reed cage 97 kx250
- Thread starter jimsowen
- Start date
OFICIALLY GETTING FIXED.
Put my 97 KX250 cylinder jug and head into hanks engineering to get....
1. Rebored to 265cc (68.5mm)
2. Exhaust valves serviced and champhered to fit new piston.
3. Get the squish tolerance recut to suit new forged piston.
4. Replace 1 head bolt that came loose while retorking.
COST $450 AUD Plus $250 AUD for piston kit and gaskets.
Hopefully its gunna be worth it. Still need to rejet it and do oil change. Dammn expensive top end rebuild. Will post pics when I get parts back from shop.
Put my 97 KX250 cylinder jug and head into hanks engineering to get....
1. Rebored to 265cc (68.5mm)
2. Exhaust valves serviced and champhered to fit new piston.
3. Get the squish tolerance recut to suit new forged piston.
4. Replace 1 head bolt that came loose while retorking.
COST $450 AUD Plus $250 AUD for piston kit and gaskets.
Hopefully its gunna be worth it. Still need to rejet it and do oil change. Dammn expensive top end rebuild. Will post pics when I get parts back from shop.
If you havent rejetted a big bore, it is really a crapshoot. If you simply do the overbore and size the head out to have a pretty stock type of compression ratio and combustion chamber shape, you would need to lean the critter down to make it run right. When you do as you have, and lots of us do, reshape for a different dome shape on the piston or change ratios, or change the port timing more than just restoring it, the jetting my change.
Some find you have to jet fatter just to get it to start as easily as before. For me, I do the chicken jetting and either stay the way I had it, or jet up a little. So far I have always been rich on the two strokes (not always on 4 strokes though).
what did you do with the ports on this one?
Some find you have to jet fatter just to get it to start as easily as before. For me, I do the chicken jetting and either stay the way I had it, or jet up a little. So far I have always been rich on the two strokes (not always on 4 strokes though).
what did you do with the ports on this one?
Ive never rejetted a bike before but I put a set of boyesen dual stage power reeds in it before I took it in to the shop, the instructions said that it needed 1 to 3 sizes leaner on the main jet. I didnt do this but the bike still hit harder in band than before with the original jets. I havnt pulled apart the carby yet but it the bike has had work done to it so it may not have stock jetting.
I was unaware I had to reshape the ports, the bloke I took it to has been making performance upgrades on bikes 2t and 4t for 35years so hopefully he knows to re-port it to the right specs.He said it will take approx 4 hrs worth of work to do all the machineing so hopefully thst includes reporting.
Thanks for your input. Ill keep you posted. Should be getting parts back by monday.
I was unaware I had to reshape the ports, the bloke I took it to has been making performance upgrades on bikes 2t and 4t for 35years so hopefully he knows to re-port it to the right specs.He said it will take approx 4 hrs worth of work to do all the machineing so hopefully thst includes reporting.
Thanks for your input. Ill keep you posted. Should be getting parts back by monday.
Also whats the difference in running a bike lean or running rich.
Just a guess but running lean would make bike starve for fuel and fart/splutter.?
running rich would provide too much fuel resulting in what problems?
I spose if it was rich I could run a hotter plug but then it would overheat maybe? These are all questions by the way as im a newby to tuning. Lol all help is appreciated and thanked.
Just a guess but running lean would make bike starve for fuel and fart/splutter.?
running rich would provide too much fuel resulting in what problems?
I spose if it was rich I could run a hotter plug but then it would overheat maybe? These are all questions by the way as im a newby to tuning. Lol all help is appreciated and thanked.
Rich is less expensive than lean. Sputtering is usually a sign of being too rich.
Too lean and you overheat. Burns Pistons etc.
Are they replating your cylinder or putting an iron liner in it? If they are not plating it i would reconsider. I know there are some other considerations, but the replete really is better.
Too lean and you overheat. Burns Pistons etc.
Are they replating your cylinder or putting an iron liner in it? If they are not plating it i would reconsider. I know there are some other considerations, but the replete really is better.
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you want to know jetting. this guy spells it out for you.
https://www.dirtbikeaddicts.com/content/threads/dirt-bike-jetting-101.5692/
here is another nice thread about mixture
https://www.dirtbikeaddicts.com/content/threads/pre-mix-101.5691/
https://www.dirtbikeaddicts.com/content/threads/dirt-bike-jetting-101.5692/
here is another nice thread about mixture
https://www.dirtbikeaddicts.com/content/threads/pre-mix-101.5691/
Those articles on jetting and oil are pretty hard to disagree with.
His example of 4stroke vs 2 stroke carburetors will be confusing to some who find themselves working on older 4 strokes. Most notably Brit bikes and yamaha tt and early xl and xr's that had bigger and better for the day VM Mikuni carburetors put on.
His example of 4stroke vs 2 stroke carburetors will be confusing to some who find themselves working on older 4 strokes. Most notably Brit bikes and yamaha tt and early xl and xr's that had bigger and better for the day VM Mikuni carburetors put on.
I read both articals and they make a world of sence to me. Thx. But just 1 thing I thought of while reading was for the main jetting you have to go with a new plug from start to W.O.T then pull in clutch and kill engine to get a plug inspection. Only problem is ill have to run in the fresh top end rebuild first with a few heat cycles and slow ride using only up to half throttle. Is that right? I pulled apart the carby to see her bitss.lol.
It is a KEIHIN PWK G279 AKGQ. It has main jet 172.. pilot 48.. and size 7 needle. And I cant find where the 1 to 5 clip position is in it.
http://www.jetsrus.com/carburetor/carb_keihin_PWK_series.html
this site says a PWK 38/71R non air striker has main 172 and a pilot 58. Which Iis the closest I could match it to. Can anyone identify the carby PWK G279 AKGQ.
It is a KEIHIN PWK G279 AKGQ. It has main jet 172.. pilot 48.. and size 7 needle. And I cant find where the 1 to 5 clip position is in it.
http://www.jetsrus.com/carburetor/carb_keihin_PWK_series.html
this site says a PWK 38/71R non air striker has main 172 and a pilot 58. Which Iis the closest I could match it to. Can anyone identify the carby PWK G279 AKGQ.
