Cj360 dies over 1/2 throttle

I have collected parts for a while and has only driven the bike 2-4km and i just took everything and cleanede befor i put it together, so i really dont know anything about jetting in the karburettors, but before i take it apart again i just want to hear your opinion on where to start.
It runs pretty normal up to half throttle, but over that, it just dies.
With or without mufler doesnt change anything.
I have KN-pods on it, i know you say thats a mistake, but i just want Them

Stock exhaust, K&N pods and stock carb jetting?

Kn pods, Stock exhaust, jetting i dont know, but i Think its standard

also make sure all ignition is in tune good luck

Stock jetting will be lean unless your living around 5,000ft
You need larger secondary main jets (but then you WILL get different problems with rich mid range around 4,500rpm)
Fitting K&N filters isn't a bad idea, you just need carbs modified

Well i have thought about ignition, all of the ignition parts look worn, but that would not infect throttleposition? Can the jetting be so far off, that it totally dies over 1/2 throttle. The problem is throttle-based, because if i only use half throttle, it will go fast;-)

Rene Holsebro said:

Well i have thought about ignition, all of the ignition parts look worn, but that would not infect throttleposition? Can the jetting be so far off, that it totally dies over 1/2 throttle. The problem is throttle-based, because if i only use half throttle, it will go fast;-)

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you MUST refresh and make sure that ignition is 100% perfect tune and condition before you do any carb tuning !! it could be one or a combination of ignition trouble that is causing issues right now
be sure and check the advancer for proper function, get new points, condensers and plug caps and sparkplugs otherwise you are just shooting in the dark

xb33bsa said:

you MUST refresh and make sure that ignition is 100% perfect tune and condition before you do any carb tuning !! it could be one or a combination of ignition trouble that is causing issues right now
be sure and check the advancer for proper function, get new points, condensers and plug caps and sparkplugs otherwise you are just shooting in the dark

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Holy crap I +1 this. My bike wouldn't even idle when warm because I couldn't get the timing right. Finally dialed it in with a timing light that clamps on a spark plug wire. Once the timing worked i balanced the carbs and they were like 90-10 to the right. Just by fixing the tuning I have a machine that runs reliably for hours.

yep one of the written cardinhell in stone rules is : ignition first ignition ignition first ignition ignition first ignition ignition first ignition ignition first ignition ignition first ignition .....go ahead say it fast

xB33A: just to be sure, do you Think i have to start with the ignition first

Rene Holsebro said:

Well i have thought about ignition, all of the ignition parts look worn, but that would not infect throttleposition? Can the jetting be so far off, that it totally dies over 1/2 throttle. The problem is throttle-based, because if i only use half throttle, it will go fast;-)

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if it burbles at 1/2 throttle, it is rich and your plugs should look black.

how long have your plugs been in?

can you post photos of them?
.

Rene Holsebro said:

Well i have thought about ignition, all of the ignition parts look worn, but that would not infect throttleposition? Can the jetting be so far off, that it totally dies over 1/2 throttle. The problem is throttle-based, because if i only use half throttle, it will go fast;-)

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Yes, the jetting is so lean with stock jets you may be able to carefully get to 6~6.5K rpm but then it will completely die on you. You have checked the diaphragms are good with no holes or 'repairs'?
At around 4,500 rpm the slides should start to lift, if bike will not go any faster they are not lifting or not lifting properly. Stuck slides are quite common
Oh, put at least which country you live in in your profile or sig (and anyone else who reads this do the same : )

Sorry guys, profil a bit better now 8)
I work a lot so i dont work on the bike every week, but i remember all your help, and Will check the next time i have the time. The diaphragms looks good, but maybe they dont slide Well enough

All good stuff.
You can remove the carb tops while they are still on bike to check slide movement and diaphragms, just use a magnetic screwdriver so screws don't go missing.
You need to very slightly (gently?) stretch diaphragm to check them, particularly around the nylon centre section
If they split, get new diaphragms from JBM Industries and drill out lift holes to 9/32" ( 0.140"~3.5mm) as diaphragms are slightly 'stiffer' so need some 'help'
I recently sent a set of modified carbs to Sweden (or Norway?) works out very expensive for shipping
I forgot which country already, short term memory problems
Still in touch with Kristian though, fine tuning is always 'fun'
Oh, if you have screw in air jets under diaphragm, check they are in the correct places, the 80 pilot air jet will have a massive effect if it's in wrong place and bike will just 'stop'
Drill out the 50 secondary main air jet to 1.20mm, it will really help mid range when you fit 110~125 secondary main jet (depending on exhaust system)

The diaphragms looks fine with no holes. I Can move Them up and Down easily with my finger through the back of the carbs. Regarding the tuning of the carbs.. I Will try to copy your info when i take the carbs apart again, what is your Price for at set of carbs?
Denmark is the most difficult country when it comes to automotive. And expensive, we pay up to 280% tax on import tax :'( : and everything is illegal
Sveden and Norway are almost as difficult but not as expensive as Denmark

Friend married a Danish girl, said whiskey (any spirits) were crazy expensive, about 10 time more than in Britain.
He had a lot of 'friends' every time he came home to visit his mother/sister then got back to Denmark
He ended up moving his wife and kids to Britain ;D