1980 GS450 Carb sync

[apopleptic]

last time I took them aparts was last saeson. the o-rings weren't broken or anything so I just examined and reassembled. It wasn't what I would call a proper rebuild, more a checkup. the rebuild happens now that I find there is a hidden part (air adjustment screw) that has never seen the light of day.

[pete]

All good, my apologies... too many carb threads!

I was actually thinking of JShapiro's issue when I said that...

[apopleptic]

Ok, small update here as I continue waiting for some parts for the carbs, specifically o-rings which are on the way at this point from http://ww.cycleorings.com and I opted to get the replacement bolts since the screws on my boots were rusty.

Hopefully I'll get these soon since I just had a car accident and need to work on regaining the use of my thumb so I can ride the bike while I am without a car.

I read through both of the carb rebuild tutorials from Mr Nessism and My Flaming Chainsaws and followed the latter which is specifically for the 450 and more closely matched my exact carb. Two things, how mandatory is the carb dip? and when I ordered replacement screws to reassemble the carb I was checking for fitment and the specs mentioned in mr FC's rebuild seem correct M6x1.00 M5x.0.80 and M4x.070 but when I go to put the new bolts into the carb bodies they start a little bit in and then become tight and I don't want to force them without checking. they are not cross threading.

I am attaching a pic of the two screws next to measuring calipers, they look the same to me. the photos are clipped to scale so both can be in one picture. I had a similar issue when I went to replace the nuts on the oil filter cover where the old bolt fits right on an m6 post, but the new m6 wouldn't go on the post more than three rotations. Is this just what happens when mixing old and new? or are these actually the wrong threads.
any feedback?
Thanks

[cowboyup3371]

I'm not sure I understand your question correctly? How else do you plan to dip and clean them if you don't buy the Berryman's? You cannot take shortcuts here or you will be doing it all over again later.

[apopleptic]

I'm not sure I understand your question correctly? How else do you plan to dip and clean them if you don't buy the Berryman's? You cannot take shortcuts here or you will be doing it all over again later.

OK, this may be TMI and I don't want to sound insolent, or unappreciative of anyone's helpful suggestions. If you don't want to know a little backstory, only read the next sentence and then ignore my posts going forward. I know you're right about redoing it later as a result.

Honestly, I'm more concerned with the screwsdamaging my carb so I can't use it as emergency transport (which is what I need right now). not that worried about doing it over again in a month or two. more interested in being able to get a few miles for food or job interviews. the bike was running fairly well before this rebuild was started. the insides of these carbs are as clean as all the after pictures I keep seeing in tutorials. the outside has minimal grime. the floats look like they could be 6 months old instead of 30 years. the jets were completely clean. even the orings looked ok (replacements on the way and why I'm waiting to put it back together at all). If I need to do the carb dip ( do I really?) it will be at a later time so I don't have to walk a few miles to the store and then back with a gallon of cleaner that I can't afford that well because I'm unemployed right now and facing over $14k in medical bills from chopping 1/3 of my thumb off a few weeks ago.. and if I don't need to spend the extra cash this second, I'd rather put it towards the deductible for getting my car fixed.

PS, it is really extra difficult rebuilding this thing having just gotten the bandages of this week and still have some stitches on the nub of my thumb which is quite sore still (especially when I bumped the airbox taking the carb out)

[pete]

Ouch! That had to hurt! It was bad enough when I slammed the skin of my thumb with a makeshift slide hammer and nearly severed a chunk there...

Anyway, the screws in FC's carb rebuild are definitely right, standard M4, M5, and M6 threads on them.

I did the M4's and M5's on mine but didn't bother with the M6's and I had no troubles at all just asking for M4 and M5.

That carb does look nice and clean too actually, but if you have some carb cleaner around you may want to spray some through the passages just to be sure.

[cowboyup3371]

The choice is yours after all so if you think they are okay than don't worry about it. Just know there are passages in there you cannot see and if those are clogged you'll have issues. At the very least, I would spray into each hole and make sure stuff comes out the other ends.

Sorry to hear about your thumb. Hope everything works out for you.

[apopleptic]

I have confirmed that all the passages are clear of obstruction, and I have began the reassemble by putting the chokes back together and mounting both carbs back on the bracket and doing a bench sync to make sure the throttle valves are spaced as close as I can get them. The screws that seemed questionable have gone in with some resistance, but I guess probably ok. none stripped and anti sieze was used. The o-ring's didn't come in the mail today so I guess I am going to be sitting home all weekend. Hopefully Monday those o-rings get here by mail so I can finish and put the arb back on. Then when I get the call I can go get the rest of my parts from across town.

[pete]

Waiting for parts can be so frustrating, but at least usually the wait is worth it

[apopleptic]

so very true. I have a feeling that is I had known about those rubber sleeves that went between the airbox and the carb I may never have had a problem with this bike. unfortunately they aren't actually shown in that blowout diagram of the airbox. well, they do have a number pointing at them, but usually something like that would be shown outside of the airbox in a diagram like that. I hate having to look at the bike as emergency transportation, but I wish it would fill that role for me right now.

[pete]

I hear ya and I found exactly the same thing with the fiche not being clear.

Given the years between pulling the carbs off and then doing the cleaning, I had these strange rubber things attached to the carbs that I didn't know what to do with.

Ended up posting a question on here about what they were because it wasn't clear in the diagram, so it is definitely a bit confusing, and yes I suspect you're right as they have a big impact on your intake working right from the air box.

It's definitely a bummer not having transport too, so hopefully once you get those O rings you'll be all set.