Re-Jetting GS750L

[Guest]

Currently trying to figure out how to rejet my '79 750. After searching for days, Im still really confused.



I am going to be running stock pipes with pods. (Bike didnt come with the stock box, otherwise I would just run it stock)

My research shows that I can use APE filters in the 42mm variety, PN 005-122 which will work on the VM 44mm body.

1. My findings seem to show that I should run a 120 or 115 main, since stock I have a 100 main. But I could only find this for people running pipes and stock box, is the same true for pods+stock pipes?

2. Looks like a 20 pilot and needle raised one notch will work fine as well. When raising the needle, does that mean moving it towards the "needle tip" so there are more notches on the top than the bottom?

3. All the carb rejetting recomendations I have found relate to the CV carbs and not the VM carbs. Are they the same?




4. After taking my carbs apart, I found that my pilot air screws were set at 3/4, 3/4, 3/4 and 1-3/4 turns to bottom. Shouldnt they all be at 1-3/4 turns, roughly?

5. My pilot fuel screws were set at 2-1/2, 2-1/2, 2-1/2 and 2. What the heck do those need to be?

6. My jet needle clips are not in the middle like they should be for stock carbs. They are in the second from top (away from the sharp tip). The needle is also stamped 5DL36. Is that a stock needle?




Sorry, I know its another newb with carb questions.

[Big T]

1. 115 main - that's up six sizes, they go by 2.5 increments - I'd say you'll end up in the 110-115 range

2. You are correct. Lowering the clip raises the needle, allowing more fuel to come out

3. Pretty close - the CV just don't have all the adjustments available the VMs have

4. 1 3/4 is where you start

5. Fuel screws should be about 1 turn out

6. Sounds like someone went the wrong way on the needles. I can't remember the stock needle, check the OEM carb specs at the top of the page

https://www.jetsrus.com

[Starboard M]

I called Z1 yesterday and the guy I talked with suggested I try the stock jetting again and read my plugs before I rejet them.


He did say that 110 would be a little to rich for only running pods, and suggested a 102 or 105. So who knows.

[Starboard M]

Did some searching on google, and didnt find much. Then I realized I should try a search on the GS Resource.


Turns out the 5DL36 needles were actually stock on a '79 750N with the VM carbs due to EPA regulations.

Just found this which I am posting in carb spec thread from this website:

http://motorbikearchives.com/Bike-Tests/Road-and-Street/Suzuki-GS750EN-1979.html

The GS750B came with a # 100 main jet, 0-6 needle, 5F21-3 jet needle, and # 15 pilot jet. The GS750C (1978) and GS750N (1979) carburetors were changed to a #102.5 main jet, 0-4 needle, 5DL36-2 jet needle and #15 pilot jet.

What that all means is that the GS750N is leaner at the small throttle openings usually encountered in EPA emissions test modes. The dual-taper 5DL36-2 jet needle is initially leaner, secondarily richer to smooth the transition from idle to off idle, (or from small, steady-state carb openings at low speeds to gentle acceleration, as encountered in traffic). The float level was also lowered between the GS750B and GS750N, from 26mm to 24mm.


I'll go to these settings and work back from there.

Sounds like I will keep the carbs the way they are for now, and see what it does.

http://www.thegsresources.com/_forum/showthread.php?t=147879&highlight=5DL36