Spring "start-up"

[Sidecar Bob]

I'm not all that smart but if there was fuel in the plenum and the float valves are good the carb to plenum seals pretty much have to be the next suspect.

[redglbx]

Personally Dave I’d level things up on the bench and put a test bottle of fluid on the rack and let it sit. Carefully watching for a leak and noting where it’s coming from. Originally on this I was thinking maybe a stuck float valve and you may have jarred it loose now if it stays dry, then it was probably a stuck valve which I would closely inspect all before reinstalling the rack.Did you use factory float valves ?

This could also still be a carb to plenum seal so you’ll really need to inspect things closely. One other possibility but kinda remote is that I had a plenum with porosity around the #1 carb mounting pad that would leak. A new plenum fixed my problem but I’ve never seen or heard of this before but my friend that owned this bike (76 Ltd) from new always complained about it’s poor running, so who knows. Let us know how it goes.

[Dirty Dave]

If I remember, all but one was stock.

I will try putting fluid through the rack. Sounds like fun. Way better than reinstalling and being
disappointed again.

Thanks guys.

[Sidecar Bob]

I've been thinking about this and had started to type a long description of how I figured out that my leaks were from the carb to plenum seals but then I remembered that I started a thread about it at the time
viewtopic.php?p=628588

That thread ends with me talking about looking for o-rings to use in place of the correct seals. Since the ones that failed came from a Randakk's kit and I knew he was very concerned about the reliability of his products I sent him an email to let him know, just for his information and not expecting or asking for them to still be covered 7 years after I bought the kit.
He replied that one of his suppliers (since fired) had substituted the wrong rubber in a batch of parts around the time I'd bought the kit and that he was sending me replacements. As of last November the replacements were still working perfectly; Assuming they are still OK by the time the snow finally melts this will be 10 years.
BTW, Randakk asked me not to discuss him sending replacements for 7 year old parts on the open forum at the time due to concerns that some people might start asking for replacements for parts that had not failed but I assume that it will be OK to talk about this many years after he sold the business and retired.

[redglbx]

Bob, I had the same experience with the current owners where I had replaced the plenum seal twice on my dime and called them to complain. They sent me a new “verified” kit to help me out only for me to discover that it was actually porosity. I called them to let them know about my find and they just told me not to worry about it. Good people !

[Dirty Dave]

Thanks for the info.

One step at a time. Having fun.
Every time I play with the carbs I end up putting in another Helicoil.

[redglbx]

Yepper Dave , that happens to all of us I believe ,,particularly if like on my oe carbs they had a zipper on them and i constantly had them open to work on them. They were problematic to say the least.

I have theoe carbs out on the bench even though I’ve been running my highly modified 1100’s which work great, but while I still have my faculties about how they work I’m thinking it might be wise to just set them up ,, bag them back up and put them back into storage if I need them. I’m thinking I’m gonna just helicoil all the bowl screws just because. We’ll see… the oe 1000 carbs we’re running pretty good when I removed them but the 1100’s that I’ve highly modded are much, much better.

Can’t wait to hear you tell us about yours running and enjoying it !

[Sidecar Bob]

FWIW, I had stripped most of the float bowl screws over the years and replaced them with #6 SAE. When I replaced those carb to plenum seals I smartened up and bought some helicoils to do it right.
I guess they are probably OK but I haven't needed to remove any of the bowls since.

[Dirty Dave]

Can’t wait to hear you tell us about yours running and enjoying it !

It's a love/hate relationship. I guess I've kept it all these years because I like wrenching for the
most part. It runs so well when it does.

OTOH I started up the Valkyrie & Z900 yesterday. Five months down and they started up
with the first jab of the starter. Nothing wrong with that.

[redglbx]

Yepper Dave ! I understand the love/hate thing with these,,, when I bought my 76 new in Oct of 76 I really wanted an LTD but Honda was only giving 1 to each dealer and all the dealers in my area were taking bids on theirs with most at over 5k so that was a no-go.

So they were selling their yellow 76’s at steep discounts because they just weren’t selling them but I really disliked the yellow and wanted the red. So the dealer I was working with was owned by a guy and his father that I went to school with and after about 6mo’s of back & forth we finally came to an agreement.

So I went and picked it up, I was a really happy dude ! I got almost a mile down the road before the stator failed,,, should’ve taken that hint ! The bike never ran good but over the years we found things that improved it but it was never truly a great runner, just figured that was the way it was. When I got my LTD in like 1998 or so (basket case) and put it all together it was such a magical running machine it drove me to go after my red bike to figure out why it ran so poorly and about 15-20yrs or so ago I found that the timing marks on the flywheel were off with the t2 mark about 6deg off from the t1 mark. They are quite magical when they run right !

Once I corrected that my red bike was almost as nice a running bike as my LTD, love riding it although I haven’t ridden it now for several years because of back problems, hoping to be able to stretch her legs maybe this summer !

I understand the starting thing , I had an 86 Sei and a 2014 FJr that were both injected, just turn the key, push the button and ride ! On my older Honda’s I’ve found that turning the petcock on (full tank of gas) and opening the gas cap and letting them sit that way for 10-15min. usually results in an easier startup. When I get done with a ride I always turn the petcock off and run it as dry as I can which seems to help. Good luck !

[dartman1962]

It sounds more like a float valve issue to me.
You said as soon as you turned the petcock on it just died, then you had more fuel on top of what was already in the carbs, that caused fuel out of the exhaust.
That is your main supply.
Your jets just supply fuel to be metered by the system
That’s my .02 worth.
Once you have it figured, do as suggested & what you have always done!

[Dirty Dave]

While poking around the carbs I found some funky jet O-rings so figure they all need replacing.
Since they're out may as well do more exploring.

Losing some vacuum now for some reason. Will run a terrible bottle of Vodka I've been wanting to
get rid of when all has been gone through to look for leaks. Smells better than gas on the garage floor.

BTW, I always liked the look of the 76 yellow Wings. Ha!

[cfairweather]

In my humble opinion, the most likely source of fuel in the plenum is a leaky float valve and/or misadjusted floats. The next likely source is the plenum seal (the two lower fuel seals of the plenum) and the u-ring seals where the carbs mate to the the plenum. Sometimes the float valve will get stuck in one place and you can tap on the side of the carbs to resolve the issue.

[Dirty Dave]

Carbs are disassembled and seem clean as they were stored drained. All needles move freely on the
floats but who knows what they were like before I pulled them apart.

I paid close attention to float height last time but will recheck. Condition of rubber O-rings
is suspect so plenum seals will be checked. Main plenum seal was replaced 2 years back.

Will let y'all know when I do. Not in a crazy hurry.

[cfairweather]

I know some will disagree with me, but the float level height is not adequate to set these floats. I quit measuring and only use clear tubes to set them. There is a lot to getting the floats right on these carbs. You have to make sure the float is able to open the valve before the bowl gets too low on fuel and you have to make sure it closes just before the level gets to the lowest edge. The geometry of the float sometimes has to be slightly adjusted for these two important things to occur. You also have to adjust the wires on the needle in most cases.

Turn the carb set upside down and get them at eye level so you can see the needle move as you slowly raise the float. The needle should start moving BEFORE the float gets to the top of the tower. Then use clear tubes and check the levels using 70% rubbing alcohol. I use an electric fuel pump and stick the intake hose in the bottle of alcohol. If you have one carb level that is perfect (at the lower edge), use that carb as the model for the others.
I will try and fully document this process in the near future.