m in sc
Well-known member
anything can be made to work. thats a carburated motor BTW.
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Manual Clutch Conversion?
- Thread starter m in sc
- Start date
Kev250R
Well-known member
I agree. Yamaha adding FI to the venerable TW would likely be what would get me to sell my '04 and upgrade.
m in sc
Well-known member
thats funny. one of the upsides to the DR650 i almost bought earlier this year was that it was still carbureted. lol.
m in sc
Well-known member
Im not sure what youre going to find for 200 bucks as a second bike... but all the parts are new if you dont have any.. 200 shipped.
Ive almost pulled the trigger a few times but I probably wont do it, the other bikes are all clutched. IF it was my only bike, id def do it, especially if i was riding dirt on it, as it makes the 'centrifugal clutch slippage on steep hills' issue ive read a few on here have go away. However, if a full grom motor comes along I might build it and swap it into the trail.
Ive almost pulled the trigger a few times but I probably wont do it, the other bikes are all clutched. IF it was my only bike, id def do it, especially if i was riding dirt on it, as it makes the 'centrifugal clutch slippage on steep hills' issue ive read a few on here have go away. However, if a full grom motor comes along I might build it and swap it into the trail.
m in sc
Well-known member
railbender posted this above. 189.98 shipped to the us as of today.
The CV-type carb the TW went to in '01 lets it run lean enough to pass emissions while not responding quickly enough to cause engine hesitation when you crack the throttle wide open from idle. Lots of carb swap options to address that if you're looking for better throttle response out of a tractor
m in sc
Well-known member
or, just learn how to tune the carb. its pretty easy, even on a stock cv type. you can shim the needle, get a different one, change the pilot jet, etc. you don't need to swap the carb.
CV carb will still have gradual lift of the throttle valve rather than immediate with the crack of the throttle, so depends on what the end goal is. IMO the newer stock carb (Mikuni CV that replaced that Teikei CV) is great with the right tune. A CV carb is totally appropriate for what the bike is, not a race bike or hillclimber that's being holeshot, but people still want it to respond like it is.
The older TK CVs (probably what the '04 has?) aren't just bad because they need a tune, they're bad because the parts are trash. Choke circuit clogs easily due to the casting, throttle valve diaphragm that doesn't hold up to gas with ethanol, jets that corrode or erode and open up to a larger size over time, etc. Rebuild it with the factory TK parts and you'll likely have the same issues again. You could fix them with a rebuild using aftermarket parts and there are some documented machining improvements that can be made to them, but there's something wrong about aftermarket parts being the solution to an OEM carb. May as well just buy one that isn't junk, that's what Yamaha did when they switched it to the Mikuni.
The older TK CVs (probably what the '04 has?) aren't just bad because they need a tune, they're bad because the parts are trash. Choke circuit clogs easily due to the casting, throttle valve diaphragm that doesn't hold up to gas with ethanol, jets that corrode or erode and open up to a larger size over time, etc. Rebuild it with the factory TK parts and you'll likely have the same issues again. You could fix them with a rebuild using aftermarket parts and there are some documented machining improvements that can be made to them, but there's something wrong about aftermarket parts being the solution to an OEM carb. May as well just buy one that isn't junk, that's what Yamaha did when they switched it to the Mikuni.
m in sc
Well-known member
they have a metered slide operation controlled by the pressure at the bellmouth. it opens what it needs, its a good design when tuned right. you will, absolutely, get a great shot out of the hole if you set it up correctly. i've worked on -dozens- of inline 4's, many singles and lots of twins with CV carbs, diaphragm type and aluminum slide type. they will. absolutely, respond as fast as a mechanical slide carb on a 4 stroke. the benefit is the velocity over the jet tube is stronger down low and controlled better at a WOT situation down low... with a diaphragmed slide. this has to do with the loss of circuit velocity over the jet tube with a conventional round or flat slide. In the case of a race bike, a mechanical slide can be better with a properly sized accelerator pump.
go take a ride on an ..old.. FZ1 (or bandit, or FZR600, yamaha v-max or.. etc... etc......) and tell me how unresponsive the CV carbs are off the line. then add an ivans jet kit... even better. this also includes opening the 'bleed' hole on the bottom of the slide so it responds faster... ie: tuning.
90% of the people out there will want to swap parts vs actually tune it correctly, this even applies to FI bikes..
.. side note. the reason to run a mechanic slide carb vs a diaphram is the on-off-on out of corners on a performance bike,, they typically will respond better once they are already in the rpms, but not usually noticeable on something as small and slow as a TW
.02
go take a ride on an ..old.. FZ1 (or bandit, or FZR600, yamaha v-max or.. etc... etc......) and tell me how unresponsive the CV carbs are off the line.
then add an ivans jet kit... even better. this also includes opening the 'bleed' hole on the bottom of the slide so it responds faster... ie: tuning.90% of the people out there will want to swap parts vs actually tune it correctly, this even applies to FI bikes..
.. side note. the reason to run a mechanic slide carb vs a diaphram is the on-off-on out of corners on a performance bike,, they typically will respond better once they are already in the rpms, but not usually noticeable on something as small and slow as a TW
.02
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Kev250R
Well-known member
I'll admit that I've never been much good at tuning Carbs or raising teenagers. The '04 TW I have now (I've owned it since '07) has always had issues with the carb. though lately (since the bike sits a lot more then it used to) they've been getting worse, to the point that prior to a week-long riding trip last Fall I bought a new Carb from Amazon and brought it with me 'just in case'. What I don't know is who made that new carb. I'll have to check if it's a Mikuni or not. Regardless it's an issue I need to address on that bike before summer riding season gets here.
m in sc
Well-known member
I get it, most people hate tuning carbs. (and electrical work).. i love doing both.
cleanliness is the key, then tuning. i hope the amazon carb works well. usually, they are copies. not all are bad, most are.. but i've seen good results from some. In the vintage world, the rule is always 'genuine brass' because the sizing protocols for jets, needles, etc, are all over the map in the aftermarket.
cleanliness is the key, then tuning. i hope the amazon carb works well. usually, they are copies. not all are bad, most are.. but i've seen good results from some. In the vintage world, the rule is always 'genuine brass' because the sizing protocols for jets, needles, etc, are all over the map in the aftermarket.
CTExplorer
Member
- Joined
- Jan 23, 2023
- Messages
- 79
Has anyone ever followed through with the full manual conversion on one of these? Very interested in the concept as the control and ability to rev and engage the clutch seems like it could really add to its capabilities of this motor in this bike.
Wayne @ The Speed Shop has done the conversion on a CT125. You could reach out to him: https://www.thespeedshopmini.com/contact
m in sc
Well-known member
So, while digging in there last night and today, I have all the parts to do the conversion.. sort of. you can use all stock grom parts, but minimally need the stopper from motogaga
the cover absolutely does fit, and you can either delete the kicker or open the hole in the grom cover. or use the whole conversion kit from the website above, but its certainly doable.
I am not planning on doing it.. yet, but might.
the cover absolutely does fit, and you can either delete the kicker or open the hole in the grom cover. or use the whole conversion kit from the website above, but its certainly doable.
I am not planning on doing it.. yet, but might.
bryanchurch06
Well-known member
- Joined
- Nov 4, 2022
- Messages
- 761
I thought you might get a kick out of this, I thought of you, dmonkey and a few others when I read itSo, while digging in there last night and today, I have all the parts to do the conversion.. sort of. you can use all stock grom parts, but minimally need the stopper from motogaga
the cover absolutely does fit, and you can either delete the kicker or open the hole in the grom cover. or use the whole conversion kit from the website above, but its certainly doable.
I am not planning on doing it.. yet, but might.
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m in sc
Well-known member
I dont view it as a dirtbike, and i prefer a clutch even when im in the dirt, so.. yup. different.