nail on the head!!!, the first gen had crazy power delivery (like a 2 stroke MX bike). My body style has a lot smoother power delivery because it’s a different turbo / multiport fuel injection / etc….... As fun as you found that one to drive, imagine another 35-40hp (what I figure mine has gained with what I've done) (keeping in mind it weighs 1600lbs and has total hp of maybe 110 lol)

Yes the Geo Metro convertible had the same platform / some common interior pieces and more or less the same engine (except for rods / crank / pistons / valves / intake / turbo / etc….)

Yes the 89 -91 Geo Metro had the same shape as my car but it had a welfare interior - none of the performance stuff (springs / struts / anti-roll bars / engine etc……..) different bumpers - recessed lights etc…..

This is the Turbo Sprint you're talking about





Here is the two generations side by side



As for the CT 70

I know my original questions had to do with with sprockets and stuff, but as far as the Sprout green color is concerned, one of them ( I have 2) is getting a total colour makeover and the other (technically my girlfriends is staying the sprout green)

mexicanyella

Cool, thanks for the info. Yeah, as I recall the US Turbo Sprint had something like 71 hp, vs. the 48 @ 5100 mine had. And yup, there's a white square bodied one. I haven't seen one of those since the late 80s/early 90s. Neat.

Around '96-'97 mine was still running great on its third changed-at-the-proper-interval timing belt, soundin all raspy through its custom no-resonator-bigger-pipe-supertrapp exhaust, and getting kind of nasty inside from the chronic leaky door seals and general wear on the crap upholstery. It had been all over the midwest and to Colorado three times. Plus general college-kid stupid amounts of driving. The prior year I'd changed the brakes for the first time at 150,000, and found they still had plenty of meat left. Got sleepy late one night coming home from my girlfriend's house in a snowstorm. Pulled over for a quick roadside nap, and left the engine idling for heat. Got my foot on the gas pedal in my sleep and it must have revved up to about twelve zillion rpm in neutral the chucked the #1 rod through the side of the block. Woke up totally disoriented, engine on fire, snow everywhere...that was at about 170,000-180,000. Probably would have gone past 200,000 on the original clutch, struts, etc. the way things were going if I hadn't pulled that dumbass stunt. Oh well, I guess I got my money's worth and then some. New it cost $6,185. All in all it was a great little car, and probably the easiest thing to drive in snow I've ever had, including my CJ-5, Cherokee, Blazer...we have a hi-mileage CR-V now that is maybe a little easier, but no more nimble. The Spring was a lot better overall than the '90 Omni I had for a little while after that!

So what color are you going to go with instead of the sprout green?

3cyltrbo

I'm glad you were okay, but sorry I did laugh at that story.

Somehow mine was rated the same 71 from the factory that the previous generation was despite the numerous changes. If you ask me it had something to do with insurance or even the manufacturer CAFE rating or something --- because it always seemed impossible that adding multiport injection, a bigger more aggressive turbo, better breathing head, better ecu etc..etc... would result in the exact same power?

As for the Sprout Green Chinese CT-70, I really don't know what colour.

Sometimes I think white (ala Lady Dax) sometimes I think Gunmetal, in the end I think I will just drop it off to my painter friend and tell him to do whatever he wants.

mexicanyella

It wasn't too funny at the time, believe me, but it's more so now. I wonder how much better breathing that head was. As I recall my girlfriend's convertible was something like 55 hp instead of 48, at about the same rpm, and I kind of figured that was down to the throttle-body fuel injection instead of the tiny electronic progressive 2-bbl. carb. I figured they went to the inline-valve head to get more squish or swirl or something in a wedge chamber instead of the canted-valve hemi chamber, for emissions reasons. Maybe not. Could be the turbo had a totally different casting, or a much-altered one, for all I know, thus making my guesswork even more meaningless.

That was one great little engine; easy to work on and reliable as anything I've had since.