Tuning plan

[Steverk]

After some great help from those of you on this forum, I was able to take the bike out on a maiden voyage last weekend. I thought I would post a pic also. Now you purists on here should know that this bike was a near basket case to start and would have unlikely ever have seen the road again.
now that she’s running it’s time to tune. Now reading a lot of other posts on this forum I have learned that there are different versions of these carbs as well as jetting. Since I have painted the carbs black, I don’t know which particular version I have, but they are not the version with the connected main and pilot circuit. I have been meticulous in cleaning every port, nook, and cranny. Removed all the removable bits, jets, idle screw, etc. someone at some point have been inside these carbs before. The pilot jets are marked 42.5, main jets are stamped with a “120” and no markings on the needles, leading me to be mistrustfull of these pieces. Also of curiosity is the pilot air jets are marked “190”. So as I begin this journey of the tuning phase beginning with carb syncing and idle mixture adjustments, do I bite the bullet and replace all suspect components (needles are hard to find) or address tuning issues as I work thru idle to WOT?

[DiverRay]

If you are not sure of what you have, the easy way is to start with tuning and see how it goes. If you have issues, then look at replacing suspect parts, ONE AT A TIME. Although some parts are not Mikuni, they may have been working with the carb set-up. The good thing is you KNOW what parts are not Mikuni, and so you have a start point if the carbs do not want to tune.

[Larrym]

Given my recent experience(s) with "Running/Tuning/Syncing/Idle Mixture" on my own bike? (O_o)

I'd start here-



I'd also shy away from non-Mikune jets and parts from the cheepee Taiwan aftermarket kits. ( •_•)

It's the difference between the bike being "running/drive-able" and being a Super Bike. (づ ՞ਊ ՞ )づ

[jkorn]

Larry. You setup looks amazing. Easy to get them all the same…. But how do verify they are at the correct heights?

[Steverk]

Larry. You setup looks amazing. Easy to get them all the same…. But how do verify they are at the correct heights?

Looks like that's the purpose of the straight edge and calipers. Larry are the float bowls drains just for the purpose of verifying fuel levels in the float bowls, or do you keep those lines on all the time? Clever rig that I will adopt.

Thanks for the advice fellas. Let the games begin!

[cajun31]

I am sure Larry will chime in, but for clarification, in the first picture that he posted, when the fuel is applied to the the carbs the fuel levels will show in the tubes. The proper level should be at the bottom of the float bowl screws across all four carbs. If the level is incorrect you will need to adjust the float levels one by one by bending the float tangs until all four are set correctly and at the same heights. Once you have them set up correctly you remove those tubes and close off the float bowl drain plugs. On the carbs with drain plug screws you just put them back in the bowls and on the newer carbs you just turn the drain plug screws in until they are closed. The 81 and later carbs all had the latter screws and the earlier carbs actually have drain screw plugs and washers. In order to incorporate this process you have to have a set of four special drain plug replacements that allow you to hook the clear tubes up to them. Some have had success with buying the right size diameter hose so they can basically just shove or screw the hoses into the bottom of the bowls. Hopefully these last two lines are wrote don't confuse rather then help, but hopefully you can envision what I am describing.

Look at this whold thread, but particularly post 37 by Larry. Those are the fittings I was trying to describe. Idle mixture/etc one rich plug - XS11.club Forums

[Steverk]

So will the 190 pilot air jet give me a hassle with a too lean a condition low in the rpm's, or can I compensate with the mixture screw?

[Larrym]

Larry. You setup looks amazing. Easy to get them all the same…. But how do verify they are at the correct heights?

I went with wut Cajun31 said-

The proper level should be at the bottom of the float bowl screws across all four carbs.

Here's wut they were even after setting the float height/distance per the repair manual. (_Oo)








After I adjusted/checked/adjusted? ¯\_(°,_｣°)_/¯

They were all at/or near the squiggly red line shown here-





The pic shows the screw, the washer, and the bailing wire wrapped round the screw. Red line represents where the screw/washer would be when bailing wire is removed as I do NOT ride around wit these set up. ʅ(°_◞°)ʃ

Note- fuel level in #3 was not only up/over the bowl surface. It wuz pouring out of the main needle jet. Very bad.... ʅ(°_°)ʃ

[Larrym]

Looks like that's the purpose of the straight edge and calipers. Larry are the float bowls drains just for the purpose of verifying fuel levels in the float bowls, or do you keep those lines on all the time? Clever rig that I will adopt.

Thanks for the advice fellas. Let the games begin!

Straight edge/level is to show that the "Carb Pagoda" itself is level from side-to-side fOaR accurate readings. (^_^)

I mean...in theory when I cut the 2X4 I did my best to ensure the legs were the same length so iffin' I put the Pagoda on any level surface it'd wurky. Just that my work bench was a little off and I wanted to double-check. 乁(ツ)∫

The digital calipers come in handy when you wanna change the float level in .5mm (1/2 millimeter) increments until the fuel level gets to the sweet spot. ＼(ﾟｰﾟ＼)

[Larrym]

So will the 190 pilot air jet give me a hassle with a too lean a condition low in the rpm's, or can I compensate with the mixture screw?

Ummm....I dunno. My bike is stock. ╮(╯_╰)╭

But I DO know where's I'd start looking iffin' I wanted to figure out what jets I got and needed fOaR a set up like yurs. (- ‿◦ )

https://xs11.club/forum/maintenance/...ls-and-jetting

https://xs11.club/forum/modification...ecommendations

The MATH in the second link should be of interest to you. (◕‿◕)

[jkorn]

I have gone thru multiple settings annd jets and like where I’m at now. Problem is my documents are back home and not there for a month. I will reply then.

[jkorn]

So, I have the bolts with washers at the bottom of the bowls on my 79F. Where are you finding replacements with the nipple on them to attach the clear hoses??

[Larrym]

So, I have the bolts with washers at the bottom of the bowls on my 79F. Where are you finding replacements with the nipple on them to attach the clear hoses??

I ordered mine from Amazon...here-

https://www.amazon.com/dp/B07468TJVH...roduct_details

BUT iffin' there's a auto parts store you like go there and ask fOaR 8mm grease fittings/zirks. (´◡`)

My area has O-Reilly Auto Parts so...

https://www.oreillyauto.com/detail/c...k+Nipple&pos=0

You DO have to use a jeweler's screwdriver or a pointy set of tweezers to pry out the spring from the threaded side of the fitting. Then the check ball just falls out. (☉_☉)

Save the springs/balls as they're the right size fOaR the detents in the choke rod. (^_^)

Note- there's LOTs of 8mm fittings that'll screw into the bowl bottoms like brake bleeders, etc. But you don't want something so long it'll jam into yur main jet which is right THERE inside the carb, right? The zirks wurky. ( ‾́ ◡ ‾́ )

[jkorn]

Thanks…. Great info…. Jeff

[Larrym]

As you gents are going into an area where NOT knowing wut you need to know befOaRhand can BITE you? (●´⌓`●)

Here's mOaR info that'll help ensure your success in your efforts. (＾-＾)