Strange rubber plugs in bottom of pilot jet

[ddeford]

Hey guys,

I have a 92 Kat 600 that I purchased a while back that I've been slowly converting into a street fighter.

I pulled apart the carbs to give them a good cleaning and found these rubber plugs in the bottom of the pilot jets. I figured that they were supposed to be there (having never disassembled Kat carbs before) so I left them there when I re-assembled the carbs.

After thinking about it, and since I can't seem to get it to idle consistently, I started to wonder if they actually do belong there or if one of the previous owners put it back together incorrectly. The guy I purchased it from knew absolutely nothing about any kind of engine repair/maintenance.

The plugs do not fit snugly into the holes either.

Since I have it all assembled, I opted to do a 3D model of the rubber stopper thing rather than disassemble my carbs again to get a picture:



I've been working on motorcycles since I was 7 years old and I've never seen anything blocking the pilot (or any other) jet before.

Anyone else ever seen this? Maybe Suzuki put these in the pilot screw holes and when a PO added a jet kit he/she put them into the pilot jet hole instead??

Thanks,

Dan

[05RedKat600]

If they don't fit snug, get new ones. They are supposed to be there!

[Kreylyn]

Hey guys,

I have a 92 Kat 600 that I purchased a while back that I've been slowly converting into a street fighter.

I pulled apart the carbs to give them a good cleaning and found these rubber plugs in the bottom of the pilot jets. I figured that they were supposed to be there (having never disassembled Kat carbs before) so I left them there when I re-assembled the carbs.

After thinking about it, and since I can't seem to get it to idle consistently, I started to wonder if they actually do belong there or if one of the previous owners put it back together incorrectly. The guy I purchased it from knew absolutely nothing about any kind of engine repair/maintenance.

The plugs do not fit snugly into the holes either.

Since I have it all assembled, I opted to do a 3D model of the rubber stopper thing rather than disassemble my carbs again to get a picture:



I've been working on motorcycles since I was 7 years old and I've never seen anything blocking the pilot (or any other) jet before.

Anyone else ever seen this? Maybe Suzuki put these in the pilot screw holes and when a PO added a jet kit he/she put them into the pilot jet hole instead??

Thanks,

Dan

Nice rendering...

Yes, they belong. They are to allow access for removal of the jet, but the fuel is supposed to be metered through the main jet, to the emulsion tube area, then cross over through a port to the pilot jet under the plug. No plug = way too much fuel and flooding out issues for the pilot circuit.

Krey

[steves]

If they don't fit snugly anymore, they are worn out, get new ones.

[ddeford]

Cool. Thanks for the quick replies. This is a great forum!

Nice rendering...

Yes, they belong. They are to allow access for removal of the jet, but the fuel is supposed to be metered through the main jet, to the emulsion tube area, then cross over through a port to the pilot jet under the plug. No plug = way too much fuel and flooding out issues for the pilot circuit.

Krey

Thanks .... So it goes without saying that loose plug = inconsistent idle.

[Kreylyn]

Thanks .... So it goes without saying that loose plug = inconsistent idle.

Yes, it can directly effect the idle.

krey

[blitz2190]

Hmm hey krey did the 93 750 have these as mine did not didn't think anything of it becuase most carbs i work on don't have them

[ddeford]

I just ordered new plugs.

In case anyone is looking for a place to buy them in the future, here's a link:
http://www.suzukipartshouse.com/home...90001/09490025

It's labeled as #50 on the schematic. Or the part number is: 13357-34C00

Just under $30 with shipping.

[Kreylyn]

Hmm hey krey did the 93 750 have these as mine did not didn't think anything of it becuase most carbs i work on don't have them

They are used on the 90-97 600s, and the 89-97 750s. I'm sure Arsenic can confirm, but pretty sure they are not on the 88, 89 600s, and I know they are not on the post kats 98-06 models.

Krey

[arsenic]

Funny thing about them, the 89-97 Kat 750 uses BST36SS carbs and 32.5 pilots and they do have them. The 88-89 GSXR 750 uses BST36SS carbs and 32.5 pilots and does not have them. I have no clue why they are there, but they are.

[stretched600]

I had issues with cylinders filling up with gas and turns out the little rubber plug was the culprit. IDK why but they are a big deal...

[blitz2190]

Funny thing about them, the 89-97 Kat 750 uses BST36SS carbs and 32.5 pilots and they do have them. The 88-89 GSXR 750 uses BST36SS carbs and 32.5 pilots and does not have them. I have no clue why they are there, but they are.

Just a thought but could it be because of the more agressive cams in the gsxr and without them the kat runs to rich?

[arsenic]

That would be a "guess". I don't do that.

[marcusdweaver]

Im not sure if this thread is dead or not but i have these in my 91 600 however they are only in the middle 2 carbs. none in carbs 1 and 4. should they be in all the carbs or just the middle 2?

[Kreylyn]

Im not sure if this thread is dead or not but i have these in my 91 600 however they are only in the middle 2 carbs. none in carbs 1 and 4. should they be in all the carbs or just the middle 2?

All of the carbs. If the ones you do have do not seal well and will fall out on their own when turned upside down, replace them as well.

Also... make sure that isn't what happend to the others and they are not left blocking the vent ports in the "top" of the carbs... like the set I just opened did.

Krey