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So after disassembling my engine to the point of splitting cases, it dawned on me that since I'm sending my crank and cylinder in for service, I could send the whole engine in for not much more and get it all rebuilt right and not worry about it.
Of course while it's at a shop, I am going to have it ported, and I'm looking for some input:
I've never actually rode one of these in any condition to have comparison. Should I get porting done to improve bottom end, top end, or balanced overall improvement?
I'm not a racer, and I like tractor grunt - but do these bikes already have that?
I'd love to hear your input.
92 kdx200 E

If you like tractor grunt and you ride mostly woods, then I think you just answered your own question. If it were me Id get something to improve power everywhere, but then again I ride everything from tight single track to occasional motocross track days.

Friedom wrote:So after disassembling my engine to the point of splitting cases, it dawned on me that since I'm sending my crank and cylinder in for service, I could send the whole engine in for not much more and get it all rebuilt right and not worry about it.
Of course while it's at a shop, I am going to have it ported, and I'm looking for some input:
I've never actually rode one of these in any condition to have comparison. Should I get porting done to improve bottom end, top end, or balanced overall improvement?
I'm not a racer, and I like tractor grunt - but do these bikes already have that?
I'd love to hear your input.
92 kdx200 E

yes, they have good low end power. you can get more, that's for sure. put emphasis on where you spend 90% of your riding time, and forget the other 10.

works for me

Thanks. How is the factory power distribution to start with? I've been on 4ts for awhile and used to grunt, and I like it. If that's already the bike's strong point, though, I wouldn't overdo it.
I do enjoy wheelies though!

Friedom wrote:Thanks. How is the factory power distribution to start with? I've been on 4ts for awhile and used to grunt, and I like it. If that's already the bike's strong point, though, I wouldn't overdo it.
I do enjoy wheelies though!

good tractable torque for a 200 2t, smooth power delivery, pretty linear. falls on its face on top end power in stock form. an aftermarket pipe is a must if you want to improve performance. boyesen reed petals are nice, vforce reed block is nicer. remove the airbox "snorkel" and rejet your carb and I think you will be happy. factory silencer does not hinder performance. you will get more power everywhere and still retain that smooth powerband

KDXrider1989 wrote:

Friedom wrote:Thanks. How is the factory power distribution to start with? I've been on 4ts for awhile and used to grunt, and I like it. If that's already the bike's strong point, though, I wouldn't overdo it.
I do enjoy wheelies though!

good tractable torque for a 200 2t, smooth power delivery, pretty linear. falls on its face on top end power in stock form. an aftermarket pipe is a must if you want to improve performance. boyesen reed petals are nice, vforce reed block is nicer. remove the airbox "snorkel" and rejet your carb and I think you will be happy. factory silencer does not hinder performance. you will get more power everywhere and still retain that smooth powerband

It's got a fmf gold pipe, factory silencer, airbox removed, already jetted up from what I can tell. I don't know what the reeds in there are, I'm kind of planning on replacing them though.

Riding single track, open roads, open desert, PowerLine roads. Never been to a track, though.

I'm leaning towards balanced power.

While I'm sure that there are gains to be had from porting, most of the KDX faithful around here, myself included, choose to go with the the RB Designs head and carb mods, along with pipe, reeds, etc.
This is a killer combination. Makes good power everywhere.

Good point. I haven't read much about porting around here, and the price of carb update and squish is comparable.

I'm not sure how I feel about needing to run high octane, though.

I wrote an email to Ron at RB asking if premium pump gas was required for a motor with his head mod. He said that while he thought that it was a good idea and cheap insurance it might not necessarily be a must. His advice was to try to run lower octane and pay close attention to whether there was any detonation.
I haven't tried it yet because I like to run premium. I asked because I was taking the KDX on a dual-sport ride through some austere areas that only offered 87-octane. I ended up being able to sort it out so I only had to run a slight amount of 87, mixed in with mostly 93.
I believe that Jeff Freddette at FRP offers some porting options for the KDX. I'm not sure about the results but I know that Jeff is a guru and I'd be confident that I was getting good stuff. It's been discussed and the concensus is that if you're looking to modify your motor you should either go with RB or FRP exclusively. The parts might not be optimal if mixed and matched.
My vote is the RB mods.

TheRadBaron wrote:I wrote an email to Ron at RB asking if premium pump gas was required for a motor with his head mod. He said that while he thought that it was a good idea and cheap insurance it might not necessarily be a must. His advice was to try to run lower octane and pay close attention to whether there was any detonation.
I haven't tried it yet because I like to run premium. I asked because I was taking the KDX on a dual-sport ride through some austere areas that only offered 87-octane. I ended up being able to sort it out so I only had to run a slight amount of 87, mixed in with mostly 93.
I believe that Jeff Freddette at FRP offers some porting options for the KDX. I'm not sure about the results but I know that Jeff is a guru and I'd be confident that I was getting good stuff. It's been discussed and the concensus is that if you're looking to modify your motor you should either go with RB or FRP exclusively. The parts might not be optimal if mixed and matched.
My vote is the RB mods.

Makes sense, but I still have to re plate my cylinder, and neither of them does that to my knowledge. Would love to send this to a 1 stop shop.

Porting would be an excellent idea at this point. Case matching makes a great improvement. Bolt ons are great, but only amplified by porting. RB makes great mods that could be added to to a ported moter. But it's a little more difficult to add porting once its all fresh and together.

ecojbr wrote:Porting would be an excellent idea at this point. Case matching makes a great improvement. Bolt ons are great, but only amplified by porting. RB makes great mods that could be added to to a ported moter. But it's a little more difficult to add porting once its all fresh and together.

Case matching - that's another advantage to sending the whole motor in!
Thanks for commenting on porting amplifying other mods, like the squish mod. I wasn't sure how they would interact, but I imagine that if done right they'll only do great things.
Maybe I well send in the whole engine after all. I'm going to hold off on sending parts to anyone else beyond that for work until I get some seat time with things together.

Friedom wrote:

ecojbr wrote:Porting would be an excellent idea at this point. Case matching makes a great improvement. Bolt ons are great, but only amplified by porting. RB makes great mods that could be added to to a ported moter. But it's a little more difficult to add porting once its all fresh and together.

Case matching - that's another advantage to sending the whole motor in!
Thanks for commenting on porting amplifying other mods, like the squish mod. I wasn't sure how they would interact, but I imagine that if done right they'll only do great things.
Maybe I well send in the whole engine after all. I'm going to hold off on sending parts to anyone else beyond that for work until I get some seat time with things together.

What is Millennium going to do and how much does it cost? I am considering doing an EG 225 kit on my bike, but would consider whatever Millennium has to offer.

Don't know about millennium but my cylinder goes in the mail tomorrow for 225 kit. Will give you results as soon as it returns. Also gonna swap theRB carb for an air striker so will have results on that also

6 Riders wrote:

Friedom wrote:

ecojbr wrote:Porting would be an excellent idea at this point. Case matching makes a great improvement. Bolt ons are great, but only amplified by porting. RB makes great mods that could be added to to a ported moter. But it's a little more difficult to add porting once its all fresh and together.

Case matching - that's another advantage to sending the whole motor in!
Thanks for commenting on porting amplifying other mods, like the squish mod. I wasn't sure how they would interact, but I imagine that if done right they'll only do great things.
Maybe I well send in the whole engine after all. I'm going to hold off on sending parts to anyone else beyond that for work until I get some seat time with things together.

What is Millennium going to do and how much does it cost? I am considering doing an EG 225 kit on my bike, but would consider whatever Millennium has to offer.

I'm tossing around whether to do which services, but my quote, IIRC, is as follows:

Cylinder plating 200
Port and polish 125
Crank rebuild and parts 175
Crank case bearings 36
Rebuild engine 350
Box and all shipping 120

I'm supplying an engine rebuild kit, wiseco piston kit, and new steel kips valves. .

They did actually give me a discount on engine rebuild, since mine is almost completely disassembled already. It was like 10% off above price.

The $120 is shipping both ways?

Is the $350 labor only or does that include replacing all the bearings & bushings inside the engine?

Tedh98 wrote:The $120 is shipping both ways?

Is the $350 labor only or does that include replacing all the bearings & bushings inside the engine?

120 is shipping both ways. They send an engine container for you and you get their bulk shipping rates.
The engine rebuild is labor only, I got a rebuild kit for 80 I think.
They said they'll match cases, align the power valves, and actually include a warranty on the fully assembled engine. It's only for like 30 days, but a nice thought.
And I don't have to scrape off gaskets, gunk, grime, dirt, and whatever this stuff is. [emoji106]

Friedom wrote:

Tedh98 wrote: I got a rebuild kit for 80 I think.

What is the rebuild kit? The gaskets and seals?

Tedh98 wrote:

Friedom wrote:

Tedh98 wrote: I got a rebuild kit for 80 I think.

What is the rebuild kit? The gaskets and seals?

Yes. I guess engine rebuild gasket and seal kit is more accurate.

Maybe I missed it, but are new transmission bearings/bushings accounted for anywhere there?