Topic: Re: New Member with a question/Re: AHHHHH DAMMIT, I NEED HELP!

[raymond10078]

When you say, the advancer works like it should - what does "like it should" mean to you?

does the timing mark align properly were the revs are high?  Movement alone does mean that the advancer is completely advancing.  Without full advance, gas mileage will suck.

How are your plugs?  what color?  Black/sooty plugs will say fuel mixture is rich.

The wrong air filter will be too restrictive (even so-called Honda brands sold on ebay) will destroy gas mileage.

Is your running voltage correct?  Low voltage will mean poor spark.

Muffler's clogged up?  It is possible that critters moved in and died while in storage.  You could try pulling the  baffles and running it open for a short while - cleaning the baffles if needed.

Bearings, brakes - wrong rock.  There's no way that you can eat up 20 MPG on dragging brakes or bearings - without them overheating to a puddle of metal.

Sam is right - I'm not going to re-read all of the previous posts.  If you typed up one concise list of things you checked (and what "good" was, or did look like), then I would help more.  Sometimes you've got to "put in the effort" to get the best help from this forum.

In the end, everyone on this forum is going to try and talk you out of selling that bike - especially if you like it.  You've got something basic going on.

[Bob Wessner]

USA 1-UK 0.

Sam.

USA 2 - UK 0. You forgot about 1776.  Though you gave it another good whack in 1812. 

[Sam Green Racing]

I gave it a good whack a few weeks ago when we tried to regain control of the US but you moved my post to the humor section (should that be spelled HUMOUR)

BOB 3- Sam 0.

Sam.

[raymond10078]

I had some down time, and did go back a re-read the past posts.  Based on the past posts, I still go back to three things:

- air filter.  You didn't want to mess with it because the prior owner said it was a recent replacement.  I've personally had experience (and others have, too) with ebay filters, claiming to be Honda OEM, that are too restrictive - they are crap - and they can cause what you've experienced.  A Honda filter (from a dealer) I would trust, or a K&N.  I went the K&N route.

- clogged mufflers/baffles

- timing not advancing fully.

All three items you can address personally. 

I'd hate to see you go, and give up on your ride.  You mentioned reliability - what you have now should be extremely reliable.  You're only complaint seems to be your gas mileage. 

[fuwad84]

OK! so we may have a clue in our otherwise cold, yet frustrating case. Yanked out sparkplug 1 and 4 to inspect em and what do ya know completely covered in a thick layer of black soot, just like the old plugs. Which means its running super, duper rich. I should note up to this point that this type of soot is very similar to the more powered appearing kind that seems to be collecting inside my mufflers.

I may not know much about motorcycles, but I do know even with a tiny scooter, running it just a little richer will kill MPG. So the 'ol gal may just have a reprieve after all...assuming I can get this resolved.

[raymond10078]

Ok - so now we have a solid clue.

I'd still replace the air filter.  http://cgi.ebay.com/ebaymotors/KN-K-N-AIR-Filter-HONDA-CB-750-HONDAMATIC-1976-1978-/230674828418?pt=Motorcycles_Parts_Accessories&hash=item35b54a8c82

It doesn't sound like you have a lot of carb experience or capability - true?  You could check the float settings externally (easy) - since if they are set high, you'll get too much fuel.  The 77/78 float height setting is different than the 76, and different than other cb750's, so . . . maybe they set them too high?  I can take a pic (later) of how to check, and then you can compare my settings to yours.

I would think it safe to assume that your carbs, when rebuilt, re-used the original jets, so jetting should not be an issue here.

I'll chime in again as I stew on this - hopefully others will, too.

[fuwad84]

OK people, here's a new conundrum for ya. Take it back to the shop mech., he tells me that it needs 4 new needle jet sets, exceedingly rare parts as I would later find out. It's Honda part number 16012-393-014 and I can't find these things for #$%*, does anyone know where I could get such parts...or after market carburetors that would work well with my bike.

[raymond10078]

It's too bad we can't talk to your mechanic.  All four needles and jets bad?  Sounds fishy to me.  I'd have thought that he sets the floats wrong, or something generic like that.

You may have better luck posting this question on one of the non-Hondamatic forum pages, since we all have them, and the "general community" may have sources that us "A" owners don't know about.

[raymond10078]

The only option that comes to mind is to start shopping for another set of carbs.  I've seen them for very cheap.  Just searched ebay - not that cheap right now.  If you have patience, the price will drop.

[MidnightLamp]

  I can't imagine them being bad either.

I would normally suggest opening the carbs, but the PD carbs can be a big pain to work with. I would check to make sure that the needles are clean and jets are clean as well. I have pulled out old carb sets and had the needles be perfectly fine, just sometimes a little crusty with gas residue. IF you find out that it's the carbs, I do have a set I'd sell.

[madmtnmotors]

Yeah, hard to imagine. My carbs (78' 750K) are pushing 60,000 miles with the original main jet needles and seats. Runs like a top (38 to 44 mpg). I think he needs a new mechanic, or at least a second opinion.

[raymond10078]

I posted a question on your behalf:

http://forums.sohc4.net/index.php?topic=97692.0

and we're all thinking your mechanic is wrong, or there is some miscommunication going on . . . .

Don't give up!

[fuwad84]

Hey Kandertech thank you very much.

[grcamna2]

  Carefully check out the condition of the inside of your fuel tank;if it has rust or ANY bits of foreign particles in there it will certainly be clogging your jets & keeping your needles & seats from closing when they should.I would also check your floats.
TAKE THOSE CARBS OFF OF THERE YOUR SELF & SEND IT TO ONE OF US HERE ON THIS FORUM; WE WILL GET THIS SORTED OUT AS FAR AS THAT GOES.
Sorry....I think somebody may volunteer to have a look at them & then your mileage will be MUCH improved !

[Danno]

+1