Carburetor Leaking - O-ring replacement vs Jets vs Bowl vs Float

Follow up thread to previously posting about valve cover gasket attachment. Finished the valve cover gasket replacement on rear (3 & 4 i believe) and it went great. Ended up painting a very thin line of Permatex gasket adhesive and it remained in place perfectly for the reattachment. However, after putting everything back together I now have a fuel leak after starting the bike. I can see fuel dripping fairly rapidly when viewing from the left side of the bike, at what appears to be between the two carbs (I can't see exactly). It is below the air filter box and I say this to inform that this is NOT a gas tank leak. It did stop leaking after shutting off the bike. I should inform that this bike has sat covered in a heated/cooled garage for years and I am now bringing her back to life. I expected some gaskets to be dry and brittle. I have looked for info/videos on how to remove the lower portion of the air box to view the top of the rear carbs but I cannot find any. I know this could be many different things including floats, jets, bowls, gaskets, and/or O-rings. I've read where O-rings are known to dry up and need replacing but I can't find any info on how to do this. I've also read where bikes that have sat for awhile get "re-lubed" and these leaks can disappear but only temporarily. Thanks for any ideas or suggestions here.

 

Sorry, but time to pull the carbs as an assembly. Replace the fuel cross over tube o-rings and you might as well do the float bowl o-rings as well. Pretty much time to go thru the carbs.

Not a fun job, but not hard. Just tedious and needs attention to detail. The first time feels daunting, but it's easy.

You can source viton o-rings in the correct sizes if you don't want to buy "kits". I source my stuff individually for pennies on the dollar.

 

Ugh.. not what I wanted to hear. Would you believe the local Honda shop I bought this bike from 29 years ago won't even touch it because it's "too old"!?!?
I could only expect that this is what I need to do. I am really worried about pulling off the carbs but even more worried about reinstalling them. Thanks for your reply. Should I go OEM from Honda for rebuild kits x 2?

 

From your response, it sounds like the best thing to do is:

Pull the carbs (as a unit, do not remove the plenum). Package nicely. Send out to be completely refurbished. There a a few very qualified people to do this.

Buy new rubber insulators.

While you are waiting for your carbs, read up on carb installation (which is actually pretty easy with new boots) and detail your engine.

If you want to proceed on your own, then post progress with pictures. You will get help.

The OEM kits are STUPID EXPENSIVE. Spend your money elsewhere and get more for your buck.

 

i'd be pleased to go through your carbs, replace O-rings and float bowl gaskets, clean internally and externally, clean all jets, synch throttle plates, make adjustments, lube throttle shafts, lube choke plungers, and finally a 24 hour leak-test. also will inspect all parts and replace any that are worn out or damaged.

i have years and years of carb work experience and offer my service to members here and at the other place.

my work and your satisfaction are guaranteed !

please pm me for details.









if you want to try waiting for the O-rings and/or bowl gaskets to swell up and maybe seal again you'll need to keep fuel in the carbs for a day or two by hot-wiring to bypass fuel pump relay and activating the pump frequently (depending upon amount and speed of leaking).

 

^^^^^ Seriously consider this option. No real need to learn this skill, as you will likely never have to do it again.

He does very good work and his retired ass would likely appreciate the $$.

Win - Win.

 

Your trick about heating the intake boots with a hair dryer and using two small flathead screwdrivers to ease in the rear carburetors made this so much easier than anything else I tried. I would assume it's similar on a 750.

"When you go to press into the rear boots, you can take a small flat blade driver and help get the boot "started". Also heat them up with a heat gun and get them nice and soft. Helps so much!!!!"

Stubby, it'll actually probably be quicker and potentially cheaper to have them sent to Squirrel. In addition to knowing it was done right, another added benefit is that if there is something out of sorts that isn't obvious, he'll be able to see it right away whereas it may go unnoticed if you haven't been through these carburetors before. It's far from an impossible task, but it can be a real headscratcher.

 

You guys are awesome with all your suggestions. I love this site! Thank you all very much. Squirrel, I'm not keen on hot-wiring the bike for the fuel pump but I am planning on reattaching everything since I found the leak. We'll sees if it reseals up or not. I know the carbs should be looked at soon regardless if this self-corrects or not. I would LOVE to discuss the option of you performing your "magic" on the rebuild. Just let me figure out how to PM you! Colddevil, thanks for the suggestion on the hair dryer boot heat up. I will definitely make note of that! Will post info and possibly pic's as I delve into this.

 

Thanks for the help! Noted!

 

another thing that helps soften carb mounts is boiling them in water for a few minutes.

something that often helps seals swell up is to get the engine running up to the normal operating temperature.

 

don't bother reusing the old carb rubber boots. You can get them (non Oem) very cheaply. The first set have lasted 29 years so assume you have your moneys worth from them. Heating up the old ones is an exercise in frustration - it does work BUT the job becomes a lot harder.
Think of painting the garden yard fence with a toothbrush.... Its possible but not ideal - lol...

 

LOL! Yes, the old boots are the original's and 31 years old. I'll check into them and will talk to squirrel about this if/when he does the rebuild.

Thanks Pete!

 

Hot wiring the relay is almost a pre-requisite for this era of bikes. If my wife doesn't use her NC29 (1989) for a month then this is almost certainly needed. After a winters layup - i know before doing anything I'll be jumping the relay. Don't fight the tide - its easy and quick to do. Basically the fuel pump is crap at sucking and sometimes needs some help...

It only takes a few seconds - you will hear the pump work then after a few seconds slow right down - think tick,tick,tick,tick,tick going to tick---------tick-----------tick-----------tick.
The moment it does that the pump is primed.

 

https://www.ebay.com/itm/1982-86-HO...947097?hash=item2cff400699:g:fVAAAOSwApRd-QAu

This guy I was able to talk to, impressive. nuff-sed

This is what I bought for one bike that had a leak. I bought a second set and plan on doing the install soon. I bought insulator boots for this particular bike not too long ago along with the associated gasket kits from honda. I will re-use the boots but ordered new oem gasket kits for the four carburetors. One of those things like Captain said, "if your in there, you might as replace the gaskets etc." Its a tedious job, make sure you do it in a well lit/clean area and work on something where you can see an errant spring, o-ring that gets loose. I like a white towel high jacked from the linen closet. Just don't let your little missus see it or your gona be in the dog house. Take pictures as we have no lives and enjoy looking at this chit all most as much as porn.

 

Well here's the latest: Good News & Bad News! Reassembled gas tank, air box/filter and kept cowlings off to view for oil or gas leaks. Started bike and voila!~~~~~ Purred like a kitten. Good news? - you ask? NO LEAKS. No oil leak! No gas leak! Zero! ZIP!! Bad news? - you ask? Well.. after letting the bike idle for some time (probably 30 minutes or more) and listening to the sweetest sound, I went to check the blinkers. Left side, front and back? - Check! Right side front blinker? - Check! Right rear blinker! NEWP! And after about 5 fast blinks of the front blinker, she died! Went to start again and battery was almost dead. The infamous click, click, click sound of a dead battery. I'm thinking this is good news because I am hoping a stator or alternator replacement (whatever she uses?) should be a lot easier than a fuel or oil leak! Going to surf the VFRWorld website for similar posts about charging issues and will make a new post if I can't find what I'm looking for. Thanks again to all you that helped me here. I still may be pulling carbs before too long and sending to squirrel for rebuild but for now... NO LEAKS and running smooth. hahahahahahah

 

Some information for the OP which might be of help:
http://v4dreams.com/maintenance.html

 

no surprise that battery died as very little charging goes to battery at idle speed. be sure to check that you get about 55 AC volts from each leg of stator at about 5000 rpm.

good work gettin the leaks to stop.