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Discussion Starter #1
Hello everyone.

I have a choke problem in Keihin V335 carburetors. Two mechanics have already died and I'm a little bit disappointed.
The case is as follows: carburetors adjusted, cleaned, installed. Choke, it works mechanically, i.e. the cable is working, the nozzles are extended, but it has no effect on the engine operation. You have to start the cold engine without choking and keep the rotation with the throttle. When the engine warms up, the attempt to engage the choke ends in the engine choking.
I will be grateful for any hint in the topic. Season is going to end up and I want to drive some kilometers in this year L
Thanks in advance,
Gregory
 

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hi welcome to the forum. I hope that you mean tried and not died. you also need better mechanic.
1. carbs not done correctly
2. choke pathways still blocked.
3. engine running too rich choke has no effect.
4. air leak in system or some other mechanical fault over riding the choke operation.
 

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Discussion Starter #3
Thank You for the interesting in this subject.

Yes, tired (an alive) and refuse to do something more with this.

According to Your suggestion:

  • carbs not done correctly – maybe, I’m cant be sure in 100%
  • choke pathways still blocked –it’s possible (I have to check it on the bike)
  • engine running too rich choke has no effect – let mi stop for a while: when engine catch right temperature it works properly. Still rotation, power etc. So, to rich fuel-air mixture a thing isn’t a reason.
  • air leak in system or some other mechanical fault over riding the choke operation. – yes. I don’t have a big experience with carburators and I’m trying to understand how this choke works.
  • During starting with choke: throttle is closed. Nozzles are opened (B)
  • Black line (C ) open a way from the engine to under the membrane.
  • Yellow line A is for what? Vacuum?
    52533
 

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Correct, yellow line is for vacuum.
 

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hi. now a question are those cabs yours or just a standard picture of a set. the answer will determine the next phase.

"how does the choke work" well it isn't really a choke. but a fuel enrichment device. a choke reduces the air flow via a flap this cuts the amount of air entering the carb making it run rich for starting.
these carbs don't have this but a plunger that allows more fuel into the engine via small ports when pulled out. it does the same job but in a completely different way.
so yes a air leak would effect how they work. so would the whole set up as the carbs are balanced precision instruments it takes very little to stop them operating and the reason a lot of issues are carb related.
 

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Circled is the starter circuit jet, starter pickup (enrichener, choke whatever you want to call it) This is the point of fuel pickup and supply when the choke plungers are extended. Your dead mechanics may have failed to clear this circuit (it extends further)
The jet is fixed, pressed in at factory, non removable and needs to be cleared in place. IIRC a .014 steel guitar string needs to enter about 1" or 1 1/4" straight down to assure the jet portion is clear. The string will be stopped by a carb body wall. The circuit then extends, angling within. Invisible, without access except to fluids and/or compressed air. Finally ends at the little hole where the choke plunger lives. The metering tip of the choke plunger, when pulled, opens the hole, allowing flow from the pickup jet. Choke plunger pic metering sections red for fuel, yellow for air.

hd2.JPG
litb1.jpg
 

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Discussion Starter #8
Picture is similar to my carbs. see attached pictures of my own carbs from the "mechanic" page. Before I will detach carbs from the bike, I need to know what I have to check, this is the reason why I put so many questions. Thank You for Your understanding
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Discussion Starter #10
I bought those bike a couple weeks ago. As previous owner said, that bike was registered as small bike (with less power) and he change the carburators for this one. I'm not a specialist with bikes. I bought this one GPZ500 and I can't say it's ex500 or er500 and also it's orygial carbs for my Kawasaki.
 

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AH. right this is why background information is so important. a photo of the bike would help. but it seems on face value you have the GPZ500s euro model (same as EX500) but the previous owner fitted it with a set of carbs from a ER these are restricted to 33bhp so might be the issue. also the ER model has emission control and air control the GPZ does not have. also could cause issues. take them off and clean out the original GPZ carbs and put them on the bike. then retry.

for the benefit of other members. I have seen this before where in Europe the GPZ/EX 50hp is too high a power output for learner riders who are restricted to 33bhp in order to lose 20hp they fit power reduction carbs and inlet plates. rather than buy a restricted bike (like the ER5) it always causes issues as the jets are way too small #105/ #25 or something like that and the flow rate of the carbs is around 30CFM instead of 38CFM plus you have to remove and plug the air recirculating ducts often forgotten when fitting to a bike that does not have them. .
 

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Discussion Starter #12
Vin of my bike is ex500D000723 '94. When I boght Kawasaki, bike working fine with choke. From day to day, choke worked worse and worse. It looked like this recently. Choke open, ignites. The turnover was around 1.5-2, instead of 4 as it was initially. Maneuvering the choke causes it to go out more and more often despite a slight warming up, we had to wait a long time and very carefully close. Sometimes moving the throttle caused that the suction "clicked" and the revs jumped to the correct, higher, but over time it only worked for a moment. It was the reason why GPZ go to the mechanic. I don't have old carbs
 

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Vin of my bike is ex500D000723 '94.
right so your bike engine is a gen 2 D model 1994 one of the first. in fact the 723rd gen 2 produced.
do you need it to be restricted for your licence. if no take out the restrictors and get a set of genuine GPZ500 carbs to put it back to 50hp then have some fun you are losing 30% of the bikes power as it is.
 

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Looks more like an engine serial number than a VIN number.
Nice number (y)
 

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Looks more like an engine serial number than a VIN number.
Nice number (y)
yeah your probably right most if not all start JKAEXV on the headstock. not that it matters at least he knows the engine is 94 gen 2 so no worries about gen 1 issues..... good catch.
 

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Discussion Starter #16 (Edited)
My driving license hasn't got any restriction, so I don’t have to worry about. But please, which model of the carbs I have to find to reach 50hp?

Issue is that does carbs not work properly on the choke, but I’m really appreciate any information about my bike.
 

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which carbs !! stock GPZ/EX500 ones. I will say it again your bike has the wrong carbs fitted. you may only seem to be having issues with the choke but I feel the problem is much deeper in the carbs themselves.
a lot depends on the work done to bike so far. we and you have no idea what this was. the only answer I can think of is going completely stock and removing the modifications. you say two mechanics have tried to sort it and given up so the issue is more than just the choke
 

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But please, which model of the carbs I have to find to reach 50hp?
Issue is that does carbs not work properly on the choke, but I’m really appreciate any information about my bike.
Here's a few pics of OEM, stock supplied USA market EX carbset. Basic tuning components 130 main, 35 pilot jet, N36N needles. What are in yours?
81-5.jpg
81-4.jpg
81-3.jpg
 

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Discussion Starter #19
At the very beginning, I would like to apologize to everyone who tries to help me to solve my problem. The model of the carburetors was given to me by my "mechanic" because I was away from home. It turned out that I have no idea where he got the numbers from, but the actual marking of the carburetors is G285.
I took out the carburetors from the motorcycle, everything cleaned, rinsed, blown out.
The suction nozzles work properly, because after moving the suction nozzle, while blowing compressed air into the nozzle from the float chamber, you can hear the air flow. I did't dissasembly any nozzles till now.
I have mounted the carburetors on the motorcycle and the effect is still the same.
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hi, no need to apologise it makes no difference to the outcome wrong carbs same problem nothings changed.
 
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