FOOLISH QUESTION. AT FIRST GLANCE

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F 18 Driver

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Hello everyone,

This might sound foolish at first but let me complete my thoughts before you draw any conclusions

Disassembling the carburetors found the main jets to be at 155

Here's the foolishness, what screwdriver are you using to remove the pilot jets…

The screwdrivers that I have accumulated over the years for carburetor work, which are not flared are not long enough to reach into the block jet assembly which will allow pilot jet removal.

I don't want to use a cheap tool and take the chance of stripping the brass slot of the pilot jet.

My over cautious behavior/question is a result, of experience with other carburetors where the pilot jet are tough to remove due to the ethanol in gas that has dried over years of nonuse and formed a very tight bond

I was hoping somebody who has done the carburetors a few times, I might be able to to help…

For those of you who may or may not be aware of this issue most screwdrivers are flared and the orifice in the block jet assembly will not accommodate such a tool

Thank you in advance.

F-18 driver
 
I use hollow ground gunsmith screwdrivers. You are right to be wary, if you screw it up, any if the carb jets can be tough to get out, you only get one chance. Good support under the carb, make sure the blade is engaged, firm downward pressure and hopefully you get the snap of a jet unscrewing for the first time in years.
 
No big deal if you break the slot, a reverse drill bit will usually pull it out before you can drill through the pilot jet.

1696461450438.png
Harbor Freight $8.49
https://www.harborfreight.com/left-hand-drill-bit-set-13-piece-61686.html
PB Blaster works well for fasteners needing removal, it's what my machinist uses. Kroil is also good but pricey.
1696510615489.png

https://www.harborfreight.com/pb-pe...MIn-eWtvregQMVIp1aBR2zuwvBEAQYBCABEgJ-VfD_BwE
https://www.amazon.com/Penetrating-...ocphy=9011924&hvtargid=pla-548961577674&psc=1
1696510731706.png
 
Last edited:
Hi everyone,

I searched and found a few 3/16 screwdriver that were not flared and were able to perform removal of pilot jet.

First, channel lock 3/16 blue handle… Didn't really like the quality of the tool.

Next, I kept looking around and on my way back from the airport. I saw a harbor freight and decided to stop in.

There, I found a set of Doyle 6 piece screwdriver set 2 of which were 3/16 not flared fit perfectly better quality tool than the channel lock.

I recommend the Doyle set as I believe it's higher-quality

F-18 driver
 
Hello everyone,

This might sound foolish at first but let me complete my thoughts before you draw any conclusions

Disassembling the carburetors found the main jets to be at 155

Here's the foolishness, what screwdriver are you using to remove the pilot jets…

The screwdrivers that I have accumulated over the years for carburetor work, which are not flared are not long enough to reach into the block jet assembly which will allow pilot jet removal.

I don't want to use a cheap tool and take the chance of stripping the brass slot of the pilot jet.

My over cautious behavior/question is a result, of experience with other carburetors where the pilot jet are tough to remove due to the ethanol in gas that has dried over years of nonuse and formed a very tight bond

I was hoping somebody who has done the carburetors a few times, I might be able to to help…

For those of you who may or may not be aware of this issue most screwdrivers are flared and the orifice in the block jet assembly will not accommodate such a tool

Thank you in advance.

F-18 driver
Your questions are not foolish......your experience with this problem is obvious and your cautious approach is well justified. There are dozens of posts on here about how to remove the jets when people that think they can do carb work failed. You'll get the jets out easily if you follow these guys' tricks with your experience and apparent skill.
 
I haven’t pulled the carbs apart on my Max yet, but when working on the Mikunis from the older XS and XJ bikes I have found using a tiny “pencil” type butane torch and heating the body around the pilot will help soften the grunge and also expand the area around the jet to aid in removal.
 
I haven’t pulled the carbs apart on my Max yet, but when working on the Mikunis from the older XS and XJ bikes I have found using a tiny “pencil” type butane torch and heating the body around the pilot will help soften the grunge and also expand the area around the jet to aid in removal.
Be careful with any heat source. The metal will appear intact, until it suddenly collapses, with the use of excess heat. Potmetal doesn't have a very high melting point anyway.

The search feature is your friend. A thread for those with knackered pilot jets or other ones.

https://www.vmaxforum.net/threads/h...-a-broken-screwdriver-slot.49066/#post-489249
1696780868226.png1696780893966.png

The guys who are the professional mechanics will agree with me, it's better to replace the parts with OEM new ones, than to count on re-using the jets, the rubber plugs, and the jet block gaskets. Yes, if you're exceedingly-careful, you might be able to remove the jet block without tearing the gasket underneath. However, if you replace it, you have a newly-gasketed surface and should get many years of use out of it. The rubber plugs often become deteriorated after decades in a gasoline bath; they harden, they fall-apart when you're trying to remove them, and they play 'hide-and-seek' when you drop one under your workspace, never to be seen again. Spend the few bucks, you'll be glad you did.

Item #36
Needle valve assembly
1FK-14190-15-00
$16.40 Replace all four. This is what keeps your gas where it should be and where it shouldn't be.

Disclosure: I have used K&L needle valve assemblies, they are cheaper than OEM. However, I've said, "Use OEM," so that's the part # and price I included here. I normally don't replace the needle valve seat, if your bike has 40,000+ miles on it, you might want to consider replacing the neelde valve and seat together. There is a kit including the cap for after you press-out the old seat, and insert the new one.


Item #10
O-Ring
93210-03119-00
$4.78 Buy a couple, like the rubber plugs for the jet block holes, these have the habit of playing 'hide-and-seek' with you. These are the tiny O-rings under the Constant-Velocity (CV) Caps, easily-lost if you don't-know to look-for them and to save them. IF you're not tearing-down your carburetors to tank them, like I'm doing, you don't have to remove the CV caps and you won't lose them. However, for the minimal price of these, you'll have a replacement when yours run-away from you. Same carburetor fiche link.

Item #22
Pilot screw set
12R-14105-00-00
$6.51 These are the screws under the CV carburetor caps. It's a good idea to have a couple of these around should you need them, as a prior bike owner may-have buggered yours, and that's why he sold it to you so-cheap, because he never fixed it, and it runs like-it. "It just-needs a set of plugs, man!" Same carburetor fiche link.

OK, back-to the carburetor jet block. Let's say that you've managed to remove the four float bowls. Did you have a tough time trying to get the float bowl cover past the float bowl vent pipes? That's whay I gave some input about having to loosen the brackets holding the carbs in two pairs, so you could remove the rubber gas lines, and replace 'em. You do not have to break the carbs down into for separate units! You just have to give yourself enough wiggle-room to get the float bowls off. Then you can remove the jet blocks.

About removing the jet blocks: they're held by two phillips screws. Remove the screws. Before you try to remove the jet blocks, grab your trusty mechanic's pick, the one that looks like what the cute dental hygenist uses on you during your semi-annual teeth cleanings. Dentures? 'Never-mind!'

Us the mechanic's pick to carefully separate the gasket from the carb body. I usually try to leave the gasket attached to the carb jet block. Work the edge of the pick entirely-around the jet block gasket, below it actually, with the pick tip resting on the carb body. You can see the gasket nearly the whole way around the jet block, and as you use the pick, you should feel the jet block release its bond to the carb body and the gasket. If the jet block detaches from the gasket, carefully-remove the jet block. Be sure that you aren't pulling up on the jet block, with one-half of the gasket stuck to the jet block, and one-half stuck to the carb body. You want to try and save the gaskets.

If the jet block gaskets tear or delaminate, that's why you've bought four new ones. Clean the surfaces, use the new gaskets. On the re-assembly use the new gaskets and save the old gaskets for spares if you were successful in removing the old jet block gaskets, intact.

OK, now we have the jet block on the workbench and you were successful in removing the main bleed pipes. Maybe you were successful in removing two of the pilot jets, but when you tried the third and fourth, you felt the screwdriver slip, and when you turned upside-down the jet block and tapped it on the workbench, all you were able to see were gold slivers from a fragmented pilot jet. No pilot jet came-out! Now, you did use some type of carb cleaner solvent, before trying to unscrew all-four, yes?

OK, so only two came-out. Spray more carburetor cleaner into those holes, let 'em soak. Go to your local hardware store or Amazon, or Harbor Freight Left Hand Drill Bit Set, 13 Pc. $(8.49) and buy a set of left-hand twist drills. Regular drills have a right-hand twist, you're buying a set which turns in the direction that unscrews a screw, as you're drilling.

Carefully align the drill bit in the hole. I used a 9/64" drill bit. Be sure that you have your cordless drill set to -Reverse- and slowly pull the trigger. You don't need to bear-down with a lot of force, the jet is brass. Brass is soft. The bit should start to grab and drill. Use a slower drill speed, and less-force than if you were trying to drill a hole in steel plate. You should feel the bit working, and if you have a sensitive touch, you may-feel that suddenly the resistance of the drill working is much-easier. Stop drilling. Remove the drill. Invert the jet block, and tap it on the workbench, and you'll likely see the pilot jet and some shavings fall-out of the jet block. Your left-hand drill unscrewed the pilot jet as it was drilling the brass, and your problems are over. Use solvent and compressed air to blow-out the passgaeways. Use your new jets and new gaskets if you're keeping the bike.

You can also use this method on the pilot screw, the one under the bottom of the CV cap.
 
Potmetal is very tricky material to weld. Every time I've done it there's always surprises involved and it will give you no clues when it decides to melt to the ground.
 
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