Hey everyone, new here. Great site with lots of info! I recently got this sles from my in laws. It had been sitting for many years. 440 kioritz.Had problems with the original Bendix. Had it running ok for a day the it went south. MNeeded a float needle and a float but could not find one.
Any way i replaced the bendix with a vm34 from a 1995 xlt 580. I changed components to what I thought a good start
Throttle valve: 2.0
Main jet : 280
Pilot: 30
Float valve: 1.5
Air screw 1.0 out
Needle on middle notch
I got it to run but barely. Was terrible rich and flooded motor out within a minute. I am unaware what needle and needle jet this has. Could the needle and needle jet cause this to happen? I figured I was lean on my main jet, possibly a bit rich on pilot. But if you held it
WO. it would barely run 1/2 speed and atomized fuel was shooting back out of the carb neck.
Now I looked up a service manual for a 76 cyclone 440 and it it recommended a different needle than I have so I ordered one. However the needle jet box just listed "q-0"... Okay what size q-0???? WS considering a 159q-0. Any input?
They also recommended a smaller pilot which I will try and an even larger main. Which I will order and wait first to see what the new needle does. Any help would be great. Thanks!
mikuni conversion ?s 75 model 600
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turn-n-burn
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400brian
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- Real Name: James T. Kirk
- Location: South Central Wisconsin
Re: mikuni conversion ?s 75 model 600
At idle, the only thing coming into play is the pilot jet. A 30 is probably large, but I would think it would run on it.
Open up the air screw...remember, this meters air. opening leans the mix, closing richens. If opening it up makes it idle better, a 25 pilot might be better.
Are you sure the choke is closing? This will cause all the symptoms you describe if it is not.
Main jet: if you are talking about a 440 piston ported engine ( not reed ) then I suggest you go smaller. 220, 230, or lower if need be. Your plugs will tell the tale.
A quick look at 76 Cyclone specs indicate the following:
Needle jet Q-O
Jet needle 6FL14
slide cutaway 2.5 on the 340 3. on the 440
pilot 20
You can't just put a carb off a Cyclone on a piston ported engine, as experience has shown them to be way too rich, mainly because of the main jet sizing.
Open up the air screw...remember, this meters air. opening leans the mix, closing richens. If opening it up makes it idle better, a 25 pilot might be better.
Are you sure the choke is closing? This will cause all the symptoms you describe if it is not.
Main jet: if you are talking about a 440 piston ported engine ( not reed ) then I suggest you go smaller. 220, 230, or lower if need be. Your plugs will tell the tale.
A quick look at 76 Cyclone specs indicate the following:
Needle jet Q-O
Jet needle 6FL14
slide cutaway 2.5 on the 340 3. on the 440
pilot 20
You can't just put a carb off a Cyclone on a piston ported engine, as experience has shown them to be way too rich, mainly because of the main jet sizing.
Last edited by 400brian on Tue Dec 30, 2014 4:32 am, edited 1 time in total.
'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
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turn-n-burn
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- Real Name: tom halvorson
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Re: mikuni conversion ?s 75 model 600
Thanks for the reply! I am using a lever choke on the carb til I get a cable rigged. I can visually see it close so unless its not sealing that part is OK. I was told to jet it like a cyclone with a 330 main but this is a piston port motor and a cyclone is reed, correct? I have a 200 main and a 30 pilot I will try on the stand to check. If that doesn't help I'll be trying the needle adjustment.
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400brian
- Posts: 5627
- Joined: Wed Jul 20, 2005 12:00 am
- Real Name: James T. Kirk
- Location: South Central Wisconsin
Re: mikuni conversion ?s 75 model 600
See if it runs. But it really has to be run under load to get the real picture.
Be careful, without a load, it will run lean.
Be careful, without a load, it will run lean.
'09 Vintage Challenge Survivor, and I wasn't late for supper!
'10, '11, '12, '13,'14,'15,'16,'17, '18, 19, 20, 21, 22 Vintage Challenge Survivor !
72 400 restored, Father bought new in '71
73 X8 restored
'74 340 green machine
'74 X8 9 time VC finisher
'78 Spitfire in progress
2 '75 340S 1 running, one on deck
'78 LF 440 future CC clone
'73 Skiroule RTX 440, 500 mi.
Re: mikuni conversion ?s 75 model 600
Hi there! I just completed a mikuni conversion on my 72 400 jd. you might check your choke adjustment. Make sure you have it set
right or you will be running rich all the time.
right or you will be running rich all the time.
Re: mikuni conversion ?s 75 model 600
Did you change out your crank seals?
You said the sled had sat for years.
You said the sled had sat for years.
Todd Schrupp
Milbank SD
Milbank SD