Carb Leak after workshop visit

Hi there. I just got my bike back from the shop after having a few things done and theres a leak out of carb #2 that I didnt have before. Before I pull the carbs out , I thought I should check that that was the best course of action.

disclaimer: I am a mechanical noob so please forgive any improper descriptions and general noob-ness.

Originally , I had a blown starter motor which is why I put the bike in the shop.
The bike had a decent oil leak from the valve cover , so I asked them to change the gasket and they adjusted the valves. I dont think the shop has anything to do with this problem though as I doubt they touched the carbs beyond the fuel line.

there was also a small leak after the petcock from a fuel line leak , just in front of the inline air filter a previous owner had installed (It didnt look to be from a worn-out petcock diaphragm) so I asked the shop to change the line out.
they changed the line but didn't replace the fuel filter.

It took a while for the parts to come in so the bike was sitting for about ten days I reckon? Probably long enough to have an affect on a ring etc.

When I first got the bike back it was fine , but the power seemed a little low . I took it out for a small ride ( about 2 hours ) and the next day rode it to work and around town. I filled up that night and she was running kinda rough , but I thought maybe it was new fuel , or maybe now that there was no fuel filter it was a little gunky.

The next morning still rough , but after 30 mins or so of riding she came right.

This morning I took it out and It was running rough again ( sounds like 3 cyclinders and not smooth like normal ) and when I stopped at my destination I realised fuel was pissing out of carb #2.
I took the bike home for a closer look , and discovered the fuel leaking out of a gap between the Carb and the Carb air intake rubber boot. The Boot is not sitting on the carb properly and fuel is coming from the gap.
There are no clamps on the boot for carb #2 or #3 but #1 and #4 have their clamps all good.

My question is ; If I re-seat the air intake boot ( from air filter to carb ) and put the clamp on will this fix the problem , or is the leak likely to be elsewhere and will petrol build up and come out the overflow instead?

I tried to tap the top and sides of the carb to see If Could jiggle the needle/float thing but it didnt seem to do anything. After reading on this site about other peoples carb problems , it seems that %90 of the time the solution is to take your carbs to church , but as I am a noob and the directions were complicated , id worry id mess it up more than fix it. Is there any other approach I could try before rebuilding the whole thing?
Can I take the #2 carb cap off and spray carb cleaner in there? Or change out some o-ring on that one carb only ?


Thanks for your help ! This site is a great resource.

1982 XJ750

 

Send your carbs to hogfiddles and they will be done up perfectly if you're not confident taking them on yourself

 

There are no short cuts and mechanics in a can (spray cleaner) won’t fix 36 year old worn out parts.

It sounds like you read the Bible for Church and yes it IS intimidating to those who doubt their mechanical abilities.

So the easy fix is - stop doubting your skill level. As long as you have other means of transportation, get yourself dressed up and go to Church son!

It can be scary doing something you have never done before, but patience, good organizational habits, lots of notes/digital pics, the correct tools (JIS and ‘custom ground’ flat head screwdrivers), correct parts (XJ4Ever) and questions that can be answered here is all you need. Keep asking questions until you get the answer that you understand - don’t be afraid of sounding dumb, I do it all the time.

You got this JTP!

P.S. did you read this?
https://www.xjbikes.com/forums/threads/the-information-overload-hour.27544/
and for reference:
https://www.xjbikes.com/forums/threads/in-the-church-of-clean.14692/

 

Okay first pull the plugs what color are they black and sooty rich, white to grey lean if they are brown or tan is where you want to be. How old are the plugs , might want to put in a fresh set gapped correctly . If the clamp is missing from the boot , get a proper replacement (xj4ever has them) . A hot shot is Another thing you can try tip.the tank up pull the fuel line off petcock , drain the fuel bowls. Take a meat injector(syringe) fill with a mixture of Berrymans B12 and acetone and squirt into the fuel line , will take several shots . Let sit for 30 minutes , drain the float bowls , reconnect fuel line out petcock to PRI and start bike up , take out for a short ride see if it clears up.

 

Ok great thanks!

 

@Stumplifter

Ha thanks man , inspirational! Unfortunatley this is my only way around at the moment , but I saw this link :

clean-your-own-carbs-the-whole-9-yards-by-rick-massey.2908/

and figured I can get through the first part , or lower cleaning ok , and leave the topside stuff alone well enough.

float fix here seems to help out without cracking them right open too , so i'm crossing my fingers.

xj650-carburetor-float-bowl-needle-adjustment-flooding-carburetor-fix.114577/

and worst case they need to be out anyway , so might as well do that part.

 

ala

forums/threads/removing-carbs-the-easy-way.87177/

 

Rick's posts can always be trusted. He hasn't been around for a while, but his wisdom lives on!

 

Hi. So I pulled the carbs out (thanks again for the encouragement @Stumplifter ) , cleaned out the float bowls and put a fuel filter on.The problem of the leak is gone , and all cylinders sound to be running normal again.
However , I took a trip around the block and once she warmed up , her idle went up to about 5000 rpm and wouldn't come down. It kind of felt like the accelerator was stuck on , but the handle returned like normal . The choke and accelerator cable went back to where they were initially I think . I had a look at the boots in and out of the carb and there doesnt seem to be an airleak I can see , so Im not sure what I did differently putting it back together?
Can I locate then simply lower an Idle screw? Or is this symptomatic of a deeper problem?

also , all the drain screws on all 4 carbs are buggered , so if I need to utilise them to set a level etc , i'd most likely need to drill them out I think so would be stoked to avoid that.

 

Now look - you can't SEE an air leak, also, you really need those drain screws to work, so if it takes a whole day, get them shifted and working.
Things that have to be done to get these things to idle:
Float levels set and checked,
Carbs synced (all the butterflies set at the same point). I can do this visually (bench set) close enough to get a decent idle by using the progression holes as datum poiints.
All gaskets and joints airtight between thearbs and the engine.

Once these are done you should getinto the ballpark.

 

Ah I see ( or dont , as the case may be ) ... I thought Id spy a gap or crack etc. Ill bust it out again tomorrow , get those screws out and have another go.