1980 G wont idle.

[Lbrown311]

aren't the carbs the same for early and the same for late models respectively? or are there differences in the styles of the early and late from standard to special? I thought there were just two styles of carbs. 78-79 and 80-81. I am new so I could be mistaken.

[crazy steve]

The carbs are the same basic unit for the two types, but there is minor differences in how they're jetted between models...

[cywelchjr]

The carbs are the same basic unit for the two types, but there is minor differences in how they're jetted between models...

And the metering needles for the standard and special are different at least on the later carbs. I believe the dynajet kit works around that though and that could be a good thing as special needles can be had but the standard ones are pretty much unobtainium.

[natemoen]

Wish I could delete my posts

[XSTrey11]

Well s***, Got my new pilot jets in the mail today and I ordered 42.5 but once I compared it to my old ones they're not the same. I think my old ones are size 45. So...do I need to return them or just stick the 42.5 in there and call it A-O-Good?

[bikerphil]

42.5 is the stock size, you should be fine. I'm not sure of what/if any intake or exhaust mods you have.

[XSTrey11]

42.5 is the stock size, you should be fine. I'm not sure of what/if any intake or exhaust mods you have.

I don't know about intake but the exhaust is different its just drag pipes. (not that I know what difference it makes)

[bikerphil]

I don't know about intake but the exhaust is different its just drag pipes. (not that I know what difference it makes)

These motors like some back pressure on the exhaust, so if your drag pipes have no restriction at all, that might present a problem.

[XSTrey11]

These motors like some back pressure on the exhaust, so if your drag pipes have no restriction at all, that might present a problem.

Haven't got a clue what that means. It's times like these I wish I could know more about the bike.

[natemoen]

Haven't got a clue what that means. It's times like these I wish I could know more about the bike.

Take some pictures of the pipes, if you can get some looking down the outlet of the pipes as well. also shine a flashlight down the pipe and see if you see anything in there, and try and describe it.

[DGXSER]

Generally speaking all exhaust systems have some form of baffles in them, mufflers. These present flow restriction for the exhaust gases and also tend to deaden the sound of the combustion process. This flow restriction causes pressure on the exhaust system, since it is holding the exhaust gases back, it is often referred to as back pressure.

Often times you hear some cars or bikes that sound like your standing next to the space shuttle taking off they are so loud. The exhaust system has had the baffles or mufflers removed altogether or at least greatly diminished. Drag racing applications will often remove the mufflers completely, on mine I have a Y fitting in the exhaust with covers I remove to let the exhaust bypass the mufflers for drag strip performance.

The engines on these bikes were tuned for best performance with the back pressure of a muffler/baffles in place. Very few people have ever had success tuning the carbs to work with no mufflers or baffles in place. You referred to your pipes as Drag Pipes, which would imply no muffler / baffles, no back pressure.

[crazy steve]

These motors like some back pressure on the exhaust, so if your drag pipes have no restriction at all, that might present a problem.

What Phil is saying is that completely 'open' exhaust (usually referred to as 'drag pipes') have no restriction/obstruction to exhaust gas flow such as mufflers or baffles, and very few street-operated motors run well with them (besides the fact that these are illegal). The XS is certainly one that doesn't run well with them. They do produce the most power at the top of the RPM scale (great if you're going drag racing, hence the name), but at the cost of power losses everywhere else. Few owners ride at full throttle all the time...

It also makes jetting the carbs much more difficult; poor low and mid range performance is pretty typical.

[DGXSER]

I should clarify that I meant I have that Y connector on the exhaust for my car that is set up for street use and drag racing.

[XSTrey11]

Well I suspect that I'll find they don't have any kind of baffles. Is this and issue I'll be able to put off until I can afford to correct it or should I avoid riding the bike until I can change the exhaust? Also, I'll get out there and look at it and try and take some pictures here in a few minutes.

[XSTrey11]

Because the tip is curved outward I cannot see into the exhaust at all.