Forum Donations
Search
VTF Google Search
 Click Here

Xv500 will not start with "choke"

  • Advertisement

Post a reply

Re: Xv500 will not start with "choke"

PostAuthor: rchawaii » Sun Apr 25, 2021 3:33 pm

Do you have the filter in and the plastic box cover on it when you start?(The one inside the frame?) Have you completely checked the floats?

Choke problem indicates to me something is up at the carbs.

While it is running, did you spray carb cleaner around all of the connections to see if you have vacuum leaks?


Also I dont know why someone would change the jets unless they tried a single carb setup.

You're starting from someone elses missteps. But I would ensure factory jets are in place and start from there.
My Ride is a 1983 XV 500 :usa:
User avatar
rchawaii
Senior Membership
Senior Membership
 
Posts: 305
Images: 12
Joined: Tue Sep 16, 2008 7:32 pm
Location: Dallas, N.C. Flag
Bike year & model: 1983 Yamaha Virago XV500
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Tue Apr 27, 2021 3:29 am

rchawaii wrote:Do you have the filter in and the plastic box cover on it when you start?(The one inside the frame?) Have you completely checked the floats?

Choke problem indicates to me something is up at the carbs.

While it is running, did you spray carb cleaner around all of the connections to see if you have vacuum leaks?


Also I dont know why someone would change the jets unless they tried a single carb setup.

You're starting from someone elses missteps. But I would ensure factory jets are in place and start from there.




Hi , wont start at all now, just turns over and over, air filter in or out , cover on or off, makes no differance, will not start. On the times it has started I have sprayed carb cleaner all around connections ,no changes. I am getting new main jets this weekend (hopefully) When It does run ,and up to working temp it runs fine, its like its missing choke, Ive had carbs apart many times, blown through with 100psi compressed air, all jets/holes/passages/orifices blow through with carb cleaner, choke plungers stripped/cleaned/rebuilt, float levels checked, new gaskets ,"O" rings, float needle valve replaced and new seat (rebuild kit), new pilot air jet screws, compression good, sparks good, checked coil windings, all good, obviously I have missed/overlooked something please tell me what, I'm getting hacked off with this, I've been at it on and off for months and still no further forward, would the slightly wrong size main jets stop it starting, I thought they controlled high throttle openings , not starting? Pilot air screws set at 2 turns from soft seat.

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: rchawaii » Tue Apr 27, 2021 8:13 am

While you had the carbs apart, did you look at the immulsion tubes?

https://i.ebayimg.com/images/g/1Y8AAOSw ... s-l500.jpg

If they're blocked, it can cause issues. Having the wrong jets can effect many things.

You say you're getting spark, and fuel, assuming oxygen is present, it should attempt to start. Have you checked to see if the petcock is functioning properly? Since someone else has messed with it, its plausible they messed with it as well?

Petcock should be set to prime for a couple minutes, then on to start.

Also the start circuit is tied in to the right handle controls, Has that right control switch been looked at? I know on mine if I press the start button a certain way, lights come on , sometimes they do not, meaning no starting power. Something worthy of checking as well.

No Leaks ?
My Ride is a 1983 XV 500 :usa:
User avatar
rchawaii
Senior Membership
Senior Membership
 
Posts: 305
Images: 12
Joined: Tue Sep 16, 2008 7:32 pm
Location: Dallas, N.C. Flag
Bike year & model: 1983 Yamaha Virago XV500
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Tue Apr 27, 2021 9:41 am

rchawaii wrote:While you had the carbs apart, did you look at the immulsion tubes?

https://i.ebayimg.com/images/g/1Y8AAOSw ... s-l500.jpg

If they're blocked, it can cause issues. Having the wrong jets can effect many things.

You say you're getting spark, and fuel, assuming oxygen is present, it should attempt to start. Have you checked to see if the petcock is functioning properly? Since someone else has messed with it, its plausible they messed with it as well?

Petcock should be set to prime for a couple minutes, then on to start.

Also the start circuit is tied in to the right handle controls, Has that right control switch been looked at? I know on mine if I press the start button a certain way, lights come on , sometimes they do not, meaning no starting power. Something worthy of checking as well.

No Leaks ?

Hi thanks for reply, a few things I should have mentioned, carb rebuild kit (gaskets /"O" rings / pilot air screw /float valve and seat, I will also post some pics, at present the fuel tank is off being painted, I have rigged up a gravity fuel feed so that's not the problem, though the fuel pump is not being used at this time it does work. Fuel is getting into cylinders, I don't know if in the right amount of fuel/air mix, looking at plugs from time to time sometimes they are wet sometimes only damp. Emulsion tubes are clear. Starter button works fine, no issues. When it does start and gets up to working temp it's fine, definitely needs "choke" (enricher) to warm up. In my life time I have owned about 20 motorcycles from 50cc to750cc some of them 2 strokes some 4 and never had this much trouble with all of them put together. I consider myself a mechanically competent amateur not professional, we all have lots to learn (me especially) my last bike was a ZR7 with carb trouble but I sorted it and was running sweet and pulled like a train, PS can anyone tell me how to post pics? PPS new main jets arriving for weekend, can anyone think of anything else or tell me where I've gone wrong or what I've missed, I suppose It could be a blocked passage/hole/ orifice within the carb body, it would be unlikely but not impossible having had carbs off many times and loads of carb cleaner through them and 100psi compressed air (once)

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Wed Apr 28, 2021 1:46 pm

I know why at the moment it won't start, when I checked the ignition coils I got the wires connected to the wrong coils, what an idiot I am, just waiting for new main jets, then try to start again

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: rchawaii » Wed Apr 28, 2021 3:22 pm

Space hopper wrote:I know why at the moment it won't start, when I checked the ignition coils I got the wires connected to the wrong coils, what an idiot I am, just waiting for new main jets, then try to start again


Meh, we've all been there at one time or another.
My Ride is a 1983 XV 500 :usa:
User avatar
rchawaii
Senior Membership
Senior Membership
 
Posts: 305
Images: 12
Joined: Tue Sep 16, 2008 7:32 pm
Location: Dallas, N.C. Flag
Bike year & model: 1983 Yamaha Virago XV500
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Mon May 03, 2021 10:22 am

New main jets in, still won't start from cold, give it a sniff of carb cleaner and it starts , when warmed up runs sweet, tick over good, throttle responsive , everything works from electrics to brakes, you name it, it works, as supposed to, the only thing is starting from cold! any ideas?

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: rchawaii » Mon May 03, 2021 11:31 am

Where are you spraying the carb cleaner?
My Ride is a 1983 XV 500 :usa:
User avatar
rchawaii
Senior Membership
Senior Membership
 
Posts: 305
Images: 12
Joined: Tue Sep 16, 2008 7:32 pm
Location: Dallas, N.C. Flag
Bike year & model: 1983 Yamaha Virago XV500
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Mon May 03, 2021 5:08 pm

Carb cleaner sprayed into bellmouths, this is after trying to start with airfilter installed,cover on and using varying amounts of choke, I have sprayed around outside of carbs (when engine running) to check for vacuum leaks, no leaks. When engine warmed up runs sweet, tried tiny amount of choke while running,but still cold, and it kills it, any thoughts? It sounds like choke mechanism problem but I have stripped choke bodys and plungers and all seems to be working as they should, carbs 3 day's ago completely stripped (again) all passages/holes/orifices spray through cleanly, all jets clear (new mains of correct size), vacuum plungers and diaphragms all good(and air cut off valve/diaphragm) clearly I am missing something, could still be carbs I suppose, if not carbs then what? I checked tappets a couple of weeks ago, they were very slightly tight , might be worthwhile checking again now its been running.Thanks for any help. Ps compression good (150) ,timing correct

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male

Re: Xv500 will not start with "choke"

PostAuthor: Space hopper » Sun May 09, 2021 3:17 pm

Now does start with full choke, but only rear cylinder, if I put my hand over front bellmouth it will fire, I think it means front carb too lean? Any ideas?

Space hopper
Junior Membership
Junior Membership
 
Posts: 18
Joined: Sun Mar 28, 2021 4:20 am
Location: England Flag
Bike year & model: 1983 xv500 virago
Sex: Male


Previous

Post a reply


  • Advertisement

Return to Yamaha Virago XV500

Who is online

Registered users: No registered users