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sped66 Journal

Posted: 12:46 am Dec 12 2010
by sped66
This topic picks up where THIS THREAD left off. I reckon a lot of what I post in here will read a bit like a diary. Making observations & thinking out loud while I correct problems & make improvements.
Advice about anything at all is appreciated. :)

So I performed the KIPS checks & everything looks ok to me. Jetting feels good. After a lot of reading on this forum & some advice from friends, I changed the rear sprocket to a 50 tooth. A lot better, but mostly in a "non-stall" kind of way. I still think maybe I expect this bike to pull like a kdx250 in the super-low rpm range. And maybe that's my problem... not the bikes. Perhaps some of you could watch this short video & tell me if everything seems as it should. If so, I'll chalk it up to displacement envy.

[youtube][/youtube]

I'll be installing my Dyna-Ring soon so the clutch will likely slip down that low anyway, forcing me to keep the revs up for forward progress & making all of this a non issue.
The sprocket change has really affected the handling when twisting the throttle. Either the front end wants to launch or the rear wants to shoot out from under me, depending on traction & body postition. Kinda scary & unpredictable. Gonna take some practice to learn better control with this tighter gearing.

Pinch flats. I've never had one prior to owning this bike. Now I've had two in as many rides. (Rear tire at 12 psi.) UHD tubes are costing me too much money at this rate. I'm thinking golf would be cheaper & less frustrating, but I'll do some detective work on my wheel & tire this week. Something must be up somewhere. If I can't find an obvious problem, I'm seriously considering a Tubliss setup. Surely it'd be cheaper in the long run. Bought some spoons & will do my own tire work from here out.

Trans fluid level keeps going down. No leaks at the motor. Obvious culprit = crank seal I presume.

Bar risers are an improvement but still not comfortable enough when standing. Maybe some higher bars are in order.

Didn't get to test the new front Motoz tire yet. Didn't have time to install it prior to riding today.

Suspension is a bit stiff in the tight stuff but bearable for now. A prior owner must've been heavier than my 200 lb frame & beefed up the stock forks. Feels like it anyway.

Posted: 12:56 am Dec 12 2010
by Indawoods
Get RB'd....

What is the tire profile you are running on the rear?

Posted: 01:19 am Dec 12 2010
by sped66
>|<>QBB<
Indawoods wrote:Get RB'd....
Aight. Jan or Feb probably.
Indawoods wrote:What is the tire profile you are running on the rear?
Kenda Millville 110/100 with only 2 rides on it. IT rotation. (Reversible for ST)

Posted: 01:25 am Dec 12 2010
by Indawoods
Pinch flats are not normal on a KDX... as a matter of fact the 18" tire size is less likely to get them. I would say that if you are getting the tube changed somewhere... they are pre-pinching it with their spoons weakening the tube.

Posted: 02:54 am Dec 12 2010
by SS109
>|<>QBB<
Indawoods wrote:Pinch flats are not normal on a KDX... as a matter of fact the 18" tire size is less likely to get them. I would say that if you are getting the tube changed somewhere... they are pre-pinching it with their spoons weakening the tube.
Yeah, I have never had a pinch flat on my KDX and I run pressures as low as 7 pounds in the rear!

I don't know what it is about your bike but it doesn't seem to lug as good as my 200 and I'm running 13/48 gearing. I thought the 220 should have better low end than a 200. Hmm.

Posted: 10:00 am Dec 12 2010
by Indawoods
I can't tell the angle you are riding at but it seems to fall flat real fast. If that is a steep hill, feather the clutch to keep your R's up. In second gear it takes allot for mine to fall flat. I am running a 13/50 sprocket set. Your timing may be off.... that's is what it SOUNDS like to me.

Also... I gotta say that having video of the bike and sounds helps ...

Posted: 10:09 am Dec 12 2010
by scheckaet
I don't recall how a stock engine sounds and it's hard to tell how steep it is but it sounds odd, got the feeling it should keep going and lugging much further.
Are you sure the kips actuator is not busted? Sounds like it never get on.
Get the rb , should help

Posted: 11:32 am Dec 12 2010
by sped66
Indawoods wrote:I gotta say that having video of the bike and sounds helps ...
I was hoping it would. :grin:
The hill at the beginning isn't so bad. Those last two hills are steep enough that if you stop, it's a struggle to keep the bike from rolling backwards. Video always seems to flatten out hill climbs. A good way to judge is to look at the angle of the trees in relation to the ground. From there you have to envision the steepness in your mind.
scheckaet wrote:Are you sure the kips actuator is not busted? Sounds like it never get on.
I checked behind all of the KIPS covers as well as looked into the cylinder through the exhaust port. I performed all the tests prescribed to me in the old thread & it appears that everything functions as it should.

When I send off the head & carb to RB, I intend to really dig around in the motor & do some reading. Timing, KIPS, etc. I figure the kdx will be out of action for a month or two. Good thing for me I have two XRs to fall back on if I get antsy. (They've been giving me dirty looks the last couple of months.)

I'll post here if I figure out a cause for all of these damn pinch flats. Inda touched on my primary suspicion.... the shop might be too rough with my tubes. They won't get another chance to change my tires.

Posted: 11:54 am Dec 12 2010
by scheckaet
have you opened the clutch side and inspected the kips actuator?
If it's broken the rest might actuate fine manually but doesn't mean it will when the engine is running.
As for the tire change, why don't you do it yourself? I know it's a pain when you don't have the proper technic, try this:

made my life much easier...

Posted: 01:20 pm Dec 12 2010
by sped66
scheckaet wrote:have you opened the clutch side and inspected the kips actuator?
Yes. Looks good. Ports observed in the cylinder exhaust open & close when I manually manipulate the actuator.
scheckaet wrote:If it's broken the rest might actuate fine manually but doesn't mean it will when the engine is running.
How's this?
[youtube][/youtube]
scheckaet wrote:As for the tire change, why don't you do it yourself?
I'm going to. I guess you missed that in my first post. :wink:
Thanks for the link. There's lots of great instructional videos, including tire changes, over at Transworld. Check it out.
http://motocross.transworld.net/category/how-to/

Posted: 03:20 pm Dec 12 2010
by rbates9
>|<>QBB<
scheckaet wrote:have you opened the clutch side and inspected the kips actuator?
If it's broken the rest might actuate fine manually but doesn't mean it will when the engine is running.
As for the tire change, why don't you do it yourself? I know it's a pain when you don't have the proper technic, try this:

made my life much easier...

Posted: 07:06 pm Sep 15 2011
by sped66
Hate to dig up an old thread but I also hated to leave this story hanging. Figured I owed it to Vince to wrap it up, since he tried so hard to help me.

A leaking crank seal was the reason for my lack of grunt. I got RB'ed & installed new reeds at the same time so the end result was quite dramatic. The end.

Posted: 06:51 am Sep 16 2011
by gregp
Thanks for the update. It is always nice when someone posts a follow up to their original problem. Yes, aftermarket reeds will offer a significant boost in low/mid performance. I have no idea what effect a bad crank seal would have, but I imagine that lots of your mixture charge would be missing, and also induce a lean condition that would give you really poor low end power.