[b.pete]

imported post

I got my Randakk's kit the other day so I pulled the carbs for a cleaning. Seems as though the PO had them apart and didn't change any of the seals. They look pretty clean so far but I'm wondering how I can check the float bowls to make sure they don't leak.

I though about submerging them in a can of gas using weights to hold them just below the surface and see if they stay floating overnight. Could I do the same test with water (safer)?

Also is there any easy wayof bench testing the needle and seat. I know to inspect them and change them in pairs but I'd really like to know that they are going to seal without putitng the carbs back on the bike. I thought about using a 6PSI fuel pump I have to pressurize the supply passages but I'm not sure if that's too much pressure.

The carbs came off because the front two were leaking gas into the air box really badly. It would run across the air box floor and into the back two carbs. I assumed it was the fuel seals between the carb and the air box. Inspection of the two right side carbs shows the seals are there but old and hard so that is probably it. I just want to do what ever I can to keep from having to take the carbs back off.

 

[twisty]

imported post

b.pete wrote:

I got my Randakk's kit the other day so I pulled the carbs for a cleaning. Seems as though the PO had them apart and didn't change any of the seals. They look pretty clean so far but I'm wondering how I can check the float bowls to make sure they don't leak.

I though about submerging them in a can of gas using weights to hold them just below the surface and see if they stay floating overnight. Could I do the same test with water (safer)?

Also is there any easy wayof bench testing the needle and seat. I know to inspect them and change them in pairs but I'd really like to know that they are going to seal without putitng the carbs back on the bike. I thought about using a 6PSI fuel pump I have to pressurize the supply passages but I'm not sure if that's too much pressure.

The carbs came off because the front two were leaking gas into the air box really badly. It would run across the air box floor and into the back two carbs. I assumed it was the fuel seals between the carb and the air box. Inspection of the two right side carbs shows the seals are there but old and hard so that is probably it. I just want to do what ever I can to keep from having to take the carbs back off.

b.pete, you could test those floats like you stated. Probably should use gasoline or mineral spirits as water usually doesn't seep into as small of a crack as the ligher fuels & spirits do.

When you submerge the floats look for air bubbles to escape from a small crack or seam.

I usually just weigh each float on small gram scale & if one is found heavier than the others just replace it. Or if the bike hasn't been run in a while just replace the floats so I know I won't have any future problems as the floats heat up & expand while in usage.

On the needle & seats? I either use a My-Ty-Vac hand vacuum pump if handy & draw a vacuum on the needle/seats, or if no pump available place the needle in the seat then suck on the seat threads & while still holding suction on the seat stick the tip of my tongue over the threaded end.. If the needle/seat sticks to my tongue for a short while it is holding a good seal (if it falls right off you have a leaker). If you are using after market needle & seats look closely that the needle clip isn't contacting the seat with the needle all the way in the seat as that can cause a (poor or no) seal of the needle to the seat..



Twisty

 

[axelwik]

imported post

Turn the carb assembly upside-down and put some air pressure to the fuel inlet. If they leak down it could be the plenumO-rings you talked about or the float valves. Don't forget that there is a large rubber gasket between the halves of the plenum with fuel passages for the left two carbs, but you probably replaced it when you used the Randall Washington kit.

 

[axelwik]

imported post

My carbs are coming off today for the same problem.

 

[b.pete]

imported post

Well I haven't replaced anything yet. I pulled the carbs off last night, broke the air box in half, removed two carbs and torn one down. I was really surprised at how many jets are in there.

I like the vacuum idea I never thought of that. I have a vacuum pump so I'll try that one tonight on the one carb. I'm only doing one at a time so I have an assembled one to look at if I get confused and so I don't mix parts up. Mixing up jet between carbs is probably not a big deal but mixing up needle valves and thier covers and thier jetcould be.

 

[b.pete]

imported post

Tried the vacuum pump trick on the one carb I've got broken down. Was able to pull 20" with slight pressure on the plunger in the center of the needle. That should be about 10 psi (maybe a little less at my elevation ,2500ft)so I think that set is good. What a great way to check these:clapper:

Oh and we must have different carbs. My seats don't screw in. They are sealed by an oring and retained with a clamp. This is no surprise as this is a 78 and the smallest motor available so I'm sure the carbs have changed quite a bit over the years. What I do find weird is the carbs in my manual aren't quite the same as the ones on the bike. Not any big differences but differences just the same.

 

[gaswing]

imported post

Small differences inside the GL1000 carbs are normal, Honda tried to improve the poor running as the model evolved.

 

[b.pete]

imported post

Well I guess I jumped the gun assuming that the fuel passage seal had failed. When I got carb #2 taken apart I found the float bowl stuck. The pin was bent. I was able to get it straightened and dressed up so the float is operating freely now.

My manual says to set the float at 21mm from the raised section of the float bowl sealing surface. Should this be measured at the back (away from the needle and seat) or front of the float. I get about a 1mm difference between the two when the back is set at 21 mm. Maybe this 1 mm is inconsequential though.

I was at 22.5 before I set it and it was no fun task trying to bend out 1.5 mm.

 

[axelwik]

imported post

b.pete wrote:

Well I guess I jumped the gun assuming that the fuel passage seal had failed. When I got carb #2 taken apart I found the float bowl stuck. The pin was bent. I was able to get it straightened and dressed up so the float is operating freely now.

My manual says to set the float at 21mm from the raised section of the float bowl sealing surface. Should this be measured at the back (away from the needle and seat) or front of the float. I get about a 1mm difference between the two when the back is set at 21 mm. Maybe this 1 mm is inconsequential though.

I was at 22.5 before I set it and it was no fun task trying to bend out 1.5 mm.

Measure at the free end of the float... farthest from the pivot. The float needles probably have some small spring-loaded pins built-in. Measure float height without compressing these little pins. It's easiest to lean the carb assembly against something at an angle that doesn't compress the little pins, but with enough pressure to completely close the float valves.


It's important to get the float heights on a GL1000 as close as you can get to 21mm. Within 1/2 mm.

 

[b.pete]

imported post

Thanks for the info. I set it with the float resting on that pin. Looks like it was proabably off by more than 1.5mm. I'll reset it tonight before I continue with the other carb.

Man this takes a soft touch.

 

[b.pete]

imported post

Well it's midnight but the carbs are done. I flipped the assembly upside down and put a vacuum pump on the fuel inlet. Pumped it up to 25" and had no leaks. That's encouraging. I'm going to put it back on in the AM and start it up. I need to see if it will run well enough to take it for a ride.

I need to balance the carbs but firstthe timing needs to be checked and the plugs need to be replaced. All the throttle plates appear to be equal now so I don't think they it be too far off when it comes tme to balance. Hopefully I can get it running well so I can take it in and get the smog check done next weekend.

That Randakk kit is top notch. Whomever suggested it, thanks a bunch.

 

[axelwik]

imported post

Let us know how it goes once you get the carbs back on the bike...

 

[b.pete]

imported post

Well I started it with no air cleaner and it smoked like a bad dog. It was gray so I'm thinking oil. Oil level is fine don't really know what that is all about but it idled ok so I shut it down and went to putting everything back together.

The next time it started was after the ail cleaner was back in place and the crankcase vents hooked back up. No air filter.It stopped smoking and idled with no choke at 2000. I lowerd the idle speed to just over1000 and it idles kindof rough but it idles.

I've cleaned the plugs (they were covered in soot) and gapped them at .026. I'm going to take it out for a ride here shortly

 

[b.pete]

imported post

Well I took it for a road test. It ran pretty bad at the start but cleaned up as I went. I couldn;t go to far but I got it up to operating temp. It still idles a bit rough adn is running rich at times. The PO removed baffles and I can hear popping from the exhaust occasionally.

I think it will get better as it runs. I've got some pretty bad deposits on the intake valves that I'm hoping I can clean up with some fuel system cleaner. I also need to replavce the plugs and balance the carbs so it didn't run too bad considering.

I was able to open it up and run up to 70 a couple of times. The first time it didn't want to pull to the red line but the second time it did. It still will not take a load very well below 2K. I don't know if that's too much to ask this motor but I think it's related to the rough idle. Problems in the idle circuit I'm sure have an effect at part throttle when you're just coming up on the primary jet.

I'm also thinking the reduced back pressure with the baffles missing may require an other than stock idle screw adjustment. I may just adjust them like you do a car.

 

[axelwik]

imported post

I took mine for a ride today, the first time since putting the carbs back together. At first it ran real rough, but it cleared itself out and is now running better than it ever has. Nice smooth power, and at low speeds it pulls very smooth, evenfrom a stop.

Since you have a low-restriction exhaust you might have to do some re-jetting. I had to with mine... I'm running Harley Sportster mufflers.

Since fixing my plenum leak problem and re-jetting to match the mufflers the bike runs better than it ever has for me.

 

[b.pete]

imported post

Well I didn't want to hear that. Taking the carbs off is a real PITA. What jets are you running?

 

[axelwik]

imported post

Our carbs are different. The '77 and earlier carbs were bigger than the '78 and'79.

But here's what I did:

Raised the vacuum needles by about .020" by installing small washers under the heads of the needles. Be sure to put a drop of loktite on the barrel-shaped retaining screws that hold the needles in place, then loosen the screws enough so that the needles have the same amount of play they did before installing the washers. This flows more fuel up to about 3/4-throttle.

Installed smaller slow-air jets. These are the jets that screw into the brass elbows on the side of the carbs with the vacuum hoses. I went from a #110 to about #100. If you can't find jets that fit into the elbows you can always find an oversized jet that you can push into the vacuum hose. This flows less air at idle - richer mixture at idle and just above.

Replaced the #120 main air jet with a #110. (These used to be my slow air jets - they'll screw right in). The main air jet is one of the two jets under the kidney-shaped plate in the top of the carbs (outboard jet... it has the biggest orifice). Less air, higher ratio of fuel - richer all the way to throttle full-open.

You might not need to go this far since I don't think your '78 was jetted quite as lean as the '77 to start with.

Find out where your performance issues are, then go from there.

 

[b.pete]

imported post

Well that's not too bad. After doing some reseaqrch I know Honda calls them jets but I know them as air bleeds. I considered jets to be the one's in the float bowl. Anyway changing the air jets (seems like) can be done with just the air cleaner housing removed.

I need to pull one of the tops back off he carb anyway as I thinkg I mixed up the primary and secondary air jets. I put them back in how they came out but I'm thinknig that was wrong.

 

[axelwik]

imported post

Yeah,they're easy to mix up. Even the Clymer manual has them backwards. The Primary (largest orifice) needs to be outboard, toward the carb output/toward the head. (These are the two jets under the kidney-shaped plate.)

 

[b.pete]

imported post

Well I put it back together the way it came apart and that was a mistake. The PO had them in wrong. I was able to swap them with out removeing the carbs fromthe bike. I had to take off the air cleaner and the intake elbows had to be rotated 90 degrees but that's better than messing with the throttle cables again.

It runs much better under load but it doesn't want to idle below 1500 now.That may be due to the balancing though. I want to check the timing before I go any further so that's next weekends project. That gives me time to get something to balance the carbs and a helmet. I know, I know I shouldn't be riding without one but I needed to test what I had done.

Looks like my smog check will have to wait another week.