Does RB mod help with spoo?

Jeb · Post by **Jeb** » 11:46 am Sep 29 2007

skipro3 wrote:. . . Straight C-12 didn't provide me as much power as premium pump gas either . . .

Did you attempt straight premium pump gas with Ron's race-gas-cut head? Or are you referring to the 50/50 mixture?

I'm a little off the subject here, but did you experiment with different ratios of race gas and pump gas? If so, were there any throttle response vs. power tradeoffs?

When I installed Ron's race-gas-cut head and started and kept a 50/50 mixture and experienced fantastic throttle response and had NO spoo at first, a little after riding about 16-18 hours.

Post by **Indawoods** » 11:50 am Sep 29 2007

I called our local Super-Motorsports store and asked who in town sells C-12..... "Uh... I don't know!" Useless!

skipro3 · Post by **skipro3** » 12:08 pm Sep 29 2007

[url=http://www.kdxrider.net/forums/viewtopi ... 7549#47549]
Did you attempt straight premium pump gas with Ron's race-gas-cut head? Or are you referring to the 50/50 mixture?

I'm a little off the subject here, but did you experiment with different ratios of race gas and pump gas? If so, were there any throttle response vs. power tradeoffs?

When I installed Ron's race-gas-cut head and started and kept a 50/50 mixture and experienced fantastic throttle response and had NO spoo at first, a little after riding about 16-18 hours.[/quote]

I worked my way from straight C-12 to a 50/50 mix. Stopped there because jetting was getting tough to keep consistent. The batches of pump gas varied so much in quality, the jetting kept changing on me. Especially with premium, who the hell knows how old that gas is sitting in a tank underground and blended every time they come to fill it up?!?

skipro3 · Post by **skipro3** » 12:14 pm Sep 29 2007

Vince,
click to here:
http://www.vpracingfuels.com/vp_01_fuels.html#leaded

follow the link called, "vp distribution centers". A pop-up map will home you in on a rep for your area. Call him and I'm sure he would be able to tell you who sells it in your neck of the woods.

Hmmmm.... if no one, then discuss with him the distribution you do for Amway oils, your affiliation with the web site you've created and perhaps you can rep for them!! Start stocking VP through the local motorcycle shops and it could be a nice little second income.

Post by **Indawoods** » 12:20 pm Sep 29 2007

Well... I called and left a message... hopefully I will hear back Monday.

wanaride · Post by **wanaride** » 08:06 pm Sep 29 2007

Man this is great info! I had given up on the spoo issue thinking it was a lost cause. Now I'm encouraged enough to look up a race gas distributor.

I still wonder why my son's KTM 50, which uses 87 octane gas, has a clean silencer tip while my bike, with 93 octane, looks like the spark arrestor is an oil well... I think his auto-injection system mixes at 60:1, but again, it probably isn't the oil anyway.

There I go thinking again. I just need to try the race gas and see how that goes.

Jeb, thanks for the link for VP.

Post by **Indawoods** » 08:18 pm Sep 29 2007

Remember... Higher octane gas has a slower burn rate... hence, unburned fuel.

skipro3 · Post by **skipro3** » 11:13 pm Sep 29 2007

But also look at the evaporation temperatures. C-12 is going to flash at a much lower temperature, and more consistantly due to the quality of the fuel. When the conditions are right, it will vaporize, (reach it's flash point) all of it. Unlike pump gas that might or might not because who the hell knows what it even is from one fill-up to the next?
With the race gas, your jetting will be very consistant and very easy to determine when you are going the right direction when playing with it.

BTW, carvr must be out playing this weekend since he hasn't piped up yet. Ha!!

One more thing. C-12 sells for $5 a gallon here. Premium pump gas is $3.20. Only a buck eighty seperates the two, cost wise.

One more thing, again. C-12 is 108 octane. Vince was pointing out that the higher the octane the slower the fuel burns. I don't know about that. I do know that it's less likely to flash at the temperatures generated in the head of a KX or a KDX. So not as likely to ping. If it does burn slower, and I've no reason to doubt it, then if timing is retarded (advanced? I get confused) to a point where the motor has more time to burn the fuel, then power will also be increased. I've heard that timing can provide more low-end power. Introducing a fuel that burns slower would be a good thing in that instance. I now seem to recall I set my timing to 3 extra degrees before TDC than stock. That should allow a slower burning fuel more time to burn before the exhaust port opens.

Which brings me to my very last thing. How would the KIPS valve affect the overall time that the fuel has to burn in the combustion chamber before it opens. It's an RPM thing, but does that mean at high RPM's there isn't as much time or engine cranking degrees to burn the fuel in the motor?

I don't blame anyone for not understanding my ramblings. I'm just sitting here on the porch in my rocking chair, killing time, a six pack and some Chinese food until my bike arrives. I re-read this and don't understand most of what I was trying to say.....

Jeb · Post by **Jeb** » 09:02 am Sep 30 2007

What Ski said . . . or, uh, in his own words, what he thinks he said

. . .

and just to add a comment about the race gas flash temp and octane level. C-12 is certainly the more popular race fuel but there are others. I started out with VP Racing Fuels VP-110 largely because I can get it from 3 sources in the Louisville area. It has a higher octane rating (110) yet the vaporization temp is higher (burns hotter) than C-12. Which is better? Is one better than the other? Who knows, like Jerry suggests it's quite complicated . . .

What does this mean if you're trying to cut back on spoo? It means that you have choices about which things like price, availability, and mix ratio become part of the equation.

2001kdx · Post by **2001kdx** » 11:18 am Sep 30 2007

My KDX spooed like no tommorow. 93 octane, 150/42. My RM has had absolutely 0 spoo since I got it. I think it's safe to say it won't be spooing until next year!

skipro3 · Post by **skipro3** » 11:25 am Sep 30 2007

spoo hoo

errrr.....

I mean boo hoo

Get well soon!!

2001kdx · Post by **2001kdx** » 01:54 pm Sep 30 2007

I'm rollin around in a wheelchair now - I might go work on my bike

Post by **Mr. Wibbens** » 03:48 pm Sep 30 2007

I don't worry about it

Prolly only way to get rid of it is to buy a 4 stroke

I ride with Carvr, prolly not a person on the planet that fusses more with their kdx than him. And his bike spoos out every single orifice you could think of!

But we do ride some pretty tight stuff. May only travel 20-30 miles in 6-10 hours. Last weekend when I rode the DR I only hit second gear like 3 times the whole day

Jeb · Post by **Jeb** » 04:41 pm Sep 30 2007

Just how many orifices does Carvr's KDX have?

Only on the West Coast . . .

skipro3 · Post by **skipro3** » 05:18 pm Sep 30 2007

hey Wib, I thought he got the spoo under control when he finally changed barrels. He did change barrels, didn't he? I thought he did.

Post by **Mr. Wibbens** » 05:35 pm Sep 30 2007

He really had it controlled when he put the stock S/A back on, but I guess it just stopped til it got a filled up??

Hopefully he'll chime in here soon

Not sure if he went riding on his twin 2 strokin couch this weekend or what?

Post by **fuzzy** » 10:52 am Oct 02 2007

Vince, I know my karting bud down there buys the 5-gal cans of C-12 in Springfield. I will ask him if he knows of anyone else. Can also try the local karting shop...They will know.

http://www.clearlight.com/~laukrace/2000/

They are right up the street from you.

There is always RB's race gas concoction too.

nykdxer · Post by **nykdxer** » 09:27 am Oct 04 2007

I'm also running c-12 50/50 with premium pump fuel with RB head for pump gas I have seen a reduction in spoo also. I paying allot more than ski was here in NY it's $60.00 for a 5 gallon pail. 12 bucks a gallon but to me it's wort it, my bike just seems to run better on it. I had a ping on the top that I was not able to get rid of put 50/50 in dropped the main on size and it was gone throttle response is also better.

skipro3 · Post by **skipro3** » 03:03 pm Oct 04 2007

With straight C-12 and a well jetted carb, your spoo could be further reduced, but I don't blame you at that price!! Are they charging you a deposit on the can? They used to here in California, but the California Air Resources Board (CARB) stopped them. They said an unsealed can could not be transported without a bunch of headache. Those BASTARDS!!!! Now I ended up with a boat load of 5 gallon metal cans. I think I'll work on replacing my pontoon boat by attaching them all together.

nykdxer · Post by **nykdxer** » 04:00 pm Oct 04 2007

no not charging for the can and I'm starting a collection also I wish they would take them back.

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Does RB mod help with spoo?