86 FJ 1200 pilot jet diameter

[Dr. Jay]

Hi Gang,

Because I ride way to infrequently, my 86 periodically gets gummed up pilot jets even though I use Stabil in the tank.  Years ago, a good friend cleared them up using numbered micro drill bits to remove the crud only, not enlarge the jets. I think the way he did it was by starting very small and going to bigger and bigger bits untill he started to show clean brass in the bore of the jet, but I'm not sure.  Anyway I am the proud owner of a new $3.00 set of micro drill bits and wonder if anyone knows what the actual bore diameter of my piolot jets is so I can start somewhere close to what I am trying to get them cleaned up to.  If you have a new or clean pilot jet and a set of number drill bits just letting me know the actual diameter of the bit that fits perfectly would be a big help. Or, perhaps someone knows how to translate the 86 pilot jet number to an inch or millimeter diameter. If I remember correctly he just spun the drill with his fingers to get the crystalized varnish out. I know I could order new jets at about $5.00 each but I'm cheap so help would be appreciated.
Thanks in advance,
Jay

[FJmonkey]

I clean them by soaking them in carb cleaner and then chase them out with a nylon bristle. Then I give them a good blast with the cleaner again. I'm a cheap bastard too.

[racerrad8]

Go to harbor freight and buy a ultrasonic cleaner.

I have never seen a drill bit small enough for a pilot jet.

Randy - RPM

[baldy3853]

What can I say I'm a cheap bastard too.

Is that why u photo shopped the ugh boots
out of your profile picture

[Dr. Jay]

Thanks for the input so far. The ultrasonic cleaner sounds interesting. Could you give some details on what solution to use, how long for and any tips to make it  most effective? The drill bits I got go down to fifteen thousandths !! of an inch. I didn't know any were affordable and readily available untill my friend used his to clean my pilot jets out several years ago.

[WestOzXJR]

.....if anyone knows what the actual bore diameter of my piolot jets is so I can start somewhere close to what I am trying to get them cleaned up to.  If you have a new or clean pilot jet and a set of number drill bits just letting me know the actual diameter of the bit that fits perfectly....

What number/size pilot is it? The standard pilot you have may not be a 40 that mine had, I believe many 1200's may indeed have 37.5's (someone will correct me I'm wrong about that).

I run drilled (pilot and main) jets in one set of FJ carbs... A # 78 drill bit (.016"/.4064mm) goes through a 40 pilot jet,  A # 77 (.018"/.4572mm) will remove material.

That is the answer to your question however, using a drill bit to clean them is not really advisable. The size of the (Mikuni) jet does not refer specifically to an actual diameter it refers to a flow rate and I can assure you through experimentation that a few scratches down the bore of the jet will make a marked difference in flow rate performance AND there's a BIG difference between a .016" hole and an .018" hole.

[FJmonkey]

Is that why u photo shopped the ugh boots
out of your profile picture

Nope, that's cuz I was a forgetful bastard. Kept my feet warm....

[56 CHEVY]

... using a drill bit to clean them is not really advisable. The size of the (Mikuni) jet does not refer specifically to an actual diameter it refers to a flow rate and I can assure you through experimentation that a few scratches down the bore of the jet will make a marked difference in flow rate performance AND there's a BIG difference between a .016" hole and an .018" hole.

[/quote]

Exactly what I was thinking. I was ALWAYS told "Never use a drill in a jet". Even if all you want to do is clean out the crud.

[Dr. Jay]

Hi Again Guys,
I checked out the reviews on the Harbour Freight ultrasonic cleaner and folks have not had much luck with it for cleaning really plugged up carb jets. So the question remains, if I don't use a drill bit and they are litterally plugged solid where soaking them in carb cleaner won't work, what do I need to do to get running ? Bite the bullet and buy new jets, or is there an effective method of  cleaning plugged-solid with varnish pilot jets? I'm sure with our wonderful ethanol gas today other forum members have run into the same problem.
Thanks again for the input so far.

[FJmonkey]

Hi Again Guys,
I checked out the reviews on the Harbour Freight ultrasonic cleaner and folks have not had much luck with it for cleaning really plugged up carb jets. So the question remains, if I don't use a drill bit and they are litterally plugged solid where soaking them in carb cleaner won't work, what do I need to do to get running ? Bite the bullet and buy new jets, or is there an effective method of  cleaning plugged-solid with varnish pilot jets? I'm sure with our wonderful ethanol gas today other forum members have run into the same problem.
Thanks again for the input so far.

Use a nylon bristle from a scrub brush. The nylon will not alter the size of the jet.

[Travis398]

I would clean it out with one of the small bits by hand and think nothing of it, and if you have stock jets you would probably benefit from making it a little bigger.

[andyb]

I use near-boiling hot water in an ultrasonic denture cleaner, actually   The solvent is a small squirt of dish soap.  If that doesn't get them clean, it's up to you, is saving the money worth the amount of time you'll spend fighting them?

[baldy3853]

For all the stuffing about u have done
for $3.70 ea  you could of purchased the
Four u need from Randy and fixed the problem!
Baldy

[RichBaker]

I bought my last set of pilots from a local dealer.... made some calls to see who had 'em, rode over and paid $10 for 4.  Had them installed and the FJ back on the road the next day.

[FJmonkey]

I bought my last set of pilots from a local dealer.... made some calls to see who had 'em, rode over and paid $10 for 4.  Had them installed and the FJ back on the road the next day.

Rich, you don't understand!!! What we need is Goldberg Machine designed for cleaning out clogged jets...... Remember the old Mouse Trap game?