Did I break it again? Popping after cleaning.

[TheCafeKid]

Did you check that the vaccum line wasnt pulling gas into it?? if it is it will likely cause a problem.

[Roostabunny]

Did you check that the vaccum line wasnt pulling gas into it?? if it is it will likely cause a problem.

I have never noticed any fuel in the vacuum line when I pull it off or gas in the oil when I change it. Any other ways can I check that?

[TheCafeKid]

pull the carb end off and give it a suck..carefully obviously, unless you have one of those handy MightyVac's...which i dont..lol If you get any gas in your mouth it's likely the carbs will suck gas thru the vaccum line too, which will further your tuning problems.

[Roostabunny]

pull the carb end off and give it a suck..carefully obviously, unless you have one of those handy MightyVac's...which i dont..lol If you get any gas in your mouth it's likely the carbs will suck gas thru the vaccum line too, which will further your tuning problems.

How about connecting a length of 1/4" clear-ish tube to the vacuum port on the petcock? I think I've got some of that lying around at work. This will save me 1.) disconnecting the hose from the carbs and 2.) possibly sucking gasoline, since I'll be able to see the gas in the tube. Or, hopefully I won't see any gas in the tube at all. [-o<

The petcocks been making me nervous for a couple of weeks now anyway - since I read somewhere on GRS that it was dangerous. I keep waiting to come outside in the morning to a puddle of gas and an empty tank. Plus I hear it's potentially hard on the floats, and now this potential "gas in the vaccum line" problem. So I bit the bullet and ordered both the petcock and the airbox boots (2 left and 2 right) from Flatout. Between price and shipping they easily came in under the other two - saved me about 20 bucks on the whole shebang.

I guess the good news is that even though I'm spending more on parts than I planned, I'm replacing stuff that will take another 25 years to wear out again.

[TheCafeKid]

How about connecting a length of 1/4" clear-ish tube to the vacuum port on the petcock? I think I've got some of that lying around at work. This will save me 1.) disconnecting the hose from the carbs and 2.) possibly sucking gasoline, since I'll be able to see the gas in the tube. Or, hopefully I won't see any gas in the tube at all. [-o<

The petcocks been making me nervous for a couple of weeks now anyway - since I read somewhere on GRS that it was dangerous. I keep waiting to come outside in the morning to a puddle of gas and an empty tank. Plus I hear it's potentially hard on the floats, and now this potential "gas in the vaccum line" problem. So I bit the bullet and ordered both the petcock and the airbox boots (2 left and 2 right) from Flatout. Between price and shipping they easily came in under the other two - saved me about 20 bucks on the whole shebang.

I guess the good news is that even though I'm spending more on parts than I planned, I'm replacing stuff that will take another 25 years to wear out again.

Very true! That method would work also..probably simpler too, but i like to do things the punishing way...lmao.

[salty_monk]

I have some 1000G ones that are serviceable. I put new ones on but it turns out 2 of mine were as good as new & 2 have a small bit at the bottom where they have gone hard. They were sealed fine though.

Let me know if the part is the same & we'll work something out.....

Dan

[Roostabunny]

I have some 1000G ones that are serviceable. I put new ones on but it turns out 2 of mine were as good as new & 2 have a small bit at the bottom where they have gone hard. They were sealed fine though.

Let me know if the part is the same & we'll work something out.....

Dan

Hey thanks, Dan - But I'm quick. Once I decided I had them parts ordered within minutes. Four squishy new boots on the way (and a fuel petcock for the stocking)! \\/

I was already planning on doing a valve adjustment next week (got some vacation left) so while I have the tank off I'll replace my petcock and fuel line (the line's old) and then re-attach and re-seal that airbox with the new boots.

Say, I've had my idle slow down the last couple of weeks as well - think that's related? Like the popping, that's a sign of a lean mix too, isn't it? I had to dial up the idle adjustment a smidge to keep it in spec last week and it still sputtered out on me at stoplights twice in the last week.

[bwringer]

Say, I've had my idle slow down the last couple of weeks as well - think that's related? Like the popping, that's a sign of a lean mix too, isn't it? I had to dial up the idle adjustment a smidge to keep it in spec last week and it still sputtered out on me at stoplights twice in the last week.

Absolutely -- these are all signs of lean running.

[Roostabunny]

Absolutely -- these are all signs of lean running.

Awesome - well, I hate breaking stuff, but I sure glad I learned this before I tried to rebuild and re-sync the carbs. It's really opened my mind about how the carbs actually work.

Is this sensitivity to air leaks just a GS issue or is it universal to all four-stroke engines, all non-fuel injected bikes, just these mikuni's, only GS's and mid-'80's forklifts?

[Roostabunny]

Hey, side question - could the film of oil on the front of the airbox come from these mediocre seals from old airbox boots? Seems odd, since it seems like the air would be leaking in, not out. Course, there's a film of oil on the inside surfaces of the box, too.

I'll clean it real good before I install new the boots and seal up the covers with the rubber weatherstripping I bought at Ace yesterday. Just curious what you think about that oil.

[TheCafeKid]

Awesome - well, I hate breaking stuff, but I sure glad I learned this before I tried to rebuild and re-sync the carbs. It's really opened my mind about how the carbs actually work.

Is this sensitivity to air leaks just a GS issue or is it universal to all four-stroke engines, all non-fuel injected bikes, just these mikuni's, only GS's and mid-'80's forklifts?

I have a Yammie XS400 that absolutely will not run off choke with the airbox off. I think it's a CV carb thing mostly, but all bikes will be sensitive to air leaks. The carbs themselves are just picky and have very little tollerance for improper tuning.

[Roostabunny]

Update - although Flatout didn't respond to my email asking how to get updates on my order (Bikebandit is great about this) they did ship quicker than I expected and my parts arrived Christmas Eve! Wahoo! Slow, but acceptable given the price advantage. Just wish they communicated better.

So with another 4-day weekend coming up I should be able to carve out the time I need to...

1. Replace my leaky fuel petcock
2. Replace those airbox boots with fresh squishy ones
3. Seal up the airbox
4. Finally adjust my valves

The valve adjustment logistics will be the trickiest part, since I'll need to measure first, then go buy shims because I have no shim set. I'm going to try out Steve's spreadsheet, which will at least make it easy to track what I need and get my shopping list straight.

[TheCafeKid]

Get your shims when the time comes from z1..they ship SUPER quick..i have ordered from them about 5 times now, never took longer than 3 days, and even that was over a weekend.

As an aside...i just got done watching the original starwars on hbo..i forgot how good that movie was...i also forgot how cheesey the dialog is...acceptable cheese however..lol

[Roostabunny]

Get your shims when the time comes from z1..they ship SUPER quick..i have ordered from them about 5 times now, never took longer than 3 days, and even that was over a weekend.

As an aside...i just got done watching the original starwars on hbo..i forgot how good that movie was...i also forgot how cheesey the dialog is...acceptable cheese however..lol

Hmmm, maybe I can pull that off via mail order. I found one local shop on my side of Phoenix that has 29.5mm shims around. It’s closed Mondays so I gotta get whatever I’m getting by Saturday cause I’m sure they’ll be closed Tuesday for New Years. My used parts place is also closed on Mondays – what’s up with that? Either way, I’ll probably have to drive the grocery-getter to work for at least one day.

I suppose getting into the valves won’t be as much of a pain once I get that fuel petcock taken care of. I’ve gotten pretty adept at it, but the juggling act of swapping the fuel line for the piece of crimped tubing I use as a plug is still a pain. I bought some fresh new 5/16” line to replace my aging fuel line, too. It’ll be nice to know I don’t have to think about that valve for another 25 years.

As for your aside, I’ve seen those original Star Wars movies more times than I care to admit, but it’s been quite a while. The cheese (especially combined with Mark Hamill’s terrible acting) is definitely part of the charm. Han Solo has always been one of my heroes and the Millennium Falcon is clearly the coolest ship in any galaxy. (Can you hear my geek accent coming out when I talk about it?) Anyway, it’s a long-time dream to have a vehicle worthy of the name. Not pretty and somewhat of a mechanical mystery at times, but always gets you there and FAST.

And since I’m doing my work myself I can hold to Solo’s follow-up to my signature quote which is, “I’ve made a lot of special modifications myself.” Actually, that last part’s even more true for you with all your custom work.

[TheCafeKid]

Watch your dealer, they sometimes gouge pretty good on shims. I couldnt find them around here for cheaper than 12 bucks each! ouch. z1 i think they are 5? maybe 7? either way still cheaper. and your dealer will most likely have to order them anyway.


Thats great kid...dont get cocky...

Prolly the best line in the movie..