Big Bore? Standard? Rb mods which one? +

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PHOENIX
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Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Heyo ,
i commented on a big bore post from 2007 , someone said make a new thread, SO here it is

I have my new 1997 kdx 200 , , got some piston slap So tore her down. The bore has some scoring but managable It seems.
I'll be riding it on and off road so it will sorta have to be reliable :)

Questions Please
1.Does the barrel have a sleeve from factory?

2 I found a Big bore kit locally in australia
https://www.ebay.com.au/itm/172810419920?ul_noapp=true

says it can go to 250 cc
will this give me problems with overheating?

I asked the seller

HEy Mate ,
ive got a 1997 kdx 200. . doing top end now , saw this kit. So other than having the barrel oversized and sleeve fitted, what other modifications do i need to do?
Does the kit come with everything to do the job?
Thanks

New message from: performanceindustries2010 Top Rated Seller(2,112Red Star)

Yes the kit comes with a sleeve, piston and gasket kit that is all required. On top of resleeving the barrel you will also need to open up the squish /chamber on the head to 73mm but that's it.
Cheers


3. I can source a Standard wiseco top end kit for $305 AUD locally ,
thoughts on just doing that , then the rb mods at a later date ? should be enough ay?

4. Or do i go ahead and do a big bore kit and then rb mod ?

thanks
PHOENIX
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

And then there is this STD one locally on ebay

https://www.ebay.com.au/itm/KAWASAKI-KD ... SwCx5bK3u2


im floded with options and cannot decide please help the newbie! :)
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Re: Big Bore? Standard? Rb mods which one? +

Post by bufftester »

The OEM barrel is NOT fitted with a sleeve but is plated (i.e. nikasil). IIRC you can't overbore without reworking the KIPS as well, not just a straight drop in. The RB mods are good, but he's not taking on any more work right now, and logistically its kind of a PITA to do it from outside the US. IIWM I'd get the cylinder measured, and have it replated if out of spec and go standard, retaining the KIPS. Again, not sure what the plating options are outside the US, but we have a bunch of Aussie KDXrs here on the forum that can chime in.
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Re: Big Bore? Standard? Rb mods which one? +

Post by John_S »

My vote would be for option 3 but not RB'ing the 21 year old carb. A PWK needle jet (emulsion tube) is not replaceable and they wear out, so do the slides over time.
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Re: Big Bore? Standard? Rb mods which one? +

Post by doakley »

It general, my past experience with big bore kits has been less than satisfactory. Not specific to the KDX but to other Kawasaki 2 strokes. We took a 175 up to 230 cc and found the clutch wasn't up to handling the power. Never really solved that problem. Also to get the most benefit of the new bore, we had to upsize the carb. More $$. And then we realized the 175 pipe was inadequate for the upsized bore....more $$. My take away was if you want a 250, buy a 250.
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Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Thank you So MUCH !!
Doakley
John_S
Buffester
All of this info is very good stuff! I really appreciate it!
Buffester and Doakley -- Great info about big bore kits !, so much more work and mods to do I didnt think about !
I think I will def stay with a standard kit. Double check the bore prior to ordering the new ashtray.
John_S - So If I did rb the old carb it wouldnt be up to spec hey. better a new one. maybe I'LL think about that later down the track
Is there any mods I can do locally, other than rejetting?
also Ive heard I could have the head skimmed to lessen the squish clearance. Thoughts?

Please and Thankyou!


I might start another thread specifically for my bike.
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Re: Big Bore? Standard? Rb mods which one? +

Post by KDXGarage »

Look into Eric Gorr 225 kit. I think it is 223 cc.
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Alright , so I removed the barrel and now see a bit where the plating has taken a hike. Also some cracks in between the intake ports.

God Damn it!
I dont want this to turn into a money hole.
do I have to oversize it anyway now ? or can I clean her up , hone it and run it? or pay $500 for a New barrel?

Image
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Re: Big Bore? Standard? Rb mods which one? +

Post by KDXGarage »

"The bore has some scoring but managable It seems."

MMMMMM. Maybe not.

You are not going to just "clean it up". :shock:

The cylinder needs a repair and replate.

At some point in time, I added a data field so people could put their country. Repair options wherever you are at may not be the same as what other members have.

I would not have mentioned Eric Gorr had I went to the top and dug into your post to be sure of your location first.
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Re: Big Bore? Standard? Rb mods which one? +

Post by pumpguy »

PHOENIX wrote:Alright , so I removed the barrel and now see a bit where the plating has taken a hike. Also some cracks in between the intake ports.

God Damn it!
I dont want this to turn into a money hole.
do I have to oversize it anyway now ? or can I clean her up , hone it and run it? or pay $500 for a New barrel?

Image
I'm afraid bikes, especially dirt bikes IME, are kind of like boats.

There is a definition of a boat that goes BOAT: A hole in the water, surrounded by fiberglass, into which you throw money.

You know what BOAT stands for, don't you? Bust Out Another Thousand.

And then of course there's the saying about the 2 happiest days in a boat owner's life; the day he buys his boat, and the day he sells his boat.

For many of us, classic dirt bikes are kind of a disease. I'm just thankful it's not as bad as Classic Tractor Fever.

But yes, I'm afraid they do cost money; it's just the way it is.
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Re: Big Bore? Standard? Rb mods which one? +

Post by KDXGarage »

Phoenix, I put your country in your location field.

Hang in there on the bike. Like pumpguy said, they are money pits.
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Re: Big Bore? Standard? Rb mods which one? +

Post by bufftester »

The minus...you definitely need a repair/replate

The plus...there are facilities down under that do electrosil/nickasil repair/replating

I would guess you're looking at around $300 just for the repair/replate, but after it's done (if done well) it will last another 20 years!
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

[quote="Jason"]"The bore has some scoring but managable It seems."

MMMMMM. Maybe not.

I wrote that before I removed the bsrrel to see the obvious Nikasil hole

cheers for the other info anyway.
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Yeeeeeaaaahhhh Im not into spending craploads on it. .
cant i just hone her chuck a bit of quick steel on her? Hah ah a
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Yeah I know how much Boats can suck banks , Ive owned a V8 ski boat and im a marine engineer. I would never own one.
ha ha
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

SO IM going to do a science experiment.
Im gonna do a quick hose, bit of 1200 to clean her up and chuck a top end kit in her.
Lets see how long it lasts
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Post by KDXGarage »

Look up muriatic acid and cylinders to remove the molten globs of aluminum.
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PHOENIX
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

Gday everyone! You will be happy to know that I cleaned the bore up and looked better than I thought , chucked a pro x piston in er and now sheez Fangin!!!
I will post pics n such soon.

One question. Top end power...... Im ride my old Cr 80 and it pulls like a schoolboy to infinity but my KDX drops off, Im sur the kips is operating, is it just a different power style as its a 200?
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Big Bore? Standard? Rb mods which one? +

Post by Molly's 70 »

The KDX is not tuned like a motocross bike. KDX has more low end power, race bikes are more high rpm power. It would be normal for the powerband to fall off before the race bike.
If you lend someone $20, and never see that person again, it was probably worth it.
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Re: Big Bore? Standard? Rb mods which one? +

Post by PHOENIX »

HEy Molly! that explains alot!!!! It does have great low end mid power. not the snappy crack of the cr80.

I love it.

thanks
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