pulling my hair out

ok, i did a very thorough cleaning of the carbs following ricks instructions, verified float levels using clear tube method, and bench synced, today i reinstalled the carbs and it went back to square one of when there's fuel it starts and revvs very high(around 8000rpm) and now i'm not getting fuel to the carbs from the tank, on any setting, prime reserve or on, no fuel, i'm so lost, pleas help me i know i need to clean the tank, but how, and how do i fix my carbs so it doesn't revv so high?

 

After cleaning the carbs, you'll likely have to sync the carbs as well. There are guides on here to walk you through that. First a bench sync (off the bike), then sync them while running the bike.

If you have to clean the tank, and you're not getting fuel to the carbs, it's possible you have something clogging the petcock inside the tank. If you disconnect the fuel line from the carbs and direct it to a gas canister, hit prime on the tank, it should come out and into the canister. If not, something's clogging the flow. I'd check the fuel line and inline fuel filter (if you have one), then the tank.

 

Try the star wheel while running? The big knob between carbs 2 and 3. Maybe its open just a wee bit too much??

 

It's very common to have the idle knob turned up way too far or to snag the throttle quadrant under the fins on the back of the head. An improperly seated throttle cable can cause it too.

Check the vacuum line for cracks, no vacuum no fuel, except: You should get fuel in PRI unless the inlet pipe in the tank is plugged. Unhook the line (and put a rag under it) to check. If no fuel even on PRI, open the gas cap. If fuel suddenly flows you have a plugged gas cap vent.

 

thanks fitz, tried the star wheel after you mentioned it, no luck, in either direction, as for the gas tank, i'm not getting fuel with cap open or closed, i'm thinking i might have a serious vacuum leak in the intake boots. but i'm not sure how to diagnose or fix that problem. i did bench sync the carbs and i triple checked the float levels using the clear tube method before i put the carbs back on today, i'm hoping this girl is worth the money i'm putting into her

 

Boy I wish I had a nickel for every time I've said THAT.

Have you ever checked my gallery? If you want to talk WORK, then it's the white bike. If you want to talk $$$ then we'll discuss the "Toxic Asset."

In both cases, it was well worth it. I've put over 7000 miles on my '81 since I put it back on the road, and it's definitely worth every dollar and every minute I sank into it (3X longer and tons more work than ever anticipated.)

I wouldn't trade either of them for an FZRX whatever.

 

i love the bike, when she was running i was riding her all over town, 500 bucks for a 650, couldn't beat the price, i just wish she was running again so i could start riding again

 

take the tank off & run a clear line to the carbs from a temp' tank, SEE that you are getting fuel down there.

 

To check for Vac Leaks:
Take an ulit propane torch and turn it up. With the bike running ( Might be real hard to hear a diff at 8k though.. ) take the torch and put it over the boots on each carb. If it revvs higher, that means a leak in that boot.

Super easy check!!
And yes, invest in clear fuel lines
-Chris

 

The first time I did my carbs the same thing happened to me.It turned out to be the throttle hanging up on one of the metal clamps that are on the rubber carb boots.It wasn't even sticking by much but enough to make the thing race as soon as it started up.I'd make absolutely sure your throttle is moving freely before you get too carried away.

 

ok, checked the throttle linkage today, its not hanging up anywhere, i still haven't tried a temp tank yet to verify getting fuel, i did realize however that i have a spare petcock for the fuel tank, so i'll test the petcock and i'll drain the tank so i can clean the rust out, any one know what the best way to clean it would be?

 

Carb cleaner?

 

Some people like to throw some stones in the tank, and swirl them around when it's empty. Knocks off any rust in there. I'd just flush it out with fuel, make sure you put a fuel filter on the line after you're done.

 

we had a BIG discussion about all the different methods from electrolysis to commercial products to an acid wash.

Do a forum search for "rust in my tank" or "how much rust is acceptable" and you'll get some lively reading.

Personally I prefer phosphoric acid (concrete cleaner) from the building supply (Lowes/Home Depot.)

Aquarium gravel was a BAD idea; I had a heck of a time getting it all back out.

 

Just letting you all know I'm still having problems, now I'm trying to ger the cheapest fix possible, how can I repair the intake boots? And what else could cause the bike to rev @ 8000 if the throttle quadrent isn't hanging up and the carbs are benched to card stock specs.

 

http://xjbikes.com/Forums/viewtopic/t=18757.html

 

Thanks SL, now I need a fix for the boots on the engine side

 

as far as i know - the only "fix" for those boots is to paint 'em up with RTV sealant or replace 'em - but i'd think long an hard about that since the mounting bolts are prone to breaking.

 

i've already pulled those bolts twice, each time i pulled the carbs....both times i pulled them i used wd40 on the bolts while i had it disassembled and let them soak....but i will try coating them in RTV....any specific type or just plain old RTV?

 

Look in my gallery. My boots are in really good shape but a PO smeared them with RTV. I tried to get the rtv off!

What I did was cut some 3/4 inch lengths from a mountain bike inner tube and stuck some RTV on the underside. The result looks much better than RTV (High temp if you can get it) alone.