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crf450 511cc with keihin pwk air striker carb wont start

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so i  brought this motor in parts so its a 2006 bottom end and a 2005 head 2006 wiring and 2005 cdi. it has 1mm oversized valves and ported head with hot cams stage 3 cam cp 13.5 to 1 comp cp piston but with the stroker crank its about 14.0 to 1 according to hotrods tech. i took the air striker 38mm carb from my cr250 and put it on the crf450 motor. the motor is in my gokart. my valves are set to spec. i lined up the marks for the timing and still notthing. i rechecked valves again and timing and its all good. i had the decompresion setup to spec to .025 but it was hard to kick over so i went with.026 and its easy to kick now. i put the car needle at number 4 one down from the middle and i have a 42 slow jet and a 172 main jet. does anyone have an idea what can be wrong im going crazy. once in a while ill get a ball of flame come out the exhaust pipe. im also not using a muffler just a header pipe.

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Do you have a FCR carb you could try? Is It common to use 2 stroke carbs on thumpers in the gokart world?

Did you use the right or 2nd mark on flywheel alligned with notch in left cover to set timing?

PS: the 05-06 come with a 40mm Keihin FCR carb.

Edited by HRC27

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No I don't have a for carb. I set the camshaft using the dot on the kick start side with the arrow.and the cam lobes are pointing toward the carb. I line the cam sprocket line on the left side to the arrow on the head. Am I missing something. 

Can it be the jetting

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1 hour ago, Tito Mercado said:

No I don't have a for carb. I set the camshaft using the dot on the kick start side with the arrow.and the cam lobes are pointing toward the carb. I line the cam sprocket line on the left side to the arrow on the head. Am I missing something. 

Can it be the jetting

I've learned here that that is not as accurate as removing the allen from the left cover and using the marks on the flywheel, aligning the right mark with the notch in the cover. Of course, the cam tower should be aligned with the mark on the sprocket. Never heard of not using the FCR which is quite different from a 2 stroke carb.

Left side pic may be a CRF250 but you get the idea.

IMG_8882-Medium.jpg

cam-timing-mark-3.jpg

Edited by HRC27

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I'm going to do that when I get home but I also belive  it's the carb. It worked great on the cr250 but I can get it to work on the 4 stroke. I don't want to spend the money on the frc carb because I'm going to be running a microsquirt  efi setup. I wanted to turn the motor on and break it a little and to make sure everything works before I change the piston again for a low compression piston and turbocharger

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Dude a turbo crf511r  EFI go-kart? Do you race it or are you just building it at see how fast you can kill yourself in the neighborhood? Sounds fun as hell but more than a bit sketchy

Edited by jblob

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No not for the street. To be honest I'm worki g with the nhra division  1 and the director so they can make go karts legal to drag race here in the states. I went to island dragway here in nj and wasn't allowed to race because they have no rules for them. The tech said he has never had a gokart go there to race. I had a ton of people coming up to me wanting to see me race and asking questions. I'm 37 years old and been racing for a long time and building cars and fabricating turbo parts for cars. So if you ever see a gokart at a drag strip it was me that help make it happen lol.

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14 minutes ago, Tito Mercado said:

No not for the street. To be honest I'm worki g with the nhra division  1 and the director so they can make go karts legal to drag race here in the states. I went to island dragway here in nj and wasn't allowed to race because they have no rules for them. The tech said he has never had a gokart go there to race. I had a ton of people coming up to me wanting to see me race and asking questions. I'm 37 years old and been racing for a long time and building cars and fabricating turbo parts for cars. So if you ever see a gokart at a drag strip it was me that help make it happen lol.

That is pretty legit man. Way to push for something you want to do. If more people did that they wouldn't be closing down so many riding areas. 

What are you planning for a turbo system? I know there have been boosted trx450's and a couple crfs so it's been done on the engine already.

How have the NHRA been about the safety protocol? I know for cars you need all sorts of crap as you get faster, helmet, roll cage/harness, battery cutoff switch,  etc, etc. Seems like a lot of that wouldn't be practical at all for karts. I would love to see some karts ripping down the strip at PIR locally. They race them on the road course so why not they are already approved to be on track. My main concern would be putting a kart in a lane next to a car and the kart getting crushed by a car losing its line 

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Well the rules are mostly about safety. I think it might be close to the a tv class but with the addition  of a 4 point roll bar that I already have s&w race cars build me and a safety  harness. Helmet fuel cut off. David is the director we email back and forth he thinks in a few months it will go down and I want to be able to put on a show and run fast time and set the bar high for fastest single piston gokart in the U.S. and maybe world if I can do it. I'm going to start build affordable  turbo kits once I get me a crf450r that is efi. I been building fast cars for a while now. Maybe I'll start a build thread on here

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19 minutes ago, jblob said:

That is pretty legit man. Way to push for something you want to do. If more people did that they wouldn't be closing down so many riding areas. 

What are you planning for a turbo system? I know there have been boosted trx450's and a couple crfs so it's been done on the engine already.

How have the NHRA been about the safety protocol? I know for cars you need all sorts of crap as you get faster, helmet , roll cage/harness, battery cutoff switch,  etc, etc. Seems like a lot of that wouldn't be practical at all for karts. I would love to see some karts ripping down the strip at PIR locally. They race them on the road course so why not they are already approved to be on track. My main concern would be putting a kart in a lane next to a car and the kart getting crushed by a car losing its line 

your right if you want something  you have to fight for it sometimes.i send about 3 emails a week along with my friends. Go karts will have their own class just like atvs only race against atvs

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That is awesome. Hopefully that gets rolling quickly

Man dont give me another excuse to build a gokart my wallet can't take more engines 

 

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3 minutes ago, jblob said:

That is awesome. Hopefully that gets rolling quickly

Man dont give me another excuse to build a gokart my wallet can't take more engines 

 

Man once I got the first one I got that I made electric I got hooked. Lol

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