Pilot jets?

been dealing with a hang idle issue. Idles fine till you touch the throttle then she hangs around 3000 then very slowly comes back down, sometimes. New manifold gaskets, rubber coated the rubber mounts. All new vacuum port caps. New vacuum line to peacock. Floats checked. Nothing fixes it. Went to get new pilot jets and they are discontinued. I'm a machinist so I'm just going to bump them up myself from 36.5 (.0143) to 40(.0157). My question is, how much is too much?

 

I would not mess with the jets--at least not yet. You have an air leak somewhere that is causing the hanging idle. It may very well be the seals around the throttle shaft that runs through all 4 carbs. At least that is a common cause. Someone will give you more details soon, but you can try a propane torch and blow some gas around the throttle seals while it is idling and see if you get a change in rpm's. If it idles fine initially, that tells me that the jets are ok. There is no return from drilling them, as as you already know they may be hard to replace. If anyone has them it would be Chacal (see upper right hand corner). It would also help to know what bike you have and if it is stock.

 

Did the whole propane, carb cleaner nothing changes the idle until I crack the throttle open then she hangs. Did it with the boots off the back so I could see if the slides were hanging up, throttle is snapping shut, choke plungers are down..........

It's an 85 XJ700 Maxim aircooled

 

just asking has your throttle cable been lubed lately? and is it routed properly>

 

I do not see a mention of new throttle shaft seals.

 

Valve clearances in spec and carbs synched?

 

Chagall has some jets, not sure if he has the ones for your bike though. Have you tried jetsrus.com I know they have a lot of different jets. I had a similar problem and it ended up being the enrichment jet in the float bowls.

 

Agree you do not have a jet problem have you done a proper bench synch . Need some info what is your idle set at? Can you adjust the idle with the adjustment knob? Are you running my least favorite PODS ? As has been asked have you replaced shaft seals? are your mixture screws set at 2.5 turns out?What does your plugs look like? Black and sooty? Sorry to ramble on but these are things I would look at.

 

That'd be Chacal.

 

Your absolutely right, didn't even notice that error.

 

Have you had the carbs off, disassembled and cleaned? I have the same bike and I did't get it running well until I did the carbs. I also had a leaking intake manifold gasket, but you have already replaced those. Unless you have a linkage problem I'm pretty sure you are sucking air somewhere,maybe the shaft seals. I'm assuming you have a stock bike.

 

Opened up pilots to 40's and new clamps on the manifold side. Bike runs perfect now. Wish I did one at a time then I would know what fixed it.

 

It's probably the new clamps. It should have run perfectly on the stock pilots.