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**JWSanders** · 11-04-2006, 09:23 PM

Welcome to the site!! You will find tons of information here.

You will definitely want to make sure all the carb passages are clean. In your case, go through the pilot circuit of the carbs. Also, make sure idle mix is correct and they are all synchronized. Proper syncing will smooth everything out at all RPM's.

The procedures for all of this are in the repairs and maintenance sections of the forum. Also, a search will yield tons of posts about the carbs. They are probably the most problematic area of these beasts.

It should pull pretty solidly with the pilot circuit from idle on up, but the mains kick in at around 4000 and you know when it happens!

I had to clean my carbs half a dozen times before I got them right.

Good luck and happy hunting!! After you get it right you will almost think the bike has a turbo on it from a dead stop!!

**MAXIMAN** · 11-04-2006, 10:06 PM

If you have air blow back you might have an intake valve sticking a little. More than likely just putting miles on it will free it up unless it's burnt. Try a little upper lube in your fuel like Seafoam. It might help free things up.

You might also want to run a compression test for diagnostics.

Secondly - the feeling of being "shot out of a cannon" at 5000 is pretty nomal for these bikes. If you look at any of the dynos posted here you'll see the power curves climb radically in the 4000 to 5000 range.

**Pat Kelly** · 11-04-2006, 10:26 PM

2 things that could account for abnormal feeling of accelleration could be:

a> spark advance mechanism sticking until sufficient RPM gets the weights to move or:

b> pilot jet or passage clogged in one or more carbs. I had this problem and found about the same symptoms as you describe

**Ken Talbot** · 11-05-2006, 02:52 AM

Dirty carbs and plugged low-speed ciruits. There really isn't any work-around for this. You need to get into the carbs and get them srucuplously clean. Follow that up with a good vacuum sync and colortuning and you'll be on your way. 'Normal;' would be strong pulling all the way from idle to redline.

**TADracer** · 11-05-2006, 08:46 AM

Welcome!

A good manual would be of great help for you.

If your bike has been sitting around for any period of time then I would seriously recommend taking the rack of carbs off and tearing them down for a good cleaning. Carbs on these bikes are a balancing act and are a real source of curseing when not clean and tuned but a thing of true harmony and beauty when working well.

Clean them individually so that you do not mix up parts. While you have them apart check to see if you have the right jets. If your 79 special is stock, mains should be 137.5 and pilot jets should be 42.5. While you have the carbs apart, be sure to remove and clean the emulsion tubes. Spray cans of carb cleaner are OK but a good soak in carb cleaner (remove all rubber/plastic parts first) and then blowing out all the passages with air is better.

Adjust and syncronize and your bike will make you feel like you must hold on from off idle all the way up through red line.

**chopwatchagot** · 11-05-2006, 10:33 AM

This is your first bike? Dude, you got BALLS!

**skids** · 11-05-2006, 11:04 AM

You can add, c> bad exhaust system with either leaky pipes or crapped-out baffle.

Originally posted by Pat Kelly
2 things that could account for abnormal feeling of accelleration could be:

a> spark advance mechanism sticking until sufficient RPM gets the weights to move or:

b> pilot jet or passage clogged in one or more carbs. I had this problem and found about the same symptoms as you describe

**prometheus578** · 11-05-2006, 11:11 AM

"Not trying to be disagreeable..."

But I must disagree.

but a good soak in carb cleaner (remove all rubber/plastic parts first) and then blowing out all the passages with air is better

As it's his first bike, and probably his first set o' carbs, I would caution against totally disassembling them. Carbs don't need a complete teardown unless they're really honked up, which isn't the case as she runs reasonably well. Spray can carb cleaner should handle everything.
Remove the float bowl and clean the little jet on the bottom, the one that feeds the tube, that feeds the enrichener circuit.
Remove the main and pilot jets.
In the intake side o' the carb there are three 'jet' holes. Spray into one, and the spray should come out the main jet tower. Spray onto the other, and it should come out the pilot jet tower and out the small holes by the butterfly plate, especially the pilot screw hole at the top.
The third hole is for the enrichener circuit(Choke, for you automotive types)
Remove the pilot screw from the top o' the carb(engine side) It has a spring, a washer and a little o'ring, too. Make sure all passages are clean. When reassembling, the spring goes on the screw, then the washer, then the O' ring last.
Do not use compressed air to clean passages unless the float bowl is removed, as you'll compress and crush the floats. Damage can also be done to the vacuum diaphram at the top with compressed air. Do not put nails in your air gun and chase the cat around the garage. (too many people on this site get sidetracked with frivolous pursuits when cleaning carbs... which is why they have to do it over many times.)
Keep the carbs bolted together. No need to remove carbs from the bank. (Money can be removed from the bank and sent to me, as my advice is never free.)
Adjust the float height as per what Manual says. (Don't listen to Manual's brother, Jose, as he's an idiot)
Hook a fuel source to the carbs and 'bench test' them for leaks before reinstalling them on the bike.
Pat's comments about a sticking vacuum advance are valid, too

**skids** · 11-05-2006, 06:42 PM

If you are going to clean them without disassembly, here is a write-up on the subject.

http://home.comcast.net/~sidhansen/carbs/spraycarb.htm

And here is a schematic on the 78/79 carbs to help you figure out where all of the "gumout" is going.

http://home.comcast.net/~sidhansen/carbs/carbs.gif

**NemisusDM** · 11-05-2006, 08:43 PM

WOW! Thanks for all the info guys.....

The first time I got to 5k rpm I ended up in the passenger seat. I was ready for her after that....lol

I got the bike a couple of weeks ago and it did come with the Clymer manual. I've been supplementing the manual with this site. The bike was not used for about 2 years so I've been going over everything.

I did take the carbs apart and dip cleaned them. I also adjusted the floats to 28mm and replaced a sticking valve needle. I did not vac. sync. nor did I color tune. I have the needles adjusted to 1 1/4 turns like in the manual and I sort of sync'ed them by micrometer. ( ordered a colortune and sync. gauge set )

I do have a leaking exhaust gasket ( new set on it's way) and I'll order a compression guage along with a valve adjusting tool.

**TADracer** · 11-06-2006, 01:16 PM

No sweat here!

Originally posted by prometheus578
But I must disagree.

No problem, Prometheus, I am certainly not that thin skinned. If this is Nemisus's first attempt, perhaps a less invasive approach is recommended.

I just know my bike was not used very much for a few years and when I started riding regularly again, I chased carb problems around with spray cans until I cursed the thing. So I spent a leisurely afternoon with a few beers soaking and reassembling and all the carb problems vanished.

**NemisusDM** · 12-24-2006, 10:51 PM

Hello,
I did the dip clean initially so, I tried the spray type first before taking things apart again.
I used carb cleaner spray first and I did have 2 partially clogged air pilot jets. I continued to spray every intake on the carbs till they all overflowed equally. After all was dry I followed with SeaFoam Deep Creep Spray till that overflowed through all intake holes also.
Learned that a dry foam pod filter will release small peices of foam and clog the carb. All new filters and freshly oiled.
I then added SeaFoam to a full tank and noticed a huge difference after about 10 miles of riding.
I wonder if the lack of lead in the gasoline is the cause of the problem since, it mainly benefits the valves. I may need to start filling up at the airport or use SeaFoam in every tank ( one can of SeaFoam should last about 4 tank fulls).

Thanks for all the help.

**chopwatchagot** · 12-24-2006, 11:09 PM

No need to get the GAS discussion going again and no need to fill up at the airport. It'll run fine on pump gas if it is tuned properly. If it's not tuned properly it won't run well on anything. If you dipped the carbs without taking them COMPLETELY apart and taking ALL the rubber pieces out you most certainly ruined the important little o-rings hidden deep beneath the pilot air screws and probably the seals on the ends of the butterfly shafts. You have to really work to get those butterflies disassembled without ruining the little phillips screws that hold them in but that's the only way to get the seals out.

**goldcoastguy001** · 12-25-2006, 04:45 AM

Welcome to the site, im rather new here too but i tell you these guys will make you feel welcome and a part of the furniture in no time....lol...... rough idle? bad performance at low revs?...Hmmm sounds familiar to mine when i first got it running.....

I'd agree that you need to clean th pilot jet.....the small jet next to the big main jet in the centre of the tower between the float bowls......its has a reaaalllllly small hole thats is very easily blocked I'd beat $$$ that this is clogged up.....clean it out and i think you'll be supprised at how much this jet affects low range revs/performance.....no doubt you'll find out how "easy" (trying to be realllly sarcastic) it is to take the carbs off....so I'd make sure you give the carbs a good clean and double then triple clean everything so you can minimize having to take them off tooo many times to get it right....Take it slow and do it right.....if you get stuck...stop and consult these guys they'll save you a heaps of time.....

would be cool to post some pics of the bike.....have fun....

Cheers!

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power curve or carbs?

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