78 GS1000 ready to re-jet.... a few questions (Keith?)

[renobruce]

OK.. just about ready to install the K&N pods, V&H 4-1, and re-jet. I have the pods, the pipe is on the way, but I need to buy jets.

What size(s) should I buy?

The carbs have the stock 95's in them, and I have 4 of the 102's that came with my rebuild kits for a 750.

I live at 5,000 ft. elevation. Most of my riding will be between 4,000 - 7,500 ft.

Also, (dumb question) with my new pipe, do I use the stock pipe flanges/collars?

[Hoomgar]

Bruce, I can help a bit here. For the pipe I am not sure. I had my V&H installed for me and it was a Kerker that came off so I am not sure.

But for the jetting on this bike. I encourage you to get a DynaJet Stage III jet kit for it. Save yourself a lot a grief and just get it. It will give you the needles and jets you need for that exact setup.

Before you start make sure...

Valves are adjusted correctly.

Intake boots are good with no leaks and sealed on with good o-rings. Use some hi temp grease to get a good seal.

Make sure the timing is spot on if still using points.

Check to make sure all four cylinders have good and even spark. Use a new set of plugs.

Now... This is if you are using the stock vm26ss carbs:

DynaJet stage III jet kit

e-clip on the forth position from the top of the needle and no spacer.

Use the 138 main jet provided with the kit.

Make sure your pilot circuit is stock! pilot jet should be the stock #15 jet.

Set your pilot fuel screws at 2 turns out and the air screws at 1.5 turns out to start.

Give it a good bench sync first then once installed warm it up good and adjust for max idle with the air screws. Should be somewhere between 1 3/4 to 2 1/2 turns out on each.

Perform a good vacuum sync at 3000 to 3500 RPM. Level all 4 the same. Bring the ones with higher readings down to match the lowest one.


This will get you really close if not help you nail it right off.

[renobruce]

Thanks, Hoomgar.

The valves are adjusted, new Dyna S and Dyna Coils, new wires and plugs. New intake boots and o rings. Timing is correct.

The big question was/is the size of main jets. As stated, I live at a high altitude. My 1150 has always run a little rich up here, but I never have messed with it.

I put an Edelbrock on my pickup, which came with the stock jets for sea level. The high altitude and low humidity made it run way, way too rich... had to go way down on size to get it to run good and pass smog. I'm just wondering if I will have the same problem with the Stage III kit.

[Hoomgar]

I can almost guarantee you will. But now I defer to someone with more experience.

A suggestion would be to lower the needle 1/2 space with a spacer and try the pilots at 1.5 turns out instead of 2 for starters. I know my bike runs noticeably richer at higher elevations.

[KEITH KRAUSE]

Bruce, I can help a bit here. For the pipe I am not sure. I had my V&H installed for me and it was a Kerker that came off so I am not sure.

But for the jetting on this bike. I encourage you to get a DynaJet Stage III jet kit for it. Save yourself a lot a grief and just get it. It will give you the needles and jets you need for that exact setup.

Before you start make sure...

Valves are adjusted correctly.

Intake boots are good with no leaks and sealed on with good o-rings. Use some hi temp grease to get a good seal.

Make sure the timing is spot on if still using points.

Check to make sure all four cylinders have good and even spark. Use a new set of plugs.

Now... This is if you are using the stock vm26ss carbs:

DynaJet stage III jet kit

e-clip on the forth position from the top of the needle and no spacer.

Use the 138 main jet provided with the kit.

Make sure your pilot circuit is stock! pilot jet should be the stock #15 jet.

Set your pilot fuel screws at 2 turns out and the air screws at 1.5 turns out to start.

Give it a good bench sync first then once installed warm it up good and adjust for max idle with the air screws. Should be somewhere between 1 3/4 to 2 1/2 turns out on each.

Perform a good vacuum sync at 3000 to 3500 RPM. Level all 4 the same. Bring the ones with higher readings down to match the lowest one.


This will get you really close if not help you nail it right off.

Mark, what am I gonna do with you? You forgot to tell him to remove the floatbowl vent lines too.
renobruce, I always suggest the DJ kit too. If you read Marks topic about re-jetting his bike, you'll see we got it going after installing the kit. Before the kit, nothing but poor results. If you like, read that topic, but get comfortable!
If you're bent on trying to use larger mains and the stock needle jet, here's a ballpark guess. A DJ 138 main is about the same size as a Mikuni 130 main. The DJ 138 works well in my bike, but I'm at lower elevation. With your elevation in mind, I'd try either 125 or 127.5 Mikuni mains and test. It's generally better to start on the richer side when jetting. So I'd probably try the 127.5 first. Hope it works if you try it. Some shops will take back/swap the jets if you don't mark them up with your tool??
I believe your stock jet needle will only work in either the bottom position, or the bottom position with a .023" thick spacer on top the e-clip.
Normally, a 17.5 pilot jet is needed with the stock needle and your mods. But your elevation may allow the 15 pilot jet to work with some pilot fuel screw changes.
The jet kit would allow better results if you ride at lower elevations too. With the stock needle/pilot jets, you'll run lean and spit out the carbs if you ever ride at much lower elevations.

[Hoomgar]

Mark, what am I gonna do with you? You forgot to tell him to remove the floatbowl vent lines too.

8O

Well,



um,


wait...




I know I know, I wanted to leave something for you to tell him :roll:

Yup, that's it

Also remember to plug your vacuum line in the carbs that goes to the petcock when your syncing the carbs with the tank off. Ain't Keith? <poke> <poke> :twisted:

[renobruce]

Thanks, Keith. I will get what I need and go from there. BTW, on your V&H pipe, do you use the stock flange/coller/gizmotchies or do they get left off? I couldn't tell by the pics on your website.

[KEITH KRAUSE]

Thanks, Keith. I will get what I need and go from there. BTW, on your V&H pipe, do you use the stock flange/coller/gizmotchies or do they get left off? I couldn't tell by the pics on your website.

V&H uses it's own flanges. But they've changed their flange set up since I bought my pipe. My flanges are welded/fixed. I believe yours will be where they slip up to the head? Just make sure any changes allow you to use the same length bolts. You may/may not need longer bolts?? Obviously, if they're getting tight and you only have a few threads biting, you would need 5mm longer bolts. Some suggest using a little anti-sieze on the bolts. Many more suggest new bolts should be used at this time. I believe correct torque is about 9-10 ft/lb? Tighten them gradually/uniformly.
And buy new gaskets.

[renobruce]

OK, Guys, I'm baaaaaack.

I bought the Dynojet kit. Base settings: DJ138, needle grove #2 with adj. washer above. Fuel screws 2 1/2 out. These settings are probably for sea level. Any suggestions on a base setting for me at 5,000 ft.?

Much appreciated!!

[KEITH KRAUSE]

OK, Guys, I'm baaaaaack.

I bought the Dynojet kit. Base settings: DJ138, needle grove #2 with adj. washer above. Fuel screws 2 1/2 out. These settings are probably for sea level. Any suggestions on a base setting for me at 5,000 ft.?

Much appreciated!!

OK. Quick reply since I'm off to work.
Base settings are too lean in my opinion/experiences.
I'm trying to keep your "richer" elevation in mind so its not an easy guess with only two minutes to think. I can't say how much your elevation will effect the needle circuit and I'd like to hear back what the results are at 1/3 throttle test.
The 138 mains, absolutely!
Jet needle e-clip should work in the 4th position from the top, best to err on the side of rich and test. If too rich, try placing the jetting spacer directly on top the e-clip in the same position. This would be the same as position "3 1/2". Be SURE you re-install the two jet needle plastic spacers in the correct order. Thicker one goes above the e-clip and any spacer used, thinner below the e-clip.
REMOVE the two floatbowl vent lines and leave the ports open.
Turn the pilot fuel screws (underneath) an additional 1/2 turn out from where they were (if it was running right). If you're not sure, try 1 1/2 turns out for starters. Set the side air screws at 1 3/4 turns for starters, then start/warm up the bike and set for highest rpm. Fine tuning of the pilot fuel screws will almost always be necessary.
You MUST vacuum synch the carbs as part of re-jetting. Accurate plug reads/performance depends on it.
Talk to you later if you need help.

[renobruce]

OK, Guys, I'm baaaaaack.

I bought the Dynojet kit. Base settings: DJ138, needle grove #2 with adj. washer above. Fuel screws 2 1/2 out. These settings are probably for sea level. Any suggestions on a base setting for me at 5,000 ft.?

Much appreciated!!

OK. Quick reply since I'm off to work.
Base settings are too lean in my opinion/experiences.
I'm trying to keep your "richer" elevation in mind so its not an easy guess with only two minutes to think. I can't say how much your elevation will effect the needle circuit and I'd like to hear back what the results are at 1/3 throttle test.
The 138 mains, absolutely!
Jet needle e-clip should work in the 4th position from the top, best to err on the side of rich and test. If too rich, try placing the jetting spacer directly on top the e-clip in the same position. This would be the same as position "3 1/2". Be SURE you re-install the two jet needle plastic spacers in the correct order. Thicker one goes above the e-clip and any spacer used, thinner below the e-clip.
REMOVE the two floatbowl vent lines and leave the ports open.
Turn the pilot fuel screws (underneath) an additional 1/2 turn out from where they were (if it was running right). If you're not sure, try 1 1/2 turns out for starters. Set the side air screws at 1 3/4 turns for starters, then start/warm up the bike and set for highest rpm. Fine tuning of the pilot fuel screws will almost always be necessary.
You MUST vacuum synch the carbs as part of re-jetting. Accurate plug reads/performance depends on it.
Talk to you later if you need help.

Just double checking.... when you say "fourth position from the top" do I count down from the top to the 4th notch, or count up from the bottom?
I took it to mean count down from the top which puts me 2 up from the bottom.

[Hoomgar]

Just double checking.... when you say "fourth position from the top" do I count down from the top to the 4th notch, or count up from the bottom?
I took it to mean count down from the top which puts me 2 up from the bottom.

Having taken the same exact advice on the same parts for the same carbs from the same guy I can assure you, you have it right

[KEITH KRAUSE]

Thanks Mark. Probably late but yes, the 4th groove down.