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143cc/160cc/165cc..which one to get?

18K views 29 replies 17 participants last post by  geezer  
#1 ·
I finished getting everything for my front and rear end, so it's off to the engine now. I've been trying to research all these big bore kits, but can't figure out which one to go with.

It seems the most amount of people throw on the 143cc kit with a 26mm carb. Some add the race head also. The 160/165cc kit's are like 50 more bucks than the 143cc kit, is there that much more power to be had with them over the 143cc? What about engine/starting problems? I'm guessing if you install them correctly you won't have any problems, like most things.

Right now I am thinking about this:
Trail Bikes 165cc Big Bore Kit and 28mm Carburetor Performance Kit for KLX110

I have like 400 bucks to work with. Any comments are appreciated!
 
#3 ·
I have a place that can do the machining, that is no problem. I just want power without spending tons of money for something that I rip around in the woods a couple times a week.

I was looking at the 165cc kit because of the minor price difference over the 143cc. But if everyone suggests the 143 w/ carb and crank, then maybe I will just do that.
 
#4 ·
I have the TB 165 kit with stroker crank and it flat out rips. Wheelie in all gears. If you don't mind stripping down the cases for machining then I like the 165. Have you ever split a set of cases before? Its not much fun and a good bit of work. I personally think the 143 would be plenty for trail riding and having fun on. Also if you splitting the cases get a 4th gear drum. I have mine torn apart right now because I didn't install the drum the first time.
 
#6 ·
I want THAT kind of power! Wheelies in all gears sounds like sufficient power. I have never split cases before, but my friend used to be a mechanic for a Honda dealership and said he will help me with tearing apart the engine for a couple cases of beer. I plan on getting a manual clutch kit, as well as the 4th gear drum, and plan on putting that all in when I take apart the engine so I don't have to do what you did...put in the big bore, put it back together, and then say oh crap I want to put something else in there now haha.

i personally have a 165 kit with stroker crank and ported an polished v2 head. being a 177 the motor is hard on all the internals (gears ect) along with the clutch. i used to have a 143 with a stroker an the old style race head. it was a 155. to be honest i most days wish i could go back to it lol
This is exactly what I wanted to hear. I want more power but not TOO much power that I have to rebuild the engine every 6 months. For my uses, trail riding and screwing around in the backyard, I want my bike to rip more without having to worry about the engine. Plus, then I will end up spending double the amount of money I want to because I will have to buy heavy duty internal parts to take the abuse the 165 power will put out.

I guess the 143 kit would be the best choice fort what I plan on doing. Maybe a race head if I can get one cheap.
 
#5 ·
i personally have a 165 kit with stroker crank and ported an polished v2 head. being a 177 the motor is hard on all the internals (gears ect) along with the clutch. i used to have a 143 with a stroker an the old style race head. it was a 155. to be honest i most days wish i could go back to it lol
 
#7 ·
i have my cases bored to fit a 165, but I'm currently running a 143 with stroker crank (155cc), and V2 racehead. I have no desire to add the 165 kit. The bike is already so fast. In the dirt, i can't even top out 4th gear because the places I ride are either too rough or too small. There is no way you need more than a 155 in the trails. However, running only a 143, it kinda lacks low rpm torque. If you wanted to save money and do without the stroker crank, i would go for the 165.
 
#15 ·
So I had a couple questions on the different race heads I saw on Tbolt's website. I wanna say a big THANK YOU to Vince Jr over there at Tbolt, he was patient with everything that I had questions about and just all around nice. A+ customer service to Tbolt, something you don't see much of anymore nowadays.

Definitely will be buying all my future parts from them...
 
#16 ·
My friend has a a YX racehead on his 143 and a VM26 carb. Its got kinda weak low-end punch, but from mid to top end it pulls good. I think a 143 with a stock head and bigger carb has much better low rpm punch, but the top end is not as good. I am not sure how the YX racehead compares to the Trailbikes racehead. I'm gonna assume they are pretty darn close.

Now a trailbikes V2 racehead is on a whole new level. Its also a lot more expensive.
 
#18 ·
Yeah I saw Tbolts had the YX head on their site. If I were to get a race head, I'd go big or go home with the V2. If I am going to spend the $200, I might as well spend the rest and get the V2. As of right now, I may just get the 143 kit and keep my stock head, go with the carb and stroker crank and call it a day.
 
#20 ·
I have the 143 with the stock head 26mm carb and a CHP exhaust. I love it! My friend had a port and polishing kit so we port and polished the stock head while it was off and cleaned the crap out of it. Not sure if it did much but I figured might as well while its off. I didn't have an exhaust on it for a week or two and the exhaust made a huge difference as well. My CHP exhaust is awesome the diameter of the pipe is so much bigger.
 
#21 ·
go big... 177 kit... for those who say 143 or 155 is to fast for close trail riding and cant max out 4th gear are obviously riding in fields or something... if your racing your gonna want every bit of power to get from 0-to whatever as quick as possible.
Just because you have the power doesn't mean you have to always use it
 
#28 · (Edited)
go big... 177 kit... for those who say 143 or 155 is to fast for close trail riding and cant max out 4th gear are obviously riding in fields or something... if your racing your gonna want every bit of power to get from 0-to whatever as quick as possible.
Just because you have the power doesn't mean you have to always use it
....or you don't really know what you're talking about. There is such a thing as having too much power for your riding ability and actually going much slower because of it. I dunno about where you're from, but around here a race is more than a couple laps and our tracks are real tight and technical (lack of space on this Island) It pretty much comes down to who can last the longest. I dunno about everyone else, but riding my 155 at full speed tires me out really damn fast. A 177 would just make me blow my load even faster.

Don't get me wrong tho, having as much HP as you can afford sure is FUN no matter how impractical and unusable.
 
#23 ·
CJperformance, you also have to realize that some people are just riding trails or goofing around and not out to put thousands of bucks into their bikes, or may not be able to spend a lot on their bikes nonetheless. I will say that yes, the v2 head is not expensive considering what you get, it's a bang for the buck. But do I need to spend almost $400 on just a head? Not really. I'd rather just get the 143 kit and a carb and call it a day. If I had more money to spend, then yeah I would look into the v2, but for now it's a bit unnecessary for my KLX.

I'm keeping my stock pipe on because of noise, the areas I ride are somewhat close to houses and most of the people in my area are not big on loud bikes. I have held off on getting my 143 kit since I picked up a new pistol, but plan on getting it in the next month.
 
#24 ·
I have a stock mod 155 (143 with tb stroker crank) and a full mod 172 (BBR 160 with tb stroker crank). While they are both vastly different bikes and have different uses I will say that the 155 motor sounds like the best fit for your riding. I absolutely love riding my stock mod, the 155 seems to make broader power than the 172, the 172 is faster for sure, but the power comes on later in the powerband. For woods riding and just HAVING FUN (thats the most important part anyways) go with the 155 kit, you will be more than happy.