i'm looking at the KITACO 75cc bore kit for my crf ($200), supposedly it works w/ stock carb and intake. anyone had any experience w/ this? are there any other kits i should consider? (i don't think takegawa makes one) looks pretty simple to bolt up and shouldnt take to long to do, and i don't wanna put too much stress on the clutch or trans so i'm hoping this will work out well. also will i need to (or should i) rejet the carb or make any other changes to the fuel delivery, intake, oil pump, etc.? should i get some reinforced clutch springs? any ideas? i don't want to cut down on the engines longevity or create potential problems/failures in the future... (trying to cover my bases) ha ha. thanks.
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Buy the 88cc kit from Dratv. Its more worth the money.

 

thanks but i don't want quite that much, knowing myself that'd just be the perfect excuse to get a 4 speed manual clutch, suspension, aluminum frame and swingarm, billet wheels, the list just goes on and on... like i said i'd rather not have to get a new carb., intake, oil pump, clutch springs, etc. (can't say i won't though) and i'm the type that doesn't wanna feel like i 'half-assed' anything when it's all said and done.
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Then buy the big bore kit with the cam, carb and intake for $275 from

http://www.hondatrailbikes.com/parts/parts.html


Its way more worth the $$$$$$$$$$$$$$

 

fabfivefiddy is selling them for the same price... that way at least its from someone you know......

 

I have been wondering the same thing about if the cam and carb and intake really make much of a difference on an 88 kit. Is it worth the extra $100 for the intake stuff? Also, is a better oil pump necessary? thanks

 

check it out

http://www.twobros.com/cgi-bin/shopp...y=010-1-05-502

two bro's

88 kit with cam use stock carb with I think a 62 or so mainjet and exhaust and you'll be pimpin

for 269

for the 200 I would just toss in the 69 bucks and go with the 88 kit that you're not going to get that bored with as soon as the 75 kit

IMO

 

Before I put the big carb and intake on my 50 my bike made 3.6 hp at the rear wheel with the 88cc kit, jetted with foam filter.
Bone stock the bike made 1.5 hp

After my friend ported the entire head and matched the intake, and added the 20mm carb my bike now makes 5.1hp at the rear wheel. I haven't even added a cam or exhaust yet!!! After the exhaust and cam I know it will be at 6hp+ at the rear tire.

We make a dyno run after every mod to see what it did for performance. Its so nice to have a friend with a dyno in his garage. You should see how fast my little 50 spins the 900lb drum on his dyno. We laugh our asses off every time we make a dyno pull with the minibike. In the spring we may do the stroker crank...we will just have to wait and see.

The heavy duty oil pump DRATV sent us is the same exact Honda pump as was in my z50. Same numbers on the side. I think its getting enough oil.

 

that was pretty much exactly what i wanted to know.

How hard was it to port the 50 head and what did you use? A dremel? I think someone (Fab5fiddy?) said that it was pointless to port a 50 head. I dont know what the reasoning was behind that though.

So what did the bike feel like w/ the stock carb and 88cc kit? Was it still quite a bit faster than stock?

I guess it would be worth it to get the kit w/ the carb and cam then.

So are u saying that the stock oil pump will work good enough.

THANKS!

 

Nobody can tell you its useless to port a stock 50 head. It does help gain big hp but you can never achieve the same results as if you ported a 70 head so in essence it may not be worth it for some people. Since I already had the 88cc piston for the 50 head I kept it and it would have had to spend another $200 on a 70cc head. I'll probalby get one though when I do the stroker crank in the spring. When I do the crank and 70 head I want at least 10 or 11 hp at the rear tire.

I picked up BIG hp gains porting the 50 head and port matching the intake. Add the carb and proper jetting and I made an extra like 1.6 hp or something. My bike is making 5.1 hp now without a cam or exhaust so I'm pretty impressed to say the least.

The 16mm stock carb was too small to flow enough air to my motor at high RPM's the 20 is kinda overkill but will be needed for later mods. A 18mm carb would be ideal.

My friend used his dremel tool. He's been building race bikes for 25 years or so working on the 50 a break from all the other work he has to do. He spent like 7 hours on my 50 head.

Its kind interesting because my friend's 8 year old son has a XR70 that has all the same mods mine has....in exhange for doing some of the work on my bike I buy his kid aftermarket performance stuff...for the kid I say. Anyway with the same stuff 88cc kit, carb etc my bike has, but with the domed piston and 70cchead his bike makes about 1.2 hp more than mine so I know the 70cc head is woth at least 1.2 hp which on a 50 is a lot. Its nice to have 2 different setups like that to compare the 2.

There is a 40 foot hill next to his house that we climb with the bikes. Its nice because we can see how much power our bikes are making when climbing the hill. Stock I couldn't make it to the top of the hill in 1st gear. Now I go up in second with no running start.

The oil pump seems to be fine. I guess we'll just have to wait and see.

The last thing he's doing right now is putting in my Kitaco heavy duty clutch springs so I can hopefully keep from destroying the clutch for a while.

Make sure if you take the head apart you buy a set of good heavy duty valve springs.....DRATV sells them for $12. They will definately be needed if you start making big HP on your 50.. Without them you can easily float a valve. The springs are pretty trick in that they are a double spring set up with one inside the other for springing the valves back quick.

 

what's involved w/ installing clutch springs? i've done that kind of stuff on 600s and cars but never on a fiddy...
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