Rehab thread roketa - Page 7

Angus67 · 12-07-2017, 04:04 PM

The nut bottomed out on the shoulder in the middle theof the stud

Megadan · 12-07-2017, 10:02 PM

Sounds like you just need to take a a thread or two off of the side of the stud that goes into the manifold flange so the shoulder seats up against the flange. Or the shoulder/shank on your stud is too long. and thicker than the flange of the carburetor. In that case you could try to run a die down and thread it a little further.

Angus67 · 12-12-2017, 09:25 PM

Got another manifold. The studs already look better. And the shoulder on the studs does fit into the carb flange. I got it all back together. The bolts to the engine, and the stud nuts snugged up to what i feel is fine fir aluminum threads. Started right up, second kick cold. I let it warm up, and tried to bring it down to idle. Runs fine, but fast with the choke choking, but when i open the choke, it starts sneezing again like before. I checked for a vacuum leak, but found none.
Now, i have a confession.... when i first took this carb off, the screw on top wasnt screwed on straight. I had to use pliers to thread it straight. Thist could be my vacuum leak, but didnt find one there. Also, is there supposed to be a washer or oring to help seal the top? I noticed a resess it the top were one may have been.
So my thinking is.... at choke, the main comes into play, with out choke the pilot is either plugged, wich it wasnt when i cleaned it out, or the 33 pilot isnt big enuf. I dont see how it wouldn’t be big enuf to run smooth, because I’m running the stock air box, and a un molested muffler.
Main thought..... put in a 38 pilot, or/and the top of the carb is stripped letting in unmetered air.
Thoughts??

Angus67 · 12-12-2017, 11:18 PM

Guys, i have also been following crackerjack’s thread in the pure dirt section. Very good info on carb tuning there. Although he has a 26 and i have a 27, the tips and tricks with tuning are the same. I have a 33 pilot, and my needle is in the third notch mix screw is 2 turns out.

Angus67 · 12-13-2017, 08:32 PM

Cmon guys...am i on the right track?

Ariel Red Hunter · 12-14-2017, 11:28 AM

Quote:

Originally Posted by Angus67

Got another manifold. The studs already look better. And the shoulder on the studs does fit into the carb flange. I got it all back together. The bolts to the engine, and the stud nuts snugged up to what i feel is fine fir aluminum threads. Started right up, second kick cold. I let it warm up, and tried to bring it down to idle. Runs fine, but fast with the choke choking, but when i open the choke, it starts sneezing again like before. I checked for a vacuum leak, but found none.
Now, i have a confession.... when i first took this carb off, the screw on top wasnt screwed on straight. I had to use pliers to thread it straight. Thist could be my vacuum leak, but didnt find one there. Also, is there supposed to be a washer or oring to help seal the top? I noticed a resess it the top were one may have been.
So my thinking is.... at choke, the main comes into play, with out choke the pilot is either plugged, wich it wasnt when i cleaned it out, or the 33 pilot isnt big enuf. I dont see how it wouldn’t be big enuf to run smooth, because I’m running the stock air box, and a un molested muffler.
Main thought..... put in a 38 pilot, or/and the top of the carb is stripped letting in unmetered air.
Thoughts??

In my opinion, a vacuum leak is not coming from the top of the carburetor. There is always a vacuum leak there due to the throttle cable opening in the top of the carb body. The throttle slide controls, but does not eliminate vacuum leaking past it from the top. You can either use grease on the threads, or electricians tape around the top to see if it makes any difference. There is one way to get a vacuum leak the way you describe - either a warn slide, or a warn carb body....ARH

**JerryHawk250** · 12-14-2017, 03:16 PM

If I remember correctly you are still running the stock carb right? Did you have some issues with the idle mixture screw? To me it sounds like a pilot jet or idle mixture issue. Or as ARH stated it may just be a worn out carb. May be time to just buy a new VM26 Mikuni carb.

Angus67 · 12-14-2017, 10:00 PM

Yeah jerry. Im thinking that too. Is the vm26 a good carb for the ohc 200

Megadan · 12-14-2017, 10:23 PM

Quote:

Originally Posted by Angus67

Yeah jerry. Im thinking that too. Is the vm26 a good carb for the ohc 200

The VM26 clones are no different from the Keihin clones these bikes come with in terms of size/specs.

Angus67 · 12-14-2017, 11:10 PM

If there is no difference, why in one a pz27, and the othe pz26? Must be a difference somewhere

**JerryHawk250** · 12-15-2017, 07:47 AM

There is a difference in those two.

The VM26 or a PZ30 would be better suited for the 200cc.

Link to Carb https://www.amazon.com/gp/product/B0...070_em_1p_1_ti

Ariel Red Hunter · 12-15-2017, 12:05 PM

Quote:

Originally Posted by Angus67

If there is no difference, why in one a pz27, and the othe pz26? Must be a difference somewhere

Sure there is. pz 27 means that the part of the carb that meets the head or intake pipe is 27 mm, pz26 the hole is 26 mm. The Mikuni VM 26 has a 26mm VENTURI, and is 30 mm where it attaches to the intake pipe. The advantage of the VM 26 is how easy it is to get genuine Mikuni jets and throttle slides for their carbs. Mikuni's are a popular up-grade because they are so tunable...ARH

Angus67 · 12-15-2017, 02:23 PM

Thanks. I know what the numbers mean, i should just asked what is a good upgrade. Mikuni it is then.

Angus67 · 12-16-2017, 08:50 AM

Should be here jan 15th

Angus67 · 12-29-2017, 10:17 PM

Got my vm26 today. I opened it up to clean it out. The machining is quite good. Looks sturdy. The needle was on the richest slot. I put it in the middle. It has 20 pilot and 100 main. I turned the idle mix out 2 turns. Being a bigger carb, it was a little tricky getting it mounted. Threw a foam filter on it and started kicking. I smelled gas right away and had to give a shot of either to get it to start.
I kept it alive with half choke. The idle screw seems to not do much. I got a idle reaction when I snugged up the ferrul on the throttle housing. It still pops and snorts like before. BUT it sounds different. It sounds like it real rich. It will load up and pop, then sound ok for a moment, then sound blubber. The idle is not racing, so I don't think I have a vacuum leak.
I think it's pulling gas from the main. If I give throttle, it clears up. BUT if I let it drop, it's back to weird idle
Another thought is perhaps the idle mix is too far out. I have it 2 out.
Since its very difficult to adjust mounted on the bike, I shut it down for the night.
Tomorrow I will turn the idle mix to 1 and 1/2, see what happens. If that doesn't do it, I'll drop the needle to the second slot
I'm running non-ethanol gas.i also have a shot of seafoam in the tank.
Thoughts?

12-07-2017, 04:04 PM	#91
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	The nut bottomed out on the shoulder in the middle theof the stud __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
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12-07-2017, 10:02 PM	#92
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 7,884	Sounds like you just need to take a a thread or two off of the side of the stud that goes into the manifold flange so the shoulder seats up against the flange. Or the shoulder/shank on your stud is too long. and thicker than the flange of the carburetor. In that case you could try to run a die down and thread it a little further. __________________ 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2010 VFR1200F - http://chinariders.net/showthread.php?t=20708
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12-12-2017, 09:25 PM	#93
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	New manifold Got another manifold. The studs already look better. And the shoulder on the studs does fit into the carb flange. I got it all back together. The bolts to the engine, and the stud nuts snugged up to what i feel is fine fir aluminum threads. Started right up, second kick cold. I let it warm up, and tried to bring it down to idle. Runs fine, but fast with the choke choking, but when i open the choke, it starts sneezing again like before. I checked for a vacuum leak, but found none. Now, i have a confession.... when i first took this carb off, the screw on top wasnt screwed on straight. I had to use pliers to thread it straight. Thist could be my vacuum leak, but didnt find one there. Also, is there supposed to be a washer or oring to help seal the top? I noticed a resess it the top were one may have been. So my thinking is.... at choke, the main comes into play, with out choke the pilot is either plugged, wich it wasnt when i cleaned it out, or the 33 pilot isnt big enuf. I dont see how it wouldn’t be big enuf to run smooth, because I’m running the stock air box, and a un molested muffler. Main thought..... put in a 38 pilot, or/and the top of the carb is stripped letting in unmetered air. Thoughts?? __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-12-2017, 11:18 PM	#94
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	Guys, i have also been following crackerjack’s thread in the pure dirt section. Very good info on carb tuning there. Although he has a 26 and i have a 27, the tips and tricks with tuning are the same. I have a 33 pilot, and my needle is in the third notch mix screw is 2 turns out. __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-13-2017, 08:32 PM	#95
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	Cmon guys...am i on the right track? __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-14-2017, 03:16 PM	#97
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,525	If I remember correctly you are still running the stock carb right? Did you have some issues with the idle mixture screw? To me it sounds like a pilot jet or idle mixture issue. Or as ARH stated it may just be a worn out carb. May be time to just buy a new VM26 Mikuni carb. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
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12-14-2017, 10:00 PM	#98
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	Yeah jerry. Im thinking that too. Is the vm26 a good carb for the ohc 200 __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-14-2017, 11:10 PM	#100
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	If there is no difference, why in one a pz27, and the othe pz26? Must be a difference somewhere __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-15-2017, 07:47 AM	#101
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,525	There is a difference in those two. The VM26 or a PZ30 would be better suited for the 200cc. Link to Carb https://www.amazon.com/gp/product/B0...070_em_1p_1_ti __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel Last edited by JerryHawk250; 12-15-2017 at 09:07 AM.
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12-15-2017, 02:23 PM	#103
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	Thanks. I know what the numbers mean, i should just asked what is a good upgrade. Mikuni it is then. __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
	0

12-29-2017, 10:17 PM	#105
Angus67 Join Date: Oct 2017 Location: shelton, Washington Posts: 167	Got my vm26 today. I opened it up to clean it out. The machining is quite good. Looks sturdy. The needle was on the richest slot. I put it in the middle. It has 20 pilot and 100 main. I turned the idle mix out 2 turns. Being a bigger carb, it was a little tricky getting it mounted. Threw a foam filter on it and started kicking. I smelled gas right away and had to give a shot of either to get it to start. I kept it alive with half choke. The idle screw seems to not do much. I got a idle reaction when I snugged up the ferrul on the throttle housing. It still pops and snorts like before. BUT it sounds different. It sounds like it real rich. It will load up and pop, then sound ok for a moment, then sound blubber. The idle is not racing, so I don't think I have a vacuum leak. I think it's pulling gas from the main. If I give throttle, it clears up. BUT if I let it drop, it's back to weird idle Another thought is perhaps the idle mix is too far out. I have it 2 out. Since its very difficult to adjust mounted on the bike, I shut it down for the night. Tomorrow I will turn the idle mix to 1 and 1/2, see what happens. If that doesn't do it, I'll drop the needle to the second slot I'm running non-ethanol gas.i also have a shot of seafoam in the tank. Thoughts? __________________ 2006 roketa 200cc 1971 Yamaha xs650 2x 1980 xs650, 1 is a café, other is a chopper/brat 1972 Honda xl250 2x early 90's Honda rf600 parts bikes more mc junk laying around.
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