4-1 Header Pipe

[wllara]

My 78' suzuki gs 1000 has just the 4-1 header, besides sound or police, is there any problems that could come from just having the header pipe, back pressure issues, valves, anything. I know people cut pipes really short just wondering if im gonna run into any problems. Im watching a 4-2 on ebay right now, and at a local salvage yard there is a 4-1 for $150. What do you think

[Steve]

Other than the noise and public irritation issues that you already mentioned, your carbs WILL have to be re-jetted.

If you are also going to run individual pod air filters, you will have to change your jetting for them, too.

Note that not all 4-into-1 headers are loud. My son has one on his bike that even I like.

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[wllara]

Rejetted

From the stock jets 95 mains and 15 pilots i went to 102.5's and stayed the same on the pilots. Also I have the stock airbox but the PO cut the bottom of the air box out where the two holes are and its just a rectangular hole now. Also Im not sure where I should move the needle jet it was on the bottom groove. Im still working out some issues, any ideas of where I should move it. Also the air screw is out 2 turns and the fuel screw is out 1 turn. Im waiting on my fuel T joint to get here, I just ordered yesterday to give it another try. Any ideas let me know

[Steve]

You will have to do plug chops to be sure, but, to me, it does not seem that just going up three sizes on the mains is quite enough.

But please keep in mind that I am no expert in re-jetting, I am only trying to remember what I have seen others post.

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[havoK]

not my post, but curious what a "plug chop" is? new to the forum and trying to learn...thanks

[Steve]

not my post, but curious what a "plug chop" is? new to the forum and trying to learn...thanks

Remember back on September 30, when you had your first post about carb cleaning, and BassCliff offered you his Welcome Package? Did you read it? ALL of it?

OK, it's not on the welcome page, but on his website (which you should have bookmarked), take a look in the right column, about half way down, there is an article called Plug Chops - Highest RPM Methods. Click on that (or the link I just gave you) and read all about it.

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[wllara]

The advice I got on my first post

I'd go

Main 102.5
Pilot 15
Air screw - 1 1/2 -2
Fuel -7/8 -1

Bogging is generally a lean condition

Your fuel screws are waaay too far out - be careful and don't snap the tips off

So I went with the 102.5's and the screw andjustments as what was suggested. I will read over plug chops today, Im at work and the link is blocked.

[havoK]

went and read plug chops, thanks for the info...

[wllara]

Exhaust Update

I ve been doing alot of reading on Bass Cliff's site, plug chops, valve clearance, changing tires. But I recently ordered a Vance&Hines 4-1 drag exhaust, $95 shipped, cheaper than what I could find locally or otherwise. Now for my jetting would 102.5 mains be a good start, 15 pilots, and needle clip on the middle groove. Also the air box holes have been cut to a single rectangle. I have also read that there were two kinds of these exhaust one with a baffle and one without, Im not sure if this one has a baffle but I wouldnt mind it being loud. Should have the exhaust in sometime next week. So Jetting does it seem I would be close, needle jet was on the bottom groove when I first got the bike, I thought I read factory is on the middle one or the 3rd not sure. Thanks

[vernond]

gs1100 old school sidewinder

just in case anyone might be interested?? i have a gs1100 sidewinder exhaust by MTC eng!!! looks like a star header.. i have it posted for 175.00 plus shipping.. chrome like new,and mtc sticker on megaphone is really nice also... great pipe for the right bike
thanks my # is 918-277-1102 if interested or email me vernons9358@sbcglobal.net