143 Takegawa cyl install.

[m in sc]

TO BE HONEST, YOU could do it with a die grinder and a cutoff wheel, and some tube to do what i did. however, i get it. the cat is here:

 

[AZ7000']

I also took out the screen on the spark arrester.

In a risk/reward assessment there is VERY little to gain by pulling that, only negatives if you ever go off pavement. I however live in the western forests and we have pretty good fires every summer... maybe you are in the south and everything is moist year around

 

[m in sc]

i removed the whole pipe from the endcap. (except the 'outside' part) no downside here. took a full bend out of the exhaust. Funny, when i did ride trails... never ran one either. But then again, that was mostly 2 strokes. Braap!

 

[chuckklr98]

In a risk/reward assessment there is VERY little to gain by pulling that, only negatives if you ever go off pavement. I however live in the western forests and we have pretty good fires every summer... maybe you are in the south and everything is moist year around

Smokers and ECO terrorist's cause ,more forest fires that a few bikes running around without spark arresters.

 

[dmonkey]

Curious to hear if there's evidence of bikes actually starting fires due to not having a spark arrestor. I've had 2-strokes and v-twins that will pop a flame or two out the exhaust, but I've only ever worried about fires in the case of tip overs, and being cautious not to park in dry grass with a hot header.

 

[m in sc]

some national forests (if not all) will require it and do checks for spark arrestors... they still do the 'stick' test?

I'll never go riding in a nat forest w the 125. so, im not worried about it one bit. and if i was going to, i probably would be just fine with it in there. .02

 

[dmonkey]

Yeah, they still check along with OHV permits. Was just curious if it's based on reality or "what if"s.

 

[AZ7000']

I don't know, but the fires are real, an insignificant screen as far as power vs no real power advantage is questionable IMHO. I would put the chances of a ct125 starting a fire at roughly zero though...

 

[m in sc]

No one is telling you to remove yours. I use mine in different ways than a lot of other CT owners... at the end of the day I don't expect 95% of anybody to do what I do. I mean, also am putting a full spohn adjustable suspension in the back of my 4 door 66 galaxie. Its just what I like to do. Some people might find it interesting. I can tell you, removing the last muffler restriction did infact help some in conjunction with everything else i've done. Exhaust restrictions, in general, don't have any upside for performance, period. I'd put mine back in if i ever was going to go rolling around a national forest, i mean i still have it. Theres also about zero chance that will ever happen as well.

 

[m in sc]

for those that think reliability can be an issue with a 143 or any big bore. from the msx (grom) owners page.

 

[tuff tunica]

Thanks for the post. I've got a 143 Yuminashi on order. Piston, cylinder and cam. I'm scheduled with a local machine shop to just check clearance spec's between cylinder and piston and also ring gap. I've read that these can sometimes be a bit too close. I feel that if the spec's are correct and the engine is broken in and maintained properly, this set up can be very reliable.

I'm at 6,000 feet above sea level. The engine is probably putting out about 7.5 hp stock. Hoping with this set up to get closer to 10 hp. Nothing too radical. I really doubt an additional 2 hp is going to seriously compromise or stress the engine as long as it is not abused.

I'll post up the kit and install once it is received.

 

[m in sc]

thats currently what im running piston/cyl wise, the piston is a better design vs the takegawa.... which really surprises me. I checked mine and it was spot on out of the box, got lucky. i guess they have tightened up their QC over the past few yrs. as a side note, the yuminashi cyl is a re-sleeved oem one, but it still retains the '124cc' stamp for those that live in countries with a stricter modification inspection, this may be useful.

 

[chuckklr98]

thats currently what im running piston/cyl wise, the piston is a better design vs the takegawa.... which really surprises me. I checked mine and it was spot on out of the box, got lucky. i guess they have tightened up their QC over the past few yrs. as a side note, the yuminashi cyl is a re-sleeved oem one, but it still retains the '124cc' stamp for those that live in countries with a stricter modification inspection, this may be useful.

The 124cc stamp is nice. Keeps the the busybody's away, and when you smoke someone you can claim its still 124cc. lol

 

[SneakyDingo]

This entire thread is A+ quality, complete with photos and explanations. Big bore kits fall solidly into "entertainment" not "life circumstances" category for me, but it'd be a free beer for you for sure if we turned up at a bar & you were willing to chat about it.

 

[tuff tunica]

this is a few pics from installing the takegawa 143cc cylinder. I also updated the cam chain tensioner with a koso unit, and installed a pcx150 honda injector at same time. wasn't bad. about 4 hours.

prior to this, already installed a TB cam and an efie fuel management device, and de-catted stock pipe and made a new free-er flowing head-pipe. Pulling alternator rotor requires the correct puller which i already had. everything here can be purchased through hard racing, except the efie unit. Only reason i used that was an adjustable ecm isnt availabel fro the CT125's as of yet as they are different than the cubs, groms, and monkeys as of 10-2021.

stock chain tensioner:

hole with copper washer is oil galley bolt for tensioner. this needs to be primed back up upon reinstall for auto tensioner,

koso chain tensioner and idler installed:

stock cyl to left:

stock piston to left.

could serve bean dip out of that bowl.

and new piston in. rest is just stock bolt in stuff.

Getting ready to install my 143 Yuminashi. Having a very difficult time getting the alternator rotor nut loose?!? Not certain that it is not a reverse thread. Can anyone confirm if this is standard, right-tighty thread or reverse thread. I'll post up some pics of my build in a separate thread once it is complete.

Thanks in advance.

 

[m in sc]

sorry, just saw this. regular thread. air impact gun helps.

 

[tuff tunica]

sorry, just saw this. regular thread. air impact gun helps.

Thanks much. Already solved. Yuminashi 143 kit in with cam, injector and Yosh exhaust. I'm planning to do a write up soon.

 

[dmonkey]

Looking forward to reading it.
I ordered the Takegawa e-Stage Alpha Bore Up Kit 143cc with sports cam and FI Controller TYPE-e, it's being shipped now but I'll probably hold off for warmer weather before installing it.

 

[m in sc]

ah you're going to wire it in? curious to see how this works.

 

[dmonkey]

It's the plug and play one, they finally came out with one specific to the CT125 ECU