When i kick start the bike it revs to the max. I have to use the OFF/RUN/OFF button to stop the engine from redlining. All my air and gas screws on the carbs are turned tight inward. 1975 RD350 stock
Vacuum tubes?
What bike is it?
By gas screw do you mean the idle screw? If that is screwed right in it will rev on startup.
Set airscrew at 1.5 turns out and idle screw so that it is just touching but not lifting the slide.
If they are vacuum tubes?? you need to block them off
do you mean oil injection lines or breather tubes? theres no 'vacuum lines' on rd carbs.
Is this your '75 RD350?
also make sure the slides aren't hanging up in the carbs for any reason. .02
Quote from: rodneya on January 07, 2021, 03:28:14 PM
What bike is it?
>>>>>>>>>>>>>By gas screw do you mean the idle screw? If that is screwed right in it will rev on startup.<<<<<<<<<<<<<
Set airscrew at 1.5 turns out and idle screw so that it is just touching but not lifting the slide.
If they are vacuum tubes?? you need to block them off
This.
Quote from: Striker1423 on January 07, 2021, 02:49:42 PM
Vacuum tubes?
Oops. I don't know what I was thinking.
Quote from: rodneya on January 07, 2021, 03:28:14 PM
What bike is it?
By gas screw do you mean the idle screw? If that is screwed right in it will rev on startup.
Set airscrew at 1.5 turns out and idle screw so that it is just touching but not lifting the slide.
If they are vacuum tubes?? you need to block them off
1975 RD350
Quote from: rodneya on January 07, 2021, 03:28:14 PM
What bike is it?
By gas screw do you mean the idle screw? If that is screwed right in it will rev on startup.
Set airscrew at 1.5 turns out and idle screw so that it is just touching but not lifting the slide.
If they are vacuum tubes?? you need to block them off
Yes, Idle screw and the air screw on the carbs. I have mine turned all the way in. I thought that would be a good starting point. I'll try what you said tomorrow. Disregard the vacuum tube comment. :)
Quote from: m in sc on January 07, 2021, 04:21:06 PM
also make sure the slides aren't hanging up in the carbs for any reason. .02
Slides aren't hanging up. They don't go all the way down, but aren't they supposed to have like a crescent moon shape at when they are down (off throttle)?
Crossover tube connected?
Can you post photos/videos of how your carbs are set up?
Are you running oil pump or Pre-mix? If Premix are the oil pump tubes in the carbs blocked off?
the front (motor side) of the slide should be able to hit bottom.
when the slide screw just touches, go in 1-1.5 turns and should be a good starting point. :twocents:
airscrew starting point 1.25-1.5 turns out
^^^ What mark said.
Print this out for bathroom and before bed reading.
http://www.mikuni.com/pdf/vmmanual.pdf
Quote from: NYSingh on January 08, 2021, 12:03:07 AM
Crossover tube connected?
Can you post photos/videos of how your carbs are set up?
yes, they are connected. Sure thing, I'll take a video :)
Quote from: pdxjim on January 08, 2021, 12:53:45 PM
Print this out for bathroom and before bed reading.
http://www.mikuni.com/pdf/vmmanual.pdf
This is awesome, thank you. Already started reading it.
Quote from: m in sc on January 08, 2021, 09:53:39 AM
the front (motor side) of the slide should be able to hit bottom.
when the slide screw just touches, go in 1-1.5 turns and should be a good starting point. :twocents:
airscrew starting point 1.25-1.5 turns out
is the "slide screw" the "idle screw"? and by "just touches" do you mean while "remove the screw, begin to screw it in and as soon as a thread catches, turn 1 full or 1.5 turns.
Quote from: patastinky on January 09, 2021, 01:34:15 AM
is the "slide screw" the "idle screw"? and by "just touches" do you mean while "remove the screw, begin to screw it in and as soon as a thread catches, turn 1 full or 1.5 turns.
Yes by "slide screw" he's referring to the idle screw. Thread each screw in until the pointed tip just contacts the slide, then turn 1 to 1.5 additional rotations. If you're looking into the bellmouth of the carb you will be able to see the slide slowly rising in the bore very slightly as you turn the screw in.
Air leakage symptoms??
Re-torque cylinder head, check reed block gasket....
You have some good advice to start with. I've had mine rev to the moon because the crossover tube wasn't on all the way. This was first start up in front of the wife and kids. Scared the crap out of all of us.
He said he had his idle screws turned in all the way "tight". That's the problem. All of the info and advice here is good, but he needs to eliminate one thing at a time. I would bet my next paycheck that if he adjusts the idle the way it's explained to do in this thread the problem will be solved.
thanks guys. I didn't have a chance today to work on the bike. Going to try tomorrow. Appreciate all the advice.Stay tuned.
:dawg: :dawg:
Quote from: JB Weld on January 09, 2021, 07:42:26 PM
This was first start up in front of the wife and kids. Scared the crap out of all of us.
I had a similar issue when I put my bike together. I spoke with Chuck Q a few times as he did the machine work. With no load on the bike and the throttle slides just cracked open slightly it would run away, having to hit kill switch. Was a combination of throttle cable hanging up when turning bars, fixed that and still did not correct. Ended up being an exhaust port leak from my J&L chambers. Took the flanges to work, faced off the plates and put a heavy paper gasket with some RTV on both sides (just enough to seal, not too much). After curing, bike fired right up and idled smoothly