Re-jetting '83 650 Katana

[swaite]

Hello all, I am in need of assistance. I am brand new to the carbureted world, and find myself wishing I had stuck to fuel injection. Too late now, I guess.

Anyhow, I bought myself a 1983 GS650M Katana recently with a few running issues. High idling with a few pops coming out of the exhaust, but otherwise it looked and sounded pretty good. The previous owner slapped some pod filters on and called it a day I guess. There are no capped vacuum lines, so I assume that might be where the high idle comes from.

I have read that when putting pod filters on the carbs, they need to be re-jetted, problem is I have no idea what I need to increase. Below is essentially the only information I've been able to find on my particular bike, and it all looks like Chinese to me. Help?

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 34390
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-0.5 (0.20 +/-0.04)
main jet #110
main air jet 2.0
jet needle 5C45
needle jet Y-7
pilot jet #92.5
throttle valve #135
by pass 0.8, 0.7, 0.8
pilot outlet 0.7
valve seat 2.0
starter jet #45
pilot screw pre-set (1.5 turns back (mixture screw))
pilot air jet #160
throttle cable play 0.5-1.0 (0.02-0.04)
choke cable play 0.5-1.0 (0.02-0.04)

[Nessism]

This kit will make your life easier...http://www.z1enterprises.com/Dynojet...8182-4059.aspx

K&N and APE Pods are the good stuff. All bets are off if you bought some cheap Emgo pod junk.

[swaite]

This kit will make your life easier...http://www.z1enterprises.com/Dynojet...8182-4059.aspx

K&N and APE Pods are the good stuff. All bets are off if you bought some cheap Emgo pod junk.

Nice find on the jet kit! Though, I'm not sure if it applies to my particular bike, it being an '83 and all...

[Nessism]

Nice find on the jet kit! Though, I'm not sure if it applies to my particular bike, it being an '83 and all...

It's the same as for your bike. Dynojet does a crappy job of listing all models that their jet kits fit.

[swaite]

Ordered the kit! Does anybody have experience with the Dynojet kits? I'm hoping it comes with at least some vague instructions because I can't figure out what the drill bits or lone screw are for.

Relating to the pod filters, should all of the vacuum lines that are no longer being used be capped off? I think there are only two. Like I said, the PO must've just slapped the pods on, stood back and patted himself on the back because that's all that was done.

[TheCafeKid]

Ordered the kit! Does anybody have experience with the Dynojet kits? I'm hoping it comes with at least some vague instructions because I can't figure out what the drill bits or lone screw are for.

Relating to the pod filters, should all of the vacuum lines that are no longer being used be capped off? I think there are only two. Like I said, the PO must've just slapped the pods on, stood back and patted himself on the back because that's all that was done.

There is only one vacuum line, on the number two carb (numbered left to right sitting on the bike) and that should be hooked up to your fuel tap as stock taps are vacuum operated.
The other nipples are vent lines, and when running a jet kit, they should be left as they are (no hoses)

The Dynojet kit comes with decent instructions, follow them and the only change you will likely have to make is the needle clip setting. You will need to know which jets are which and what the different parts within the carbs do and are..so study up on here and Nessisms carb rebuild tutorial as it will familiarize you with the names of everything. (the kit instructions don't have pictures )

If the pods installed are EMGO, or just cheap cone shaped filters they're junk and will cause you more problems than help. Invest in better.

[swaite]

I don't know what brand of filers they are, but they look pretty cheap. I suppose replacements are in order. I was thinking some UNI foam filters.

Upon further research and inspection, I think I might be returning the Dynojet kit. Jumping from 110 to 155 seems ridiculous, even with pods and a 4-1 exhaust (which I don't have).

[Nessism]

The Dynojet jet numbers follow a different scale than Mikuni.

[BassCliff]

Greetings and Salutations!!

Hi Mr. swaite,

The Mikuni jets are measured in flow rate. For example, a 115 main would deliver 115cc of fuel per minute. The Dynojet jets are measured in diameter, a 155 is 1.55mm in diameter.

For a little bit more background reference, let me dump a TON of information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Cleanup Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. This is what NOT to do: Top 10 Newbie Mistakes. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Suzuki_Don]

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 34390
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-0.5 (0.20 +/-0.04)
main jet #110
main air jet 2.0
jet needle 5C45
needle jet Y-7
pilot jet #92.5
throttle valve #135
by pass 0.8, 0.7, 0.8
pilot outlet 0.7
valve seat 2.0
starter jet #45
pilot screw pre-set (1.5 turns back (mixture screw))
pilot air jet #160
throttle cable play 0.5-1.0 (0.02-0.04)
choke cable play 0.5-1.0 (0.02-0.04)

Just noticed some incorrect details on your list of specifications.

The pilot jet is #42.5 and not #92.5 as listed in your information.

[swaite]

I just copied and pasted it from the sticky at the top of this forum, so I can't really confirm/deny its validity. In addition, the chart referenced here states for a 1983 GS650MD (Katana, I think. I'm still not 100% on the exact model I have) the pilot jet is 92.5 pounds. I still haven't got my pilots out to confirm because I don't have a screwdriver that will fit.

I've also been doing some more research on the Mikuni vs. Dynojet jets and found that the difference is DJ x .9375 = Mikuni numbers. So that leaves me with 145# Mikuni equivalent. Still more than I have seen other people stepping up to with just pod filters.

The Dynojet kit was also shipped to me without any instructions what-so-ever. The picture on the box also shows a certificate for one free dyno run. Also, not included. What gives?

[Suzuki_Don]

I still think the #92.5 pilot jet is way too big. The next largest pilot jet I could find for a GS with CV carbs was a #47.5 and that was on an 1100. So the #92.5 is twice the size of that. I think you will find when you get your pilots out they will be #42.5. I just didn't want you to pull the pilots on your carbs see they were #42.5s and think they were wrong and start looking for a set of #92.5s whick might not exist.

[TheCafeKid]

Who is selling these kits with no instructions?? That's like the third person who's gotten one with no instructions. That seems somewhat shady.

[swaite]

Who is selling these kits with no instructions?? That's like the third person who's gotten one with no instructions. That seems somewhat shady.

I got it from z1enterprises.com who I thought was a reputable store around here.

[koolaid_kid]

Just go here and download instructions for a different GS. They will be very similar: http://www.dynojet.com/jetkits/motorcycle/suzuki.aspx