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91 cr500 questions

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I have not been in the 2 stroke world for many years,but recently aquired a 91 cr500.I will probably have this bike buried with me when I die ,or it kills me.One ride and I'm hooked.My question is,are any of you riding close to sea level.If so ,what are you running for carb jetting.Slow, main, needle.My setup is stock and consists of this. Keihin carb model no.pj27h. Slow55 main170 needle 4th groove a/s 1 1/2 turns. I run a mixture 20:1 with Bell Ray MC1. The barrel has been bored once to .030 with relatively new Weisco piston and rings. I will order Keihin jets so I know they will be true. I am looking to take some of the trial and error time out of the process.My second question is. The manual says to run my fuel at a 20:1 ratio. Was this ratio based on the lubricants of yesteryear . With the advances in lubrication technology is it possible to run leaner.I would like to run a castor mix,any recomendations. I hope this isn't one of those dumb "which oil is best questions". If so I appolgize now. I hunger for knowledge of my new beast so i can keep her running like the controlled hurricane I know it can be. Thanks in advance

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I run at sea level but will have to check jetting to get numbers. 20:1 is a lot more rich than I've ever run. I use Bel Ray MC1 and run it at 32:1 - have since I first got my '87 CR500R and have never had any problems. A lot of folks run 40:1. You will probably get as many opinions as there will be posts in reply on which premix to use and at what ratio. I'll check the jetting tomorrow and let you know what I'm running. I do have a ProCircuit pipe and silencer. I removed the airbox top cover also on both the '87 and the 2001.

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I forgot to mention that I'm running a fmf gnarley.Also the bike won't idle.Any help jbird would be much appreciated.

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Where in BC are you? Fraser Valley here. On my 1991 CR500 I have ran 20:1 sense I have owned the bike... the ELF oil is free :applause: I have been having the same idle problem as you. All stock carb settings besides my pilot jet. It has only started to idle for more that 5 secs with a 65. Then it leans out and dies. Going to try a 70 or 75 soon and see if that helps.

Milled head 0.030"

FMF Gnarly

PC silincer

Reed Spacer

Slight porting

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I forgot to mention that I'm running a fmf gnarley.Also the bike won't idle.Any help jbird would be much appreciated.

Idling woes are also indicative of an air leak...typically around the crank shaft seal. Have you run a pressure test to see that yours is sealed tightly ?

also, put me down as someone who's owned a '91 cr500 as well. Bought it for $1500, w/ Gnarly & FMF, EGorr engine work, 5th gear OD, Renthal twinwall. I installed a GPR, and ran C-12 in it. Rode and raced mine for a year, and then sold it for $1550.

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Hey peanut I'm in Surrey.Where do you do most of your riding?

I play around at the Veddar, Inch Creek, tracks. I'm going to be at the Herrling Poker run on the 1st Sunday of march. You going to be there? Shoot me off a PM if you would like.

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I just picked up a clean 89'CR500. The previous owner was running Amsoil synthetic 2000 at a ratio of 80:1. I have read that the 2000 synthetic Amsoil can be run at either 80:1 or 100:1 off their website. I have always run MC1 in my smokers at 40:1 without any problems. I haven't had a chance to get the 500 out and ride yet so I will wait and see what oil I keep running. But the 500 when I start it barely smokes at all.

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I didn't read all of the replies so, if this has been stated, my apologies. On the non-idle issue, make sure to check your air screw. My brother bought a '98 CR250 that wouldn't idle and we found that the former owner had screwed it all the way in. :applause:

We had a '91 and we're at sea level. We ran stock jetting with the needle leaned one clip to clean up the initial throttle response. Ran perfectly.

I currently run 32:1 Honda HP2.

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I pulled the 2001 carb off and apart. The main is a 172, slow/pilot is 55 but needs to be one size larger. The clip is the slot next to the top slot of the stock needle (one down from the top slot). Air screw is 1-3/4 out. I had to torque up the idle adjust to get it to idle and I can tell by the way it idles the pilot/slow jet needs to be one size larger. As I said, I have a ProCircuit pipe and silencer with the stock air filter and the top off of the airbox. I really think 20:1 is too much and you should try 32:1 on the premix. The MC1 is a synthetic oil and you shouldn't have any problems going more lean on the mix. As I said, most folks run 40:1. I live in north Galveston County and I'm about 12 - 13 ft above sea level.

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2005_0411_160236AA.jpgSweet bike man. I'm in Surrey too. I got a '91 that is a street legal supermoto as well as my dirt ride. And 20:1 is too much. i've been running 33:1 MC1 forever with no probs. I have a 39.5 PWK on it though. I run 175 main and I think a 55 pilot. The PWK is a lot nicer to tune and it's good for a cpl. HP according to Eric Gorr's tests. I'm running it in the Herrling Island hare scramble next week and the Desert 100 race in WA Apr. 15. It's going to Florence dunes Easter weekend as well. This bike gets used like a Hastings ho. The last pic was from last sunday. White rock beach. Supermoto rules. Who needs a kickstand when you can throw it in the bushes? Should see the looks I get on that thing.

2005_0411_160236AA.jpg

feb23-07004.jpg

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