New to GS, a couple quick questions...

[Guest]

Some of you may have been following my introduction last week. I purchased a '79 GS750N from my neighbor. Long story short, wasn't running (hadn't been started in 4 years), no power, nothing. Got power to it the next day (everything worked), changed oil, fresh gas, checked compression, checked spark on all 4 plugs, and FIRED IT UP. Started up with no problems at all (sounds amazing with the Kerker exhaust). Choke on, runs steady. Choke off, low idle until stall. Carb o rings and gaskets are on the way along with intake o rings. I'll clean the carbs thoroughly and I'm sure I'll have it purring in a couple days.

I do however have a failed stock petcock. On prime, all fuel feed is good, but when switched to "ON" or "RESERVE", it'll run for another minute and starves. No big deal, the diaphram is shot. My question... since the OEM petcock for my '79 is now $100, I'm thinking of just going with a Pingel. Same price for the Pingel and the adapter plates as is an OEM. I am curious if anyone out there has fitted a Pingel to a '77-'79 750N or 750E or whatever other models share this same tank? Only worried that the fuel feed stalk may be too tall to fit inside the tank. I heard they were pretty tall. I've searched this forum for hours and only found folks mounted Pingels to 850's and 1100's. One gentleman had the clearance issue on his '80 750L, but that has the teardrop tank.

Question 2: I also took the Cam covers off to check valve shim clearance. My smallest feeler gauge is .037mm and it would not get thru any shim. The good news is, there is no metal to metal contact when turning over the motor, so they shouldn't be contacting the pistons. The tappet depressor tool is on order so I can get the shims out to see what size is in there now, but I'm not going to have any reference as to what size I'm going to need to make the correct gap. Am I stuck just purchasing a few varied sizes to use as testers? I'll try to clean all the oil out of the cam area so I can see if there is any clearance at all. Sorry for my lack of knowledge in the valve clearance department, but I've never had to deal with this before. Any suggestions would be greatly appreciated. Very much looking forward to getting this bike on the road. After I get it tuned just right, I'll start the build.

Photo of the project...

[azr]

Glad to hear you're making progress. Sorry no advise on the Pingel but sure have heard they are bolt in and forget about them for years, just don't forget to shut them off. As for the shims you can do the shim job right now if you have some long zap straps. There's a how to on Cliffs site about using zap straps do a shim adjustment. The tool is a bit easier for sure but the zap straps work just as well. No need to worry about your feeler gauge. If you find one that is below 0.037 I doubt it'll be much lower. If it was 0.02 the next shim would be 0.05 bringing it up to 0.07 anyways. If it was actually 0.01 the 0.05 shim would bring it to 0.06 ect... All within the specs of 0.03-0.08. You could check all your shims right now and then you could order what you need. Remember, once you have all the measurements you can sometimes swap shims around to makes the clearances within spec., it can just save you a few bucks that's all.

[Big T]

The "not idling" is the classic result of tight valves

Get your valve spread sheet from Steve and inventory your valves

Yes, you may need a extra skinny shim to measure your way around the motor.

Let me know what your thinnest shim is and I can check to see what I've got in my stock of shims

On the petcock, are you sure the vacuum doesn't work? The line may be broken, or attached to the wrong place

[tkent02]

Petcocks can be found cheaper than that. Try here:

http://www.z1enterprises.com

CAll them, they are real people.

[Steve]

The "not idling" is the classic result of tight valves

Actually, "tight valves" would more-likely prevent it from starting in the first place.

"Not idling" is probably clogged passages in the carbs.

Get your valve spread sheet from Steve and inventory your valves

Yep, the info is right down there.

Yes, you may need a extra skinny shim to measure your way around the motor.

Get something like a 2.40 or 2.30, then measure all the EXTRA clearance, you will soon see what shim you need in that location.

On the petcock, are you sure the vacuum doesn't work? The line may be broken, or attached to the wrong place

Good advice. Another thing you can do is to open up the petcock to make sure the plunger that seals it is not stuck. There is not enough force available from engine vacuum on the diaphragm to release a stuck valve. You might have to free it up, then it can do its job.

Regarding the OEM vs Pingle: for the same money, I would DEFINITELY go with OEM.
Yeah, the Pingle might work, but you won't know until you get it to see if it will fit. Then you will have to remember to turn it ON and OFF every time you ride. Sorry, but I am getting lazy in my old age, that is just one thing that the bike can do for itself.

.

[Drewbis1]

Thanks for the quick responses. I'll head out to the garage and see if I can get some zip ties in there to get shims out. As for the petcock, I'll get it apart and check it out. Just hope I don't create and leaks, because it's not leaking at the moment. As for lines... I'm trying to source some new rubber fuel and vacuum lines. Mine are rock solid, not flexible at all. I don't doubt they are not sealing properly or have a crack in them. The vacuum lines I can find at auto parts stores, but rubber lines to be compliant with fuel are harder to source locally.

[tkent02]

Go with the Suzuki fuel and vacuum lines, they fit really well. You won't cause any leaks, petcocks are really simple to open up.

[Charlie G]

I've found fuel lines a local independent, non dealer M/C shops that source non-OEM parts from Parts Unlimited. They have a plastic hose that is clear blue green that hooks up well, in the right sizes and aren't as bulky as the auto parts suppliers rubber ones. I'd stick with the OEM style petcock from Z-1. Z-1 is a great supplier.

cg

P.S. Take Big T up on that offer of a loaner shim....but lock the fridge

[Crankthat]

Do not have your answers but I sure do like that bike!

[jsandidge]

keep a shim in the bucket

As you check the size printed on the bottom of each shim, make sure to put it back in before you move on to the next one. If you turn the cams with no shim in the bucket, you will damage the cam lobe or the bucket.

[Drewbis1]

As you check the size printed on the bottom of each shim, make sure to put it back in before you move on to the next one. If you turn the cams with no shim in the bucket, you will damage the cam lobe or the bucket.

Damn, wish I read this before running out to the garage. I only moved a couple around before I noticed it was rubbing on the bucket. I inspected them all and no damage. Had to shut down production for the day though, until I get my shims from Z1. On a positive note, I did get inventory of all the shims, and I had time to get 2 of them dialed in. 7 out of the 8 were 2.7-2.8 so I ordered a few 2.6's and 2.65's thinking they are going to be dropping no more than 2 sizes.

Again, thanks everyone for the advice, tips, courage, motivation. I love my Aprilia, but this $400 bike has all of my attention at the moment. And I havn't even ridden it yet.

While I wait for the shim tool, shims, and gasket, I can still bleed the brakes, re lube the tach cable (was slow to react when I started it), do the same to the speedo (started SCREAMING just from pushing it up the street), and get that chain cleaned and tensioned. Then clean the carbs when I get my gaskets and o rings, sort out the shims when they arrive, and hopefully I'll be riding within a couple weeks.

Now just have to find motivation to go to work 60-70 hours per week.

[Paul]

Damn, wish I read this before running out to the garage. I only moved a couple around before I noticed it was rubbing on the bucket. I inspected them all and no damage. Had to shut down production for the day though, until I get my shims from Z1. On a positive note, I did get inventory of all the shims, and I had time to get 2 of them dialed in. 7 out of the 8 were 2.7-2.8 so I ordered a few 2.6's and 2.65's thinking they are going to be dropping no more than 2 sizes.

Again, thanks everyone for the advice, tips, courage, motivation. I love my Aprilia, but this $400 bike has all of my attention at the moment. And I havn't even ridden it yet.

While I wait for the shim tool, shims, and gasket, I can still bleed the brakes, re lube the tach cable (was slow to react when I started it), do the same to the speedo (started SCREAMING just from pushing it up the street), and get that chain cleaned and tensioned. Then clean the carbs when I get my gaskets and o rings, sort out the shims when they arrive, and hopefully I'll be riding within a couple weeks.

Now just have to find motivation to go to work 60-70 hours per week.

Are you sure your feelers are metric?? Quote.. "My smallest feeler gauge is .037mm" .... I have never seen one that size as part of a standard set check its not imperial... it should be like foil thick... Just asking?

[Drewbis1]

They are actually standard inch feeler gauges measured in thousandths of an inch. Below the .0015 .002 .003 etc they have the metric conversion. I measured them with my calipers to be sure. Though the smallest in the set are the .037mm, .076mm, then .102mm so I don't have much knowledge as to where they are in the spec. I did find these on Amazon. They will be about $12 shipped and have .02 .03 .04 etc. Might have to order them...

[Paul]

Ah I see, yep that set will do you fine. Good Luck!

[bomber737]

I love my Pingle and it fits perfectly on my 1000. If you call them they are very friendly and Helpful. They can help you find the correct one for your application. If you set your carbs up properly they should not leak fuel, even if you forget to shut the fuel valve off. So after you clean and or rebuild them be sure to make sure the floats are set properly and verify they shut off the fuel. I blow on the fuel line and turn them upside down. If you can hear air leaking they will leak fuel if you can hear no air leaking your good to go. I shut off my fuel as a matter of habit. I hate wasting cash on new pet cocks when you can buy a cheap Briggs and Straton fuel shut off valve for $3.50 put it in line and not worry about if your pet cock is wore out and leaking.