WooHoo - '90 KX500 runs

[NVR FNSH]

Finally got off my butt and cleaned the carb on my '90 KX500 and got it started today. Granted, it ran like crap but at least it ran and I rode it around the block in 1st gear. I'm running 91 octane pump gas (Chevron?) with Golden Spectro at 32:1 (previous owner ran GS so I've never experimented) with a 58 pilot, 175 main, R1369NS needle (CR250) and had to turn the air screw in to 1 turn (jettting specs from james dean). Bike has a FMF Gold Series pipe and Turbine Core silencer/SA. There was a bunch of spooge and the idle jetting was way off. I need to repack the silencer before messing with the jetting too much. Couple of questions for the other KX500 owners out there.
1. What pre-mix oil & gas are you running? What ratio? I'd like to stick to pump gas since we have two dual sported 4 strokes - much easier to only have one type of gas in the trailer. I'm not sure what race gas I can get locally but I'd be willing to use race gas if it will make that big of a difference.
2. What trans oil are you using? I'm using Maxima MTL Racing 80wt - it's what the previous owner used so I've continued using it.
3. I've read about re-routing the clutch cable in front of the frame down tube but I can't visual how it's routed. Can anybody describe it in detail or provide a decent picture? Clutch arm is already extended and I use a MP Terminator cable with a Works Connection perch/lever.
4. How far up are you setting the fork tubes to tighten the turning? I raised the forks on my '99 WR400 .5inch and it made a huge improvement. Is .5 inch too much on the KX500?

I'm trying to set the bike up for NorCal woods/D36 Enduro with an occassional desert trip thrown in.

Thanks,
Brian

 

[bbbom]

Better get it in gear Brian, your first occasional desert trip is less than a month away!!! :yeehaw:

 

[NVR FNSH]

Why do think I'm getting it running? The WR400 just isn't enough to keep up with you. Of course, it has nothing to do with my riding ability:(

Brian

 

[mhardee]

Originally posted by NVR FNSH 1. What pre-mix oil & gas are you running? What ratio? I'd like to stick to pump gas since we have two dual sported 4 strokes - much easier to only have one type of gas in the trailer. I'm not sure what race gas I can get locally but I'd be willing to use race gas if it will make that big of a difference. 

Running Mobil1 MX2T at 40to1; have run Klotz Techniplate at 32to1 when I just have to have a fix of that Klotz smell! 

2. What trans oil are you using? I'm using Maxima MTL Racing 80wt - it's what the previous owner used so I've continued using it.

Tried a few from Mobil1 to BelRay gearsaver and I always end right back at regular old Penzoil 10w30.. A lot of folks run ATF type F with good results..

 

 

[Farmer John]

Originally posted by NVR FNSH
1. What pre-mix oil & gas are you running? What ratio? I'd like to stick to pump gas since we have two dual sported 4 strokes - much easier to only have one type of gas in the trailer. I'm not sure what race gas I can get locally but I'd be willing to use race gas if it will make that big of a difference.

We use Yamalube R @ 40:1 in F&L fuel.

2. What trans oil are you using? I'm using Maxima MTL Racing 80wt - it's what the previous owner used so I've continued using it.

Valvoline type F ATF

3. I've read about re-routing the clutch cable in front of the frame down tube but I can't visual how it's routed. Can anybody describe it in detail or provide a decent picture? Clutch arm is already extended and I use a MP Terminator cable with a Works Connection perch/lever.

We use the Terminator cable with a CR lever & perch. I do not know if our routing is different than stock or not. When Rex & I were assembling it at the beginning of the season I just routed it the way that allowed for the fewest sharp bends.

4. How far up are you setting the fork tubes to tighten the turning? I raised the forks on my '99 WR400 .5inch and it made a huge improvement. Is .5 inch too much on the KX500?

I'm not to sure on the '90, but we normally run the forks around 12mm up in the clamps (same as what you are asking) for D-36 events and around 4-5mm out in Nevada.

Keep in mind I am basing this all on a 2002 KX that I was sponsored on for this past Best in the Desert season.

As far as pump gas, I really believe the KX could benefit from someone (read Eric Gorr) modifing the squish area on the head. I belive that would make the bike easier to jet & less fuel sensitive, but that is just my opinion. ;)

 

[NVR FNSH]

Thanks for the replies everybody. Looks like I've got some experimenting to do.

FJ - I seriously doubt I'd ever have any engine work done on this bike. For me it's just not worth that kind of investment. I'd really like to pick up a new 300cc two stroke - KTM or GasGas - but I have this bike and I can make some simple mods to see if I'm any more competitive on a 2 stroke. I know a KX500 isn't a comparable bike to a 300EXC or EC300 but it will be ~ $4k cheaper. The other thing is I'd like to try my hand at revalving and if I screw up a $1500 bike it's not that big of a deal. Do you run a flywheel weight on the race bike? I've read good results with the 14oz Stealhy unit on these bikes. I have a 12 oz wt on my WR and it made a big difference so I'm thinking I may spend the $100 on the KX.

Brian

 

[gwcrim]

1. What pre-mix oil & gas are you running?

MX2T @ 40:1

2. What trans oil are you using?

Mobil 1 5w30

4. How far up are you setting the fork tubes to tighten the turning?

I set the rear end to maximum recommended sag and lowered the front end about 7/8". I do very little high speed riding and was more concerned with lowering the seat height. 1/2" ought to be fine.

Oh and if you're interested there's a KX500 bulletin board here:

http://www.pitbull-racing.com/phpBB2/index.php

 

[bbbom]

Keep up with me, now that's a good one!!!! :)

I don't have any problem with my riding abilities, it's my lack of ability that seems to slow me down!!! :thumb:

 

[NVR FNSH]

Originally posted by gwcrim
Oh and if you're interested there's a KX500 bulletin board here:

http://www.pitbull-racing.com/phpBB2/index.php

Was there last night and read all 5 pages of posts. It's a pretty good website.

Farmer John - do you remember what jetting you were running for the D36 stuff? Was the motor relatively stock? It looks like C-12 is the most readily available stuff here in Santa Rosa so I think I'll give it a shot. From reading al the race fuel posts it sounds like C-12 will be a good choice for both the KX & WR.

Brian

 

[Farmer John]

Originally posted by NVR FNSH
do you remember what jetting you were running for the D36 stuff? Was the motor relatively stock?

58 Pilot
170 Main
#7 slide
Stock needle

Motor was stock then.

C-12 is good fuel. I used to use it prior to the F&L sponsorship.

 

[Camstyn]

I have to agree at getting the squish band "fixed" by Eric Gorr.. I tried the bandaid fix of a thicker head gasket, to reduce detonation.. Which did work, to an extent. In stock form, these bikes need race gas, no pump gas in the world is high enough octane for the stupid head design. You could mix 50/50 and get away with it I'm sure.

As for the forks, raise them as much as possible. I had mine pulled up probably about an inch, maybe a tiny bit less, and ran about 90mm of rear sag. I could still take my hands off the bars standing up in 5th gear across large, round river rocks without the front end twitching.

 

[NVR FNSH]

Originally posted by Cam Mitchell
I could still take my hands off the bars standing up in 5th gear across large, round river rocks without the front end twitching.

That I gotta see - got video?

Brian

 

[Camstyn]

Nope, no video, I was 15 and stupid at the time. I've never ridden another bike since that I could do that on, you could go as fast as you wanted across that stuff (no steering stabilizer, either) and it would hold a perfectly straight line.
I'm talking bowling ball / turtle sized river rocks, on a dry riverbed.
Of course, if I had found out that I was wrong, I probably wouldn't be here to tell you about it. :eek:

 

[92cr]

Hey cam mitchell was that out at Herrling Island or Davis lake?One thing I've noticed since switching to the big KX from my CR250 is the stability.It sure holds a line.Mind you we don't approach the same speeds as someone in california or nevada might in the desert.

 

[nephron]

I had clutch slippage on my 02 with ATF that resolved with going back to conventional motor or tranny oil. Maybe that's an ignorant and inaccurate statement, but I'm pretty sure it happened. Anyone else?

 

[Camstyn]

92cr: that was under the Agassiz-rosedale bridge when the water is low.

Where ya from? I'm in Agassiz.

 

[92cr]

Cam Mitchell:I'm from Abbottsford.Can't wait till the snow melts up in
the mountains and do some long distance riding.
Nephron:I felt that my cr250 had clutch slippage with 10W30 till I switched to gear oil.Never noticed any slippage after that.

 

[nickx]

On the KX 500, what happens when using pump gas, I just got a 99 (but can't ride it yet due to the cold weather) and put 87 or 89 octane in it, only ran it maybe 30 minutes total. What gas is recommended to run, or gas plus octane booster, I don't want to be rebuilding the top end on this thing all the time tho. Thanks for any info.

 

[gwcrim]

I bought my K5 in November and I'll use pump gas exclusively. If it causes any problems I'll work the engine over so that it doesn't. Race gas is expensive and hard to find for yer basic trail riding.

 

[Hogwylde]

Originally posted by gwcrim
Race gas is expensive and hard to find for yer basic trail riding.

Nice thing about living near the "racing capital" of the world is that race gas is available at the pump!!

I run 93 octane premium and have only heard detonation once on a really cold day I was out cranking hard on the grean beast. Eric's got my motor now for a rebuild and porting and I'm assuming since I told him I use pump gas, that he'll rework the head for it.

I'd NEVER run regular 87 octane pump gas. Why run the risk of detonation damage with that cheap stuff. Granted, premium isn't THAT much better, but when it's the best you can get short of $3.75+/race gas, might as well go for the best ya can.

 

[nephron]

I never had detonation with pump gas, but switched to C12 after noticing a "decreased" sensitivity to jetting. That's important out here where the temp can be 70 one day in January, and 18 the next...