'79 GS1000 baseline help

[Throttlejock]

Just picked this bike up last week and it feels much slower than it should, basically empty on acceleration. It's gone 33k miles so far, 300 in the last 3 years, and doesn't appear to have been well maintained. Carbs are torn apart at the moment for cleaning and Mr. Barr has an o-ring kit on the way. Valve adjustment is on the to-do list as well but it would be nice to get the carbs closer before putting it all together again.

Jets are stock 95/15 and the one needle I've taken out is in the 3rd slot from the top. Air screws were all about 1 1/4 turn out except for #1 which was an extra 1/4 turn and the only one that lined up with the notch. I got in too big of a hurry and didn't check the pilot screws, but they were all in noticeably different positions and the #1 pilot screw had a different head on it.

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The bike still has the stock air box with what looks like a new filter, and an open header. I'm at 1300ft here in Kansas and was wondering if I should step up to 100 for the mains? Should I leave the needle as it is? And I think I read somewhere that the pilot screws are set 1 turn out for exhaust. Is this true?

[tkent02]

No if anything you need smaller mains for higher elevation but at only 1300' that's not required. Check the can timing. It's off a tooth our two on a lot of old bikes, can cause a very gutless engine. Could be a clogged exhaust too. Probably a bunch of little things wrong so check everything.

[tkent02]

Just saw the open header comment. Yeah it needs bigger jets for that.

[Throttlejock]

I just got a little worried seeing guys with much bigger mains with not a lot of mods. I'm still pretty green to all this but I have the manual pulled up on my phone so hopefully I'll get it figured out. Exhaust doesn't seem clogged but couldn't hurt to pull it off and be sure.

[Throttlejock]

Just saw the open header comment. Yeah it needs bigger jets for that.

Just one step or bigger?

[rudeman]

What header are you running?

[Throttlejock]

What header are you running?

I have no idea. Could be aftermarket or may even be stock, but it's hacked off just before the brake pedal.

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[rudeman]

I highly recommend that you get a legit header (which those are not) or a set of stock pipes. Stock pipes are tough to come by but a Vance and Hines header will only set you back about $365. Those open pipes don't scavenge properly if at all and it probably doesn't endear you to your neighbors (and law enforcement).

[Nessism]

Good god man, get a muffler on that thing or you are just wasting your time trying to tune it.

[Throttlejock]

What's the opinion on MAC 4-1? Always had a thing for black exhaust but can't find a Vance and Hines set that isn't chrome or polished.

[Frank Z.]

This San Diego CL seller may work with you on shipping to KS. http://sandiego.craigslist.org/csd/mpo/5463917044.html


SUZUKI GS1000 EXHAUST - $200 (EAST COUNTY)




This exhaust came off a 1979 Suzuki GS1000. May fit other years. Good shape. Please call 619.249.612O. Thanks.

[Throttlejock]

Awesome. Thank you. I wonder how much shipping would be though. The MAC I found was about $300 brand new with free shipping

[Throttlejock]

Seller isn't sure what exhaust it is. If I go this route, should I up the main jets to 100? Based on the chart I found, it says to go up 2 sizes for 4-1, up one for drilling air box, minus 1 size after total. 100 still seems small compared to other guys, and V&H say to go up to 117.5 or somewhere around there for their exhaust. There seems to be a lot of information out there, but it's conflicting.

[chuck hahn]

Heres your reference chart

http://www.jockeyjournal.com/forum/showthread.php?t=64769

EDIT....Using the chart, you can drill them bigger. Harbor freight has cheap micro drills and number drill sets.

[Throttlejock]

Alright, brass tacks. At 1300' elevation, with stock airbox and Mac 4-1 with or without a competition baffle, what should I do? Currently stock main and pilot jets and the needle clip is 2nd from bottom. I would prefer to buy proper sized jets than drill the stock, in case I forget and/or sell the bike.