Carb sync and valve adjust-still not too happy

[Ranger]

If you remove the plastic piece that is the filter completely, keep in mind you're going to lose your reserve as well.

 

[1948man]

http://www.thegsresources.com/_forum/showthread.php?t=168187&highlight=breather+hole

Last post in the above thread would seem to doubt that the vent hole is a factor but I guess that has been ruled out anyway.

 

[robertbarr]

Robert, are you suggesting that I remove the screen from the plastic skeleton completely, while leaving the skeleton attached to the petcock?

That's what I did to mine, and it solved my problem. Of course, it leaves you pretty much unfiltered. There are usually tiny filters on top of the inlet seats, but I think those were intended to be a 'last resort' protection.

That opens the 'auxiliary filter' can of worms, but that's another topic.

 

[Steve]

That's what I did to mine, and it solved my problem. Of course, it leaves you pretty much unfiltered. There are usually tiny filters on top of the inlet seats, but I think those were intended to be a 'last resort' protection. ...

I don't think the VM carbs have those little filters, do they? :-k

I have only done a couple sets of them, but don't remember seeing any.

.

 

[Suzuki_Don]

I don't think the VM carbs have those little filters, do they? :-k

I have only done a couple sets of them, but don't remember seeing any.

.

Steve, he has CV carbs on the bike going by the pics in his first post, but we don't really know for sure as no-one has mentioned what bike it is that is being worked on.

The other issue I am a bit concerned about is the excess shim clearance on exhaust #2, up to .5mm. Others are talking about a stuck bucket, but if this was the case it could only be stuck up which would create less clearance to the cam lobe. The bucket can only go down as far as the valve stem will allow it, unless the valve springs are broken which has been mentioned before. Also it has been mentioned that there is a lot of white smoke out of the #2 exhaust pipe (is this a coincidence).

I think a compression test is in order. Remember the old rule, don't start adjusting carbs and looking for fuel problems until the engine is in mechanically A1 order first.

 

[tas850g]

When I dipped my vm's I don't recall any screens.....but maybe I missed them.

Waiting to see if by running the bike with the petcock on pri will make a difference.

 

[Tom R]

Also, make sure your fuel line isn't getting kinked when everything is put back together.

 

[kdo58]

I had a similar problem, it ending up being a small piece of rubber from the fuel hose, I would take the carbs off and check the fuel bowls and did not see any thing.
I finally took them completely apart, and the small piece of rubber would move back and forth between different carbs in the transfer tubes between the carbs. It was stuck behind the float needle seat.

 

[ssanderson111]

The bike is an '81 650 G. Carbs are CV

When we first check the #2 exhaust clearance, we got less than .04mm. We changed the shim accordingly. With the new shim in place, the reading was over .5mm! The bucket was visibly not returning at high as it should be. We left the appropriate shim in and started the bike up after adjusting all of the other clearances. The engine was noisy as heck at first, but as it warmed up and we gave it some revs the noise went away. Also, when using the tappet tool, the bucket applied resistance as it was depressed...

The fuel line isn't kinked at all. I doubt there is anything obstructing the fuel connections between carbs as I had them apart and cleaned a few weeks ago.

I'll be able to see how it runs with the petcock on "pri" tomorrow and will update you asap. Thanks again for your help! Keep the suggestions coming!

 

[kdo58]

The fuel line isn't kinked at all. I doubt there is anything obstructing the fuel connections between carbs as I had them apart and cleaned a few weeks ago.

I had just cleaned mine.

 

[ssanderson111]

In that case, I'll double check them. : )

 

[gert du prez]

had the same issue after valve adjustment and carb synch (did it with petcock on PRIME)

2 reasons caused this:

1) replacement vent hose was too wide (and sucked small amount of air apparently) --> replaced with smaller hose
2) petcock is not working properly: 'ON' didn't work before either (but I drove on RES constantly), now ordered replacement petcock as well to really start from scratch

what I learned from Mr. Steve: it is not because you suck on the vacuum line (attached on the petcock) and you feel you can move the diaphragm, that in practice the fuel will flow when everything is installed !

 

[DrImodium]

I had a similar problem with my 80 GS1000 with the vacuum operated petcock. Pull your #2 plug, what does it look like? Me thinks its the petcock.

 

[ssanderson111]

UPDATE: I just put another gallon of gas in the tank, turned the petcock to "pri", and started the bike. It started right up with choke half out. It idled fine, but I noticed a small amount of white smoke coming from both exhaust pipes. After the engine was warm I putted around the parking lot a few times (3-4 .25 mile laps). It seemed to be running MUCH better. First gear seemed a little sluggish below 4k rpms. Then I took it out for a quick 5-mile ride. It accelerated nicely and didn't seem to exhibit any of the symptoms previously discussed. Although, it did feel a little funny in 2nd and 3rd gear above 7k rpm. The engine is still louder than it was prior to the valve adjustments as well.

My new petcock should be here in 2 days. The airbox boots should be here by Saturday. I'm guessing the carbs will need to be synced with the new boots on?

 

[tas850g]

It was very frustrating for me trying to figure out what the heck was going on when my bike acted like this after the carb cleaning. Long story short, I put the petcock on pri and it ran great. I couldnt have been more excited!

Now on to the next task.

 

[Guest]

Funny you should mention that it seemed louder. I have noticed over a period of time ( because it took a long period of time to get mine sorted out) that the better they run, the quieter they get.

 

[BassCliff]

Hi Steve,

It will be a little noisier because some of the valve clearences are on the loose end of spec, one or two @ .10mm. Does #2 still make the tapping sound? But your news is encouraging. We can sync the carbs again after the new boots. Did you get a new petcock too?

Thank you for your indulgence,

BassCliff

 

[ssanderson111]

Thanks for your help, guys!

Cliff- The new petcock arrived yesterday! The boots are taking longer than expected to get here...probably had to be ordered from Japan. I'm waiting for the boots to get here so I can put them on at the same time as the petcock.

The good news is I've ridden the bike 15-20 miles over the last couple days and it's still running consistently!

 

[Suzuki_Don]

Thanks for your help, guys!

Cliff- The new petcock arrived yesterday! The boots are taking longer than expected to get here...probably had to be ordered from Japan. I'm waiting for the boots to get here so I can put them on at the same time as the petcock.

The good news is I've ridden the bike 15-20 miles over the last couple days and it's still running consistently!

Steve be careful you keep plenty of fuel in the tank as running on PRIme you don't have any reserve and you don't want to get stuck miles from home with an empty tank.

Good news about the bike running well. I'd check #2 exhaust shim again and try to get it within spec. for a quieter motor.

 

[ssanderson111]

Steve be careful you keep plenty of fuel in the tank as running on PRIme you don't have any reserve and you don't want to get stuck miles from home with an empty tank.

Good news about the bike running well. I'd check #2 exhaust shim again and try to get it within spec. for a quieter motor.

I was thinking the same thing! I put another gallon of gas in the tank today...