Sins of the PO and reflections of a newb carb rebuilder of a BS32ss 1980 gs850gl

[Uncamitzi]

I have some questions but I'll ask them at the end .. If you stay with me long enough to get to my questions I admire you.

I'm on my 3nd strip down and cleaning of my carbs. Having only been getting 30 mpg since I got the bike and realizing that the first time I "cleaned" the carbs I may have ignored a lot of advice from this Forum... silly me. This time I have compressed air, a ultrasonic cleaner, some brass wires and brushes for probing and gentle cleaning. I ordered the carb o-ring kit (found on another thread that I will link too if asked)
Way back when I got the bike the PO gave me a box labeled "GS850" Dyna Jet Kit. Inside the kit, he told me were the spare parts and original parts from when he "Dyno Stage 3 ed" the carbs. I had no freaking idea what he was talking about, but I kept the box in my tool kit after a cursory look noting that the instructions were there with a bunch of different jets rods and plugs

The first time I "cleaned" the carbs I took them apart kept the parts separate in containers and soaked each metal part in chem-dip, dried them, and did my best to clean the jets.. but didn't really know what I was looking at then. When it came time to put it all back together I spent most of my time looking at exploded views from the manuals and guessing.. but I got them back together and working at least as well as they worked when I started.. maybe a tad better... but maybe not.

The second time was the first time I replaced o-rings... all that came in the aforementioned o-ring kit... and everything still "looked" clean so I just used a lot of spray carb cleaner and put it back together. Again, things worked..at or about the same as they did before (maybe worse)

I'm now on the 3rd time. I've been at it slowly for about a week now... parts are cleaned, some are shiney. As I've been putting the carbs back together this time I've made some disturbing discoveries.
#1 Main Jets I had switched them back from the #140 size to the stock #115 on the first go around.. I made the newb assumption that the other jets hadn't been played with... (wrong). There were many mismatched jets from carb to carb.... My questions in subsequent posts in this thread will be about that... If I can't figure it out...
carbexploded.jpg
This is the page from the PDF file manual from BikeCliffs website... many of the parts are mislabeled.. Especially the jets .... without further study, a newb (me) would be unclear as to which jet is which... and without reading (in depth) the information starting with this; http://www.iwt.com.au/mikunicarb.htm would not understand the slow cycle from a main jet.
So I'll leave this here.. as my eyes are tired from trying to read the itty bitty lettering on those jets deeper inside the P.O.'s mess.

[Steve]

I applaud you for your persistence.

Hopefully this is not just an exercise in futility.

Have you (or anybody else) done anything to the bike to justify a Dynojet kit?
Stock airbox or pods? Stock exhaust or a pipe?

If you don't get any better results this time around, let me know, I might be able to help you.

.

[Uncamitzi]

Nothing that I can see.. I've cleaned, repaired and repainted (made airtight and sealed) the original airbox. New intake boots and airbox rubber. I use a K&N Filter and clean and oil it regularly. I'm trying to go back to stock settings... I don't see any reason for the Dynojet kit. Everything is stock except that the exhaust pipes are about 3 inches shorter than stock. It looks like he cut and welded them (don't ask me why)

[2BRacing]

…….I'm now on the 3rd time. I've been at it slowly for about a week now...

Have you seen this tutorial?

...

http://zeus.mtsac.edu/~cliff/storage...d_Tutorial.pdf

[londonboards]

Be sure to indentify the jets correctly. If the PO put in the DynoJet jets, they have a different numbering system than Mikuni jets. You really want to go back to stock sizes using Mikuni jets. You can identify these as they are market with a square next to or near the jet size marking.

[KillRamsey]

I'm of absolutely no use to you, but I do wonder where you got your airbox gaskets? Mine are both cracked to hell.

[gustovh]

If the PO did indeed install a stage 3 kit, your carbs have been drilled and require the larger jets, though I think that 140 would be a bit big. You really should read the instructions for the stage 3 kit, it might help your understanding of what the po did.

V

[Uncamitzi]

I'm of absolutely no use to you, but I do wonder where you got your airbox gaskets? Mine are both cracked to hell.

The gaskets that fit under the polished steel covers were in pretty good repair and still flexible. I did use some rubber cement to repair some tears and splits, but that's all I did for them.

[Uncamitzi]

If the PO did indeed install a stage 3 kit, your carbs have been drilled and require the larger jets, though I think that 140 would be a bit big. You really should read the instructions for the stage 3 kit, it might help your understanding of what the po did.

V

Drilled? Where? How? The "instructions" he left in the box don't have anything other than replacement instructions. All the original jets have the mukuni factory marks and fit where the "dynojet" jets were. Actually I don't think this is a proper "Stage 3" kit... it has replacement slides for the diaphragm with the clip installed on the 3rd slot in the fuel needle. (that seems to be the only consistent replacement he made...lol) I replaced them with the original He had different sized fuel jets, pilot jets in each carb. (And I wondered why my mileage has been so bad.......lol) I'm video recording this process.. If I run into any surprises other than the sins of the PO i.e. mistakes I make or questions to post I'll send links to them. Thanks for your reply. Everything is food for thought.

[Uncamitzi]

Have you seen this tutorial?

...

http://zeus.mtsac.edu/~cliff/storage...d_Tutorial.pdf

Yes, Have you seen this one? https://www.youtube.com/watch?v=95nlrP-yn2I&t=1420s

There are a number of good sources..and by this time I think I've watched them all.... I'm still a newb.

[Big T]

The Dynojet kit comes instructions on how to drill a hole in the slides. Look for that instruction and see if it was done
You'll probably want to use the needles with the adjustments to help you tune the carbs

Your story shows why "short cuts are the longest path"

Keep asking questions, post up pictures and you'll have that bike purring in no time

[Uncamitzi]

Ok, IF and I repeat IF the PO drilled the Slide Lift Hole.. #1 How could I tell? #2 How will that effect (affect?) performance if I return the mains and pilot jets to original size. Could I counter with adjusted position of the clips on the Dynojet needles?

[tom203]

Put the stock jetting back in,set mixture screws about 3 turns out and don't worry about whether the slides were drilled- I imagine it would have little effect with stock mains/needles.

[Uncamitzi]

Put the stock jetting back in,set mixture screws about 3 turns out and don't worry about whether the slides were drilled- I imagine it would have little effect with stock mains/needles.

I think I've found all the original jets .. He also had some different sized factory pilot jets... mixed in the 4 carbs... I have seen no post, no theory on the value of having different sized jets in supposedly synchronized carbs.... But then my knowledge of carburetion is, to say the most, limited.

Thanks for the help ... It's cold wet and dreary here for the week, I'm not sure how much work I'm going to get done on the motorcycle...

[Steve]

Yes, Have you seen this one? https://www.youtube.com/watch?v=95nlrP-yn2I&t=1420s

There are a number of good sources..and by this time I think I've watched them all.... I'm still a newb.

I stepped through that video to see if it was any good. By the time I was half-way through, I had made the decision to not continue. If THAT is what you did and are calling the carbs "clean", you need to go back and start over. There is no way that you are going to get the carbs CLEAN without unganging the rack. You need to also get the "choke" plunger out, that requires rack separation. I did not go back to watch the second half of the video to see if any of that was covered, but he was saying "that's all you have to do" to clean the carbs, so I gave up.

Ok, IF and I repeat IF the PO drilled the Slide Lift Hole.. #1 How could I tell? #2 How will that effect (affect?) performance if I return the mains and pilot jets to original size. Could I counter with adjusted position of the clips on the Dynojet needles?

1. The hole on the bottom of the slide will be larger. You don't have any "before and after" reference points, so let's just say that the stock holes are a bit smaller than 1/8" (maybe 3mm?), the drilled holes will be a bit larger.
That hole is also at an angle. Some installers might not know that and have drilled the hole straight in. If that hole does go straight in, you can guarantee it's been drilled, but if it goes at an angle, you don't know if it's stock or the installer knew about it and drilled it properly.

2. The drilled holes will not affect operation much. Go ahead and put the stock needle back in, with all the spacers set properly. The larger hole reportedly allows quicker operation of the slide, but I could never tell. You could also leave the Dynojet needle in place. It might need slot #3 or #4, but riding would have to dictate that.

One other modification that is usually done with a Dynojet kit is a drilled plug that goes into the main air jet. That is the hole that is in the 4 o'clock location in the carb intake. There is a pressed-in jet there from the factory, Dynojet supplies another one that is slightly smaller that gets pressed into place. I have only installed Dyno jets on a couple of bikes, and have never installed those smaller air jets, have had no problems with them. I am not sure if they are all that necessary.

.