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155 main with new mods.

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Hey guys,

Just got my bike back,with my new goodies.Stage 1 hot cam,CP 13.5.1 piston

and Ron's 07 R ported head.Haven' got to ride it yet,I want to put my hour meter on first to get a good check on how things go.I was wondering what size main jet would be good?Sea level to about 5000ft max.Full ccc modded but still have the X header with the R can.I'm running a 155 now,is this ok?

I'm thinking more like a 160-165?

Any body guess how much HP this bike will be making?36-38 HP?

I got at least 180hrs and over 1800 miles on my stock valves and piston.I'm sure in the end there, I was down a little on power but never had any blow by.I shimmed once at got 8 hrs out of it.When my head came off there was one valve fixing to snap as there was a gap between head and valve.Any way

good thing she stopped running and saved me a barrel.Looking for longer life out of this set up,but it will be hard to beat the previous stock life.:applause:

TWS.

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Sweet set up. You will have to give a ride report . What temp are you riding at? 0-5000' is alot of elevation to jet for. I would start with at least 165 maybe 168.

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165-posssibly a 170 on the main. I think you're optimistic on the HP rating.If I remember right Martin had his 307 with Ron"s cam dyno at 38 Hp 24 Ft lbs of torque. You're going to have to up the carb size for more Hp. I wouldn't worry about what it makes on the dyno, just how it performs in the dirt. Although it would be interesting to know what it makes.

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5000 ft would be the highest,and just once in a while.High dessert and Arizona, Prescott area.Most of the time in the low dessert.Temps 60-80*

When I talked to Ron, he said close to 37 give or take a bit add a couple more with fuel and CHM pipe.Sure would like to dyno and know.

My mechanic said the thing was running fine with the 155,but the 05 R with the same size carb starts at 165,(can't compare with the 06-07 bigger carbs)which Ron suggested 158-165.What will I notice or not notice with the 155 if I keep it in?Flat spot?I defintley don't want to be running lean.

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You may be right. I just reread Martins dyno results: 42.2 Hp out of that setup. So 37 should be in the ball park.

I ran mine with a 150 main, 07 R head and hotcams and didn't notice any problems. I gradually upped it to a 165, and it still runs great and honestly I can't tell the difference. The bike doesn't foul plugs and runs great, no flat spots and pulls hard.

Since yours is ported I would guess that you could easily run a 165. Your pretty much running a R setup so the R jetting chart would apply.

You can always start small and up the jet size. It only cost a few bucks to buy the jets and a few minutes to switch them out. The best way to jet a bike is with a dyno, but I don't know too many people that have access to them. I'd just break it in and do some high speed runs to see how it pulls at full throttle, make a change and do it again. It's probably better to have the main to fat than too lean.

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