Carb Gurus - Question on Choke (enrichment) passages

[Khibbs]

Hello all and I'm new Forum and still putting together a thread on the 1997 VFR that I recently purchased to document the restoration.  Only 15K miles on the clock but she needs to be totally gone through.  I bought her not running and after unclogging the fuel pump and soaking the jets she's a runner.  My current issues is that she's hard starting as the choke (on or off) doesn't seem to have much impact.  Wondering if I missed something in my carb clean I found THIS THREAD that mentions cleaning the "choke jets" or enrichments tubes.

 

The thread says that you need to use a thin wire that should meet some resistance (the clog) about 30mm deep and you should make sure you can feed the wire all the way into 55MM (first photo below from this from post). 

 

I've pulled the carbs again and I'm using the thinnest wire in my cleaning kit and can't get it to go any further than about 10mm. 

 

I then tried compressed air and in the photo I've attached I can hear air going through on carbs 1 &2.  When I slide the choke lever there is an audible change and the air comes out in the main carb bore that dumps into the cylinder.  I haven't been able to get the same for carbs 3&4 in the photo.

 

Any help or guidance for those who have more experience with these carbs or the choke enrichment tubes would be greatly appreciated and I'm happy to check anything and report back.

 

Cheers,

 

Khibbs     

 

 

 

[DannoXYZ]

you need stiffer smaller wire, piano or guitar wire.

be extremely careful, it can scrape off brass and change size of petrol passage

 

also better to have ultrasonic soak

 

and micro soda-blast all circuits after removing jets

 

cleaning jets is just first 5% of restoration job

[squirrelman]

12 minutes ago, squirrelman said:

thin STEEL wire .010"  no problem with enlarging the hole as fuel enrichment is metered by choke plunger.  ultrasonic if you have it.  initial blockage at 10 mm (not 30mm) is common (where fuel level sits and dries up ).  i've found that a pecking motion and alot of it will usually clear the tube. slip a close-fitting hose over the tube to check by sucking or blowing if it's clear.  if you can get only 2 or 3 open it's ok cuz the bike will start and warm up until no choke is needed. peck, peck, peck ! check fully clear tube to a depth of 35mm (not 55mm).

 idle jet isn't clear until you've poked it through.

[Khibbs]

Thanks for the advice guys.  I've been pecking away with my thin wire and I haven't broken through on any of the 4 yet.  When I put compressed air I can hear in going through on one of them but I feel like I've got a ways to go.

 

One site I found recommended 0.021 wire or a # 75 pin drill bit.  I'm considering ordering a few of those to help me get through the blockage with a the chuck that you can spin carefully by hand.

 

The choke jet cannot be removed, pressed in. Clean the hole through the center of it, clean with an 0.021 inch wire or a #75 pin drill.

 

I'll keep at it with the wire and let you know how I make out.  Thanks!

 

Khibbs

 

[Cogswell]

You may find some useful carb maintenance info on this website. Scroll down to #18 to find specifics on carb resto.

 

http://v4dreams.com/maintenance.html

[squirrelman]

22 hours ago, Khibbs said:

Thanks for the advice guys.  I've been pecking away with my thin wire and I haven't broken through on any of the 4 yet.  When I put compressed air I can hear in going through on one of them but I feel like I've got a ways to go.

 

One site I found recommended 0.021 wire or a # 75 pin drill bit.  I'm considering ordering a few of those to help me get through the blockage with a the chuck that you can spin carefully by hand.

 

The choke jet cannot be removed, pressed in. Clean the hole through the center of it, clean with an 0.021 inch wire or a #75 pin drill.

 

I'll keep at it with the wire and let you know how I make out.  Thanks!

 

Khibbs

 

 

you'd need to be careful not to break off that very thin drill in the hole.

[Khibbs]

Thanks squirrelman.

 

That is definitely a concern but I'm unsure besides soaking the entire carb assembly how to get the choke passages clear.  On all four of them it looks like the opening reduces down about 1cm down.  I've spent a lot of time picking with different diameter wires, a needle, and compressed air with no progress.  

 

From what I've read the passage should be 0.021 so I my plan is to check the opening when the # 75 drill bits arrive.  If they don't fix (which I'm sure they won't) I'm not sure what other options I have to open them up but I agree there is a definite risk with such a thin bit.

 

 

 

 

 

[squirrelman]

last step would be trying ultrasonic bath but that would require disassembling individual carbs from the airbox base and disconnecting alot of fiddly stuff.

[COS_VFR]

Since you have the carbs upside down on the bench, have you tried letting some carb cleaner soak the jets overnight? Maybe slip a short clear tube over the jet and fill it up with carb cleaner to give it a good soak.

[jefferson]

I second the above. I use carb cleaner in an aerosol can to fill the cap to a level that will cover the jets in order to soak them. Works well. You have to barely depress the nozzle as you want the liquid dribbling out rather than spraying hard.

[Khibbs]

Thanks for the suggestion of the soaking the carb cleaner in the choke tubes.  I did hit them a number of time and let it sit in the openings.

 

Having no luck with trying to poke any of the small wires or needle though the initial blockage, I reluctantly decided to try the micro drill that I ordered.  I got a 0.021 drill bit as that was the size that I found online and VERY carefully started gently twisting a turn or so in, and then back out.  Clearing with carb cleaner every other time.

 

After doing this 8-10 times I realized the drill was noticeably lower and with a very slight push downward it went through!   

 

I was able to do this on all four choke tubes and I'm extremely happy I was able to break through with this method.  It just seems strange that when you look into the tube there is a significant reduction in the opening about 1 cm down but everything I read said the opening should be .021 so I'm not planning on opening up any more unless anyone can confirm that it should be bigger.  

 

Thanks for all the guidance and on to the next step in the carb reconditioning process.

 

Khibbs