Author Topic: Project Clapped out 1998 KX250... what works?  (Read 16287 times)

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Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #15 on: February 14, 2018, 03:45:52 PM »
I don't care about the rest of the bike, I only care about the engine  :lol:
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #16 on: February 20, 2018, 03:17:54 PM »
Today we took the bike to a local shop to get some base line dyno numbers.



https://youtu.be/894qkgV4HIM
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #17 on: February 26, 2018, 12:52:05 PM »
Ok... Jason cleaned and polished the crank and rod.
Remember, send them off dirty and they generally come back dirty..   :-o













The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #18 on: March 17, 2018, 08:42:21 AM »
Well... we are a step closer to dyno results.. Steve Parris just finished cutting the crank webs...

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #19 on: March 17, 2018, 04:10:31 PM »
Just in from Steve.....

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline DoldGuy

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Re: Project Clapped out 1998 KX250... what works?
« Reply #20 on: March 18, 2018, 01:03:45 PM »
Going back together as it was with just the crank or.....?
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Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #21 on: March 19, 2018, 02:41:44 AM »
We are going to put in some new bearings there but everything else will be the same.
The plan is to make several changes over time and dyno each mod.
I'm tired of butt dyno results  :-o
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #22 on: March 19, 2018, 02:42:37 AM »
I'm also doing a KX500 but the approach will be a bit different as far as the order of the mods.
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Heniz

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Re: Project Clapped out 1998 KX250... what works?
« Reply #23 on: May 07, 2018, 04:23:39 AM »
Just in from Steve.....



Any credit to the turbo crank mod? ive been reading a lot about it on other forums and it seems to be that everyone has put it off as a fad. I ask because I just recently brought a stack of 97 kx250 parts and it came with this mod already done to the crankshaft and fitted with a royal rod. Havnt spun it up with some DTIs yet but it appears to be brand new. I have never heard of this mod before hand but I understand its to increase velocity in the crank case and although the theory is there wouldn't it push lubrication away from the lower rod bearing?
 :mrgreen:
Moto is life

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #24 on: May 07, 2018, 06:26:59 AM »
Steve Parris did the turbo mod for us.
Steve is the only person with a patent on the Turbo crank.
Turbo cranks were all the rage about 30 or so years ago.
Some say that it works, some say that it does not.
Steve says that he would not have spent 15K getting a patent on it if it did not work.
One thing I can tell you, not all Turbo cranks are created the same.
Most try fanning the charge up the transfers.
Generally they gained a bit off the bottom end and lost off the top end.
Steve claims that his design gets more all the way through the RPM range and adds from 600-1000 rpm to the top.
Also, oiling to the entire top end is improved...
That all sounds wonderful.... but does it work?
We will find out likely by the end of this week so stay tuned.
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #25 on: May 09, 2018, 11:04:55 AM »
Lazy roll on 5th gear wheelie..

https://youtu.be/c-t4_qovPcI

I think we are ready for a dyno pull...
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #26 on: May 09, 2018, 11:07:36 AM »
Turbo cranks are completely different to jet then a standard crank...
We went round and round before we started dialing it in..

The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline umberto

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Re: Project Clapped out 1998 KX250... what works?
« Reply #27 on: May 09, 2018, 02:58:43 PM »
It sounds stout; I can't wait to see what it will pull on the dyno.
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144

Offline sandblaster

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Re: Project Clapped out 1998 KX250... what works?
« Reply #28 on: May 09, 2018, 03:42:51 PM »
It sounds stout; I can't wait to see what it will pull on the dyno.

And then... drop in a new top end and see what happens.... And then start modding the top end and see what happens :-)
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline umberto

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Re: Project Clapped out 1998 KX250... what works?
« Reply #29 on: May 10, 2018, 01:02:51 AM »
Did you ever post a before HP number, or is that part of the suspense?
Perhaps I have a dirt bike addiction?

03 KX 250/88 KX 525/2017 KX250F - Goliath
17 KX250F/04 KX250
04 KX 250 - Lunchbox's Bike
05 KX 125/144