XJ HELL Part 2 Sigh........

Hello again, So I bought another lemon (knowingly)
Second XJ Ive owned. Fixed the first one with this forums help.
1982 XJ550 Everything is stock has 10,000 miles hasnt been on road since 89, very oily and dirty
When I bought it it wouldnt start wouldnt idle,choke almost redlines it.
Air filter soaked with oil (was ran on choke for 25 years w/no petcock vacuum hose, set to prime.)
Wouldnt start unless I blocked the airbox.
I replaced the throttle shaft seals (xj4ever) cause idle hangs bad, wouldnt start.
That fixed the starting issue starts perfect everytime, Idle still ape shit after warm.
Bought new intake boots they where badly rotted.
Cleaned carbs 4 times (At least the 30th time I've cleaned xj carbs), but Jets are still under brass plugs
So why is it that the choke makes it redline where as my XJ650 it purrs with just a slightly higher idle, that is haunting me.
Worst problem is that the idle won't come down after it warms up it sits at 3000-4000 and all over the place.I thought the throttle shaft seals would have fixed it.
When cold idling it very slowly drops and dies.
Runs lean if you ask me , slight sputter at low speed.
Oh yeah I vacuum Synced the Carbs and adjusted the butterflies as well.
Diaphragms are great looking.
I can no longer get the idle to race with propane or starting fluid as a leak finder around the carbs.
Carbs had a load of rust sentiment in bowls due to tank having some surface rust, flushed now its always good., Got new vacuum delete caps and tried ones off my 650.
Swapped gas tanks and vacuum lines.
Is it possible that tight valves would cause an idle to go from normal to crazy in 2 miles?
All 4 plugs look identical, kinda lean.
Clunk test passed with flying colors.

So what am I missing, damnit I know its something right in my face. Last bike after 5 months of valves, carb cleaning over and over , and every other thing preached on here it was just the main jets drilled out(on my 650).

I know this has to be obvious to someone....Choke redlines it, and idle hangs and sticks as it warms up.

Thank you .

 

Valve clearances.
And drill out the pilot screw plugs. You can't have cleaned the idle passages with those still in.
Once they are clean, set the pilot screws to 2 1/2 turns out as a baseline.

 

Thanks I'll go do it now.......Really

 

+1 what k-moe said.

Gary H.

 

K-moe you nailed it, thank you. I was thinking lean so I was looking for an air leak. not thinking fuel restriction. Now I can sell it. I bought the damn thing for 600 to flip it for a couple hundred profit but after 450 in parts I wont be profiting a penny, maybe even losing a bit.....Weeeeeee. Seriously Thank You though.

 

K-moe you nailed it, thank you. I was thinking lean so I was looking for an air leak. not thinking fuel restriction Thank You! Now I can sell it. I bought it for 600 to flip it for a quick little profit but after 450 in parts lucky if I don't lose money...Weeeee....Great bike, I swear this 550 is quicker than my 650, defiantly handles better. Thank you so much again.

 

OK spidey - what did you set them to out of interest.. My story..

After 6 months (OK not everyday of course) trying to start my Radian engined 550 (598 now) with BS32 FJ600 carbs (no success) I cleaned-up the old BS28s that I thought were toast and what do you know - A runner !!

But mine is also racing I think to about 4-5k (difficult to be precise as I didn't yet wire up the electronic rev counter). lots of cable slack so I think the butterflies are on teh idle stop but I will have to check. Slides all appear to be running free, diaphragm are good (no holes) intake rubbers cracked in parts but repaired so airtight. Pilot screws are set to 2.5. Carb intakes are currently 'free to air' so next move will be re-fit old 550 box rubbers (has FJ600 rubbers on now) and an air filter.

To be honest I'm still rather pleased in even runs at all after the BS32 episode. Could running carbs with open mouths make a big difference under no load?

When I first ran it (no cable - forgot!) it started and ran lumpy on choke. I the fiddled around trying to connect the cable then restarted and the racing started so maybe I got it jammed a bit open ?

Cheers

J

 

Use an unlit propane torch around the the throttle shaft seals. You may have a vacuum leak there. You could also have vacuum leaks at the inlet manifold gaskets. WHen you clened your carbs did you go to The Church of Clean? It may be wise to star your own thread for this problme, as having the same symptoms does not always lead to having the same solution.

 

A100 man
if your carbs race, after cleaning try adjusting the throttle cable at the grip. it was my experiance that it was so tight that it redlined on my first startup after rebuilding the carbs. PO must have tightened it up to keep it running thinking it was how to adjust Idle instead of using idle knob,or had to tighten it up to keep enough fuel going through it to keep the bike running.
and of course as suggested by K-Moe do a propane test and your own thread

 

Thanks chaps - a few things to try. If still troublesome will indeed start a fresh thread..
But still a runner eh - who'd have thought !