Carb settings Actual good carb settings!

[adcofcolumbus]

Okay guys so just as the title says carbs jetting information is all over the place even when I look in the main technical notes I'm in Columbus Ohio and elevation of about 900 ft and I have a 1982 Seca 400r.
It's kind of odd that the stock jets are two different sizes (the mains) mine being 117 and 127 and I'm switching the gas tank to a non vacuum style petcock , not sure if this is the reasoning for having a higher jet on that side but I did read that they could be the same. The bike will have two pod filters ( yes I know they are a hassle) and straight through slip-on pipes just looking to see if anybody knows what the best jetting and carb settings would be for me roughly

 

[adcofcolumbus]

Uhh..... 7 months later? Anybody alive in zombieland?

 

[CaptChrome]

Reality check - you are really going to have to sort this out yourself. You may end up with +1 or +2 on pilot jets, maybe +1 on the main and also need to shim your needle some. But who knows - only your bike with tell you the answers.

The truth is that no one on here will have the exact same setup as you. Are you using the ugly looking, but high quality pods or the good looking crap pods? Are you using no intake, a home made intake or OEM intake? What are your float bowl fuel levels? What is your compression? What is your timing? And on and on.

You need to go back to basics and start with idle carb tuning beginning with a stock jet setup. The position of the idle mix screws will tell you what you need to do with the pilot jets (if they are 4+ turns out, you should jet up on the pilot, if they are less than 2 turns out, your pilots might be too large). After that, you will need to ride the bike and sort out the mid-range and WOT performance to determine what needs to be done with the needle position and main jet. There is no formula here.

Uhh..... 7 months later? Anybody alive in zombieland?

I wouldn't hold your breath waiting for someone to give you the answer.

 

[adcofcolumbus]

This is evident as I would be dead along time ago. Shame there's just no interest or knowledge like there once probably was on this platform..... Just a shame!

 

[GuyS]

Just ran across this thread. I have a 82 Maxim 400. I agree the DOHC engines like the Seca and Maxim use, is very difficult to source information. Yesterday for the first time since rebuilding the carbs (ultrasonic cleaned etc.) I took the bike for a short road test. I found information that the 82’s used 115 and 125 jetting (125 on the right carb). I replaced the float needle and float seats with new from XSmike. I replaced both pilot jet (42.5). I set the float bowl height at 24mm (this too was recommended from research buried on the internet). I used the tube method to verify the float level at 3mm from the float bowl/carb joint. I benched sycn’d the carbs (I haven’t tested the manometer method yet). I bought a brand new OEM air filter. I set the pilot idle jet screws at 2 1/2 turns. So basically I returned everything back to factory specs. The bike started up right away. It idled at 500 rpm so I increased it to 1200. I drove it down the block and it had very smooth acceleration and pulled really strong! I got it up to 6000 rpm no problem. My bike riding skills have atrophied from 20 years of not riding so it didn’t try it at highway speeds. I am planning to today or tomorrow. If I could post the video of it’s running I would but I’m not sure how to do that. Anything I’ve tried so far greys out the video.

 

[adcofcolumbus]

Just ran across this thread. I have a 82 Maxim 400. I agree the DOHC engines like the Seca and Maxim use, is very difficult to source information. Yesterday for the first time since rebuilding the carbs (ultrasonic cleaned etc.) I took the bike for a short road test. I found information that the 82’s used 115 and 125 jetting (125 on the right carb). I replaced the float needle and float seats with new from XSmike. I replaced both pilot jet (42.5). I set the float bowl height at 24mm (this too was recommended from research buried on the internet). I used the tube method to verify the float level at 3mm from the float bowl/carb joint. I benched sycn’d the carbs (I haven’t tested the manometer method yet). I bought a brand new OEM air filter. I set the pilot idle jet screws at 2 1/2 turns. So basically I returned everything back to factory specs. The bike started up right away. It idled at 500 rpm so I increased it to 1200. I drove it down the block and it had very smooth acceleration and pulled really strong! I got it up to 6000 rpm no problem. My bike riding skills have atrophied from 20 years of not riding so it didn’t try it at highway speeds. I am planning to today or tomorrow. If I could post the video of it’s running I would but I’m not sure how to do that. Anything I’ve tried so far greys out the video.

Nice sounds like you got it figured out are using pod filters or the original air box?

 

[GuyS]

CaptChrome gives good advice, which I’ve used throughout my restoration. Go “back to the basics” and make sure she’s running right. Then make your modifications as you go to find out what works and doesn’t work so well. I am totally back to stock including the stock airbox. I sourced parts all over the place so let me know if you need help on anything.

 

[GuyS]

Took the bike out for a ride and 6000 rpm, strong pull all the way up from idle. There’s some backfiring around 3000 rpm when I release the throttle. More so when it warms up. Not sure what is causing that but assume the idle circuit is too rich? My setting of 2 1/2 turns may be slightly too much. That said I haven’t manometer the carbs yet, and will try the first.