Did I break it again? Popping after cleaning.

[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..

 

[Roostabunny]

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..

Drat! Bummer of an update... well, partly.

The bad news is that locally or at Z1, no one has all of the sizes I need. Fortunately, one local dealer has the one size (2.60mm) that Z1 doesn't have, but I'm paying shipping and driving to the shop to boot. My buddy has a bunch of shims around but they're from Yamahas and Kawasakis - and I just found out they're 29.0mm instead of 29.5 diameter.

Anyway - I'll get that airbox sealed up tomorrow and the new boots on it. Then change my gear oil and replace my fuel line and petcock while I'm waiting for shims.

How 'bout...

"watch this..."

"Watch what?"

Cheers

 

[TheCafeKid]

Drat! Bummer of an update... well, partly.

The bad news is that locally or at Z1, no one has all of the sizes I need. Fortunately, one local dealer has the one size (2.60mm) that Z1 doesn't have, but I'm paying shipping and driving to the shop to boot. My buddy has a bunch of shims around but they're from Yamahas and Kawasakis - and I just found out they're 29.0mm instead of 29.5 diameter.

Anyway - I'll get that airbox sealed up tomorrow and the new boots on it. Then change my gear oil and replace my fuel line and petcock while I'm waiting for shims.

How 'bout...

"watch this..."

"Watch what?"

Cheers

You serious?? What size do you need? Z1 has shims from 3.0 all the way down to 2.3

Here my friend...
http://www.z1enterprises.com/catalog.aspx?pid=GS750B-1977-EN1

Minus the holiday i promise you'll get them at LEAST as fast as the dealer, prolly faster and you wont get gouged for em....

 

[Jd Powell]

Roostabunny, I am also in Phoenix (19th ave & 101) if ya need a hand feel free to PM me. I frequently spend my weekends wrenching/tuning and have a fairly well stocked garage. I've also been trying to get some of us Phoenix area GS'rs together for some group rides.

 

[Roostabunny]

Roostabunny, I am also in Phoenix (19th ave & 101) if ya need a hand feel free to PM me. I frequently spend my weekends wrenching/tuning and have a fairly well stocked garage. I've also been trying to get some of us Phoenix area GS'rs together for some group rides.

Hey JD, I'm around Arrowhead - Union Hills and the 101. Just replied to you in the "Sportbike Illiterate" thread, too.

I'll send you a PM.

 

[Roostabunny]

You serious?? What size do you need? Z1 has shims from 3.0 all the way down to 2.3

Here my friend...
http://www.z1enterprises.com/catalog.aspx?pid=GS750B-1977-EN1

Minus the holiday i promise you'll get them at LEAST as fast as the dealer, prolly faster and you wont get gouged for em....

Oh they had all sizes on the website, just not all in stock. They're fresh out of 2.60mm.

Anyway, I ordered the ones they had, and JD sent me the number of a local shop I didn't know about that does a lot of work on older Suzukis.

 

[Roostabunny]

[SIZE=-1]BTW, all my clearances were .003" and under. I'm pretty excited to see how the bike runs with spec clearances and a well-sealed intake path.

Meantime, while waiting/searching for shims I also replaced my fuel petcock and ancient fuel line. Aside from the obvious mechanical and safety benefits, it sure is convenient to have a tank that doesn't spew fuel whenever it's disconnected. I'm also planning to change the gear oil while she's sitting in the garage.
[/SIZE]

 

[Roostabunny]

BTW, I sure got confused between metric/English clearences (.003” compared with .03mm) and messed up Steve’s spreadsheet by entering .003 thousandths of an inch instead of 3 thousandths of an inch. The effect was that it seemed like all my clearances were in the millionths of an inch, and, of course, that meant I needed 8 shims when in reality .003” is well within spec. The spreadsheet works great when you follow the directions, and when I re-entered the measurements properly I only needed one shim which I was able to swap at a local shop for $0. I guess I’ll hang on to the ones I ordered from Z1 for future adjustments.

OK, the big news is that the airbox work seems to have done the trick on the popping, lost power, slow idle, and occasional white smoke during warm up. As a bonus, between that and the new battery, starting is a breeze. I had been goosing the throttle to get it to catch, but this morning I used choke and no throttle and it caught the first time. Could be my imagination, but I think throttle response is smoother too. I feel like it got choppy on deceleration for a while now, and I think it’s back to normal.



pics here for the airbox hacking/fixup...




Thanks go to 49er for the tip about the breather galley thing. I didn’t even see that when I was cleaning originally, and when I ran the coat hanger wire through there I ended up with about two tablespoons worth of rusty gunk. Yikes! I sprayed a little PB Blaster up there after cleaning, hoping to slow the return of more rust. Based on the volume of crud it’s likely that the breather was restricted, and I’m hoping my oil seals will get a nice break now that the breather can once again, well... breathe.

I struggled with getting the airbox back on, but only for about 3 minutes. After all I’d read about the magic moment of reassembling the airbox to the carb with new boots, I knew something had to be wrong. I’d installed left and right boots “Letter Up” as advised in this forum, but trying to get them hooked up made me think maybe that was backwards, since two boots on one side went fine and the other two were visibly not aligned. Upon closer inspection, I noticed that there was a Braille-like raised dot on the flange of each boot. Then I noticed four identical raised dots on the airbox – one under each hole. Those clever engineers! I spun the boots “Letters down” to align the dots, tried again on the carbs, and got to experience my own “magic moment” when they popped right on.

Anyway, a successful fix, and in the meantime I adjusted my valves, replaced my fuel petcock and fuel line, and changed my gear oils (None too soon on that gear oil – they looked pretty yucky. And I made a mess despite Basscliff’s great pictorial). Next step – carb rebuild!

Thanks fellas!

 

[Flyboy]

Glad to hear she is running sweet again, good job.\\/

 

[49er]

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.

The film of oil that was forming on the outside of the airbox is caused by the pressure build up in the engine when the breather tract in the airbox isn't working correctly. When the crankcase can't breath, oil gets forced past the seals in the cam chain tensioner, the oil pressure sensor unit next to the starter and the tacho drive unit in front of the engine. When the tract gets completely blocked, your engine will also start to lightly smoke, through oil being forced past sad old oil rings. Ask me how I know!

 

[Roostabunny]

The film of oil that was forming on the outside of the airbox is caused by the pressure build up in the engine when the breather tract in the airbox isn't working correctly. When the crankcase can't breath, oil gets forced past the seals in the cam chain tensioner, the oil pressure sensor unit next to the starter and the tacho drive unit in front of the engine. When the tract gets completely blocked, your engine will also start to lightly smoke, through oil being forced past sad old oil rings. Ask me how I know!

OK well, time to go to the carwash again - that way I can be sure what's coming from where. I've changed seals in the cam chain tensioner and tach sender and installed new cam cover, half moons, and breather gaskets, so hopefully clearing that breather will keep my engine a little cleaner a little longer.

That's one of my favorite things about this forum, we get to learn from each others mistakes and sad old smokey ring sob stories! As a newbie mechanic, it sure makes it a lot more fun when I have all this experience at my fingertips. :-D