First attempt to start: fuel streaming from carbs

[tejasmud]

Carbs that have been sitting for...., well if you don't know, need to come off anyways. Clean, dip, "do it to it"...

Rebuilt by the Suzuki Race Team, if they leak, they come off.

Old boots, rubbers, whatever they have ever been called, on either intake or airbox, if they are old hard and crusty? Yes, PITA. Replace them and it becomes less of a pain in the...........

Carbs rebuilt by a "Guy who knows...." should come off if they leak now.






Sometimes if they have just been put on and leak, after checking them, and there is a spill "give them the ole' tapper roo".... It works sometimes.


But, it doesn't always work. More than not here, yes, but I cleaned them.




Leaks like this usually happen if they have been just put on after cleaning, and I didn't check them first.

99.9% of the time, if they were checked first, no problems with leaks.

Still don't see the taboo...

Pull them babies, and be done with it.

 

[tkent02]

I wouldn't be as prone to try this move with an old crusty set of carbs that were most likely full of bad gas.

If that were the case I wouldn't even try to start it.

 

[81gs1100]

One thing no one seemed to mention and I recommend it to anyone rebuilding or trying to clean up a set of carbs....

Buy yourself a pop-off valve pump, its just a small hand held pump about the size of the Suzuki fork pump, that has a little gauge on it.

Before putting the bowls on turn the carbs upside down and spray a little WD-40 on and around each float needle and seat, make sure you get all around the base of the seat as well as it will show if the o-ring is bad.

Then just pump some air into the fuel inlet, the gauge will show that it is holding pressure, just slowly pump air and watch for little air bubbles around the seats or past the needles. You could continue pumping and watching the gauge till it builds enough pressure to pop-off a valve.

I faught a set of carbs and used the pump and found the o-rings were leaking causing my carbs to overflow. Now I will never put float bowls back on untill I test the needles and seats.

You can find them doing a search for "pop-off gauge for watercraft"
http://www.thefind.com/pets/info-pop-off-gauge

 

[Dreef1999]

Everyone???

I personally use a rubber mallet and whack more than tap. Worked just today when my number 1 carb was streaming gas.

On an aside it is a nice nice feeling when everything goes back together and it actually starts!

 

[Don-lo]

Yes, they sometimes hang up when they first fill with gas. A gentle tapping will usually fix it, if not then it's time to check deeper.

Before trying to start it, I would pull the spark plugs and spin the motor to make sure gas did not fill a cylinder.

 

[supersonictoys]

Quote:
Originally Posted by supersonictoys
I wouldn't be as prone to try this move with an old crusty set of carbs that were most likely full of bad gas.

If that were the case I wouldn't even try to start it.

I guess my own situation may have differed from yours. if you owned and operated a large motorcycle dismantling business and received maybe 3-5 bikes a week (every week)which needed to be checked out and these bikes had been stored away, some for a year, some for several years and you didn't know which ones had been drained or the length of storage or even why they were stored away in the first place you would be more prone to actually "try" and fire these bikes before ripping the carbs off and going through them all. otherwise you might find you would be rebuilding a set of carbs for a bike that was stored away with a dead hole or a smoker or even a find a bad tranny or a rod knock. as I said," if a bike came in that I knew had carbs that were most likely full of bad gas because they stunk to high heaven and had brown gravy in the tank and they were pooring gas all over the floor I would be less prone to try tapping on the carbs to jar loose a stuck needle and seat". tapping on them obviously isn't going to magically remove bad fuel gum and varnish build up that would stick a needle but we weren't talking about a set of carbs that were full of bad gas . the guy who started this post said these were carbs that were supposedly just gone through and rebuilt by a pro. I personally have had newly rebuilt carbs (rebuilt by me) that would for what ever reason over flow when first installed and tapping on them fixed the problem 100% without any further issues. maybe the float pin for some reason has a little drag inside the float when dry, maybe the sharp edge of a new needle in a new seat for some reason didn't move as freely as it should when the float is hanging all the way in the down position. for what ever reason, I see no reason for anyone to be afraid to tap on the carbs to check and see if it stops them from over flowing. if you nay sayers have lots of extra time on your hands are just itching for a project go ahead and pull them if you like.more power to you. I have tapped on carbs on literally hundreds of bikes over the past 25 years on everything from vintage one cylinder bmw R25's and triumph's tridents to RE5's ,water buffalo's and cbx's. and maybe 60-70% of the time they stop leaking. don't be so afraid of a new "100 year old" idea. LOL. you wont harm a thing

 

[rustybronco]

the guy who started this post said these were carbs that were supposedly just gone through and rebuilt by a pro.

That's what worries me.... did this "pro" even install the correct jetting need for his application?

A "pro" overhauled a set of carbs for a member of this board and installed the floats upside down. YMMV...

My cousin was a "PRO" at a auto dealership (and a cycle dealer also). my dad took his 84 suburban in to have the tranny fixed, they couldn't because they didn't have a trans mechanic.
he told the service advisor, "I understand what it's like finding good help, my nephew works here". yep that's him...

how about the carbs I just fixed on a cb750f... the "gentleman" (read pro) who overhauled and reinstalled them, said the carbs may need some tweeking... it wouldn't idle below 2.5k because all the pilots where screwed closed kool huh?

 

[supersonictoys]

(Quote)That's what worries me.... did this "pro" even install the correct jetting need for his application? (quote)
who said he even changed the jetting and what does jet size have to do with a carb leak? while your post does show that there are people out there claiming to be bike mechanics who clearly don't know what they are doing it offers no help for the guy who originally asked for help. instead it points out wacky, bizare and extreme examples of carb work done by obviously untrained, inexperienced individuals. your post above further strengthens my belief that having someone who posted this....

(Quote) I had forgotten why and how much I hate carburetors.

dive into a set of carbs that are leaking a bit of fuel isn't a good idea at all especially without first at least tapping on them to see if the leak stops. sounds like he may have had bad experiences with carbs in the past and it may not be his field of expertise. for those of you so quick to have an unwilling novice dive into something he is obviously uncomfortable and unfamiliar with, how about a novice drops by and has a go at giving you that vasectomy you have been considering?? anyway longitudinal probably isn't even following this post anymore and is probably out riding his bike which is where we should be.

 

[rustybronco]

http://www.thegsresources.com/_forum/showpost.php?p=1091548&postcount=1

(EMGO pods.)

http://www.thegsresources.com/_forum/showpost.php?p=1091748&postcount=14

willing to try fixing it?

if so, read on...

did you rap the side(s) of the carb(s) as you were asked?

what has been done other than the pods? exhaust changed? was it re-jetted?

and why do you think I asked about the jetting...

sounds like he may have had bad experiences with carbs in the past and it may not be his field of expertise. for those of you so quick to have an unwilling novice dive into something he is obviously uncomfortable and unfamiliar with,...

I did...

even had him stay for dinner.

 

[supersonictoys]

dont get it? are you the "pro" who worked on his carbs? is this him? is this you? is this your cousin? are you cleaning them with "gain laundry detergent" ?

 

[Longitudinal]

OK, several days away from GSR here, so here's the update:

Yes, I tried rapping/tapping/cajoling the float into floating. The carb had at some point begun to drip instead of streaming out fuel. It continued to do that, though. My friend came over and found that he had installed something wrong with the float on that carb. The carb still drips when the bike is parked on the side stand, but seems not to when parked on the center stand. It's kind of a heavy machine to drag up onto the center stand, but I will deal with that for now.

I also found that the PO or somebody had incorrectly wired the white and black/yellow coil wires. After straightening out those wires and reinstalling the carbs, the 750 fired up without too much cranking. My friend stayed to do some adjustment on the carbs. It needs more, but it does run.

I need to go back into the ignition and do the relay trick now that I have a running bike, and also check valve lash. I looked through the Clymer manual and was both pleased and disappointed to learn that this engine has a direct acting valvetrain, just like my VW junk. I like the directness and the simplicity of design, but I do not like the need for shims, having been hoping on the Suzuki that it would be a matter of turning adjustment screws on rockers. Eh, oh well. I assume that the shims aren't too hard to get.

So, it is running and in time to be my transportation to school. And I can finally give my impressions of the bike, which are mostly positive. I like the overall feel of it. It feels slightly large for my height, 5' 10". My arms are a little too straight for my taste, but I can live with that. It feels very positive in spite of desparately needing the new fork seals installed and new tires front and rear. It feels easy to balance, is mechanically quieter than the Nighthawk I had last summer and has a very pleasing exhaust note. It seems to take a long time to warm up; I am ten minutes into my ride before it will idle off the choke. The brakes seem to be more than adequate, and I really like having a hydraulic rear disc brake compared to the cable-pulled drum on my Nighthawk, which seemed to require frequent adjustment. I like this bike a lot so far. It's a much better fit for me than the Nighthawk 650 ('83 model, 16V and shaft drive) or the scooters I had been riding more recently.