Need Some Help on Carbs

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82gl1100iwingman

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I just rebuilt some carbs on a 77 GL1000. I have the carbs back together and on the bike. It starts, runs and accelerates fine with no load. While I was trying to sync the carbs, the bike had a hard time idling below 2000 rpms. It like to die below that and when it did, it would belch oil out the crankcase breather drain tube. There is no evidence of oil in the air filter box so it must be coming from the pvc valve. While I had the carbs out I looked down into the intake chamber and noticed lots of oily carbon on the valve. I am assuming this generally normally from the bike always being on the side stand. It did smoke a lot on start up but eventually cleared and ran clear out the left exhaust.

When I took the carbs apart I made the mistake and didn't pay attention to which air jet came out of which hole. According to the factory service manual the primary air jet is a #120 and the secondary jet is a #60. I ASSUMED the larger air jet so I put the larger jet in the secondary position. Another conundrum is the slow air jet is about the same size, so I am really questioning myself if I got all the right pieces in the right place and that this might be the culprit as to why I am getting the oil belching from the crankcase via the breather tube.

Any help would be appreciated
Thanks in advanced,
Brian
 
It does sound like you've mixed up the jets. I'm sure there will be a more knowing answer soon.
 
Bigger air jet, 120, goes on the outside, nearest the intake valve. It actually couples with the 62 primary jet, while the smaller air jet, 60, couples with the bigger main jet which is 120 and is the one with the needle.
 
I pulled the carbs back out and took the air chambers off. All the air jets are in the correct location. I pulled the float bowls and the primary and the secondary fuel jets were installed with the small orifice down (into the float bowl). I turned them around to where the small orifice is going up (into the carb). Also I have read the top of the air chamber can leak air if some the resin has broken off. I had one are chamber with some broken resin. I mixed up some epoxy and applied to top (outside) of air chamber. Bench sync'd the carbs. All butterflies are set to 30.45mm from edge of carb. Waiting for epoxy to dry then I'll will reinstall carbs. Hopefully this will fix the running and not able to adjust carbs problem. If so and bike continues belch oil, that is a different problem that the owner can address himself.



Ok, I have reinstalled the carbs and it still won't idle below 2000 rpm's and still belching oil out crankcase tube. With bench sync of carbs, carbs are perfect as far being equal within .25 in/hg of each other but only running 5 in/hg of vacuum at 1000 rpms. It has 15 in/hg of vacuum on all 4 carbs running at 3000 rpms. The vacuum stays consistently equal on all four carbs as the bike is revved up. While carbs out and float bowl off rechecked float level, they are all at 20mm and they are working properly. Sprayed ether around manifolds for air leak, no air leak found. Did a compression check, 150 psi in each cylinder. Motor has not been running long in my presence (a little over three warm up cycles) so I am not sure of how long the spark plugs have been in the motor but the plugs are #1, covered with white ash, #2 black carbon fouled, #3 black carbon fouled, #4 red. Bike has electronic ignition so no problem with points/dwell. I'm now starting to think there is a problem with the ignition, like retarded timing, or am I just being retarded?
 
Have you done a valve adjust? I guess first you should check timing belt marks, then ignition timing, then a valve adjust. High idle is usually from an air leak, but can be from throttle plates being set too high. They are supposed to leave one of the three small idle holes open. If your plate is open a little too much, the motor can pull fuel from all three holes instead of one. I would check the other items above before chasing the high idle.
 
Check the belts are correctly installed and neither is a tooth off. Check the ignition mechanical advance. The weights and lobe need to move. I've had one rusted solid. It's sounding to me more like a timing problem now. Or possibly a low voltage condition affecting the ignition.
I agree also the oil level may be too high. From filling while on the side stand perhaps or fuel getting into the oil.
 
The only way carburetion could be causing oil being forced out would be if the float needle valves are leaking and filling the engine with gas. Is the oil that comes out normal, or does it have a gassy smell?
 
yes steve 83 is right on if gas is leaking in motor oil will come out of crankcase breather nonce it get full ... this is quite common on oldwings they useally don't leak other places and fill up crankcase qick
 
The oil doesn't smell like gas and considering I just rebuilt the carbs and pulled the carbs out a second time to double check my work and verified the floats were working properly, it would rule out the floats stinking open.

The owner of the bike needs to decide if he wants to spend anymore money on it before I do anything else.
 
Have you replaced the spark plugs? I have seen where previous or current owners have cleaned them with a wire wheel and causes all sorts of misfire problems. If not try swapping the black plugs where the white and red are and see if the problem follows the plugs or stays the same.
 
Plenty of good ideas folks!

My question is simple: Where does your crankcase breather hose go? I've never worked on a '77 gl1000, and don't have its manual. If is goes to a breather bottle, is that bottle full, meaning the crankcase can't really "breathe?" If it can't vent off air pressure from even minimal blow-by, then your crankcase becomes a balloon! :shock:
 
That's a good idea to check. The 77 exits on the left rear, goes to a "puke" tank on the right rear, then up to the air cleaner. Lots of people leave the top into the air intake open so it doesn't soil the filter.
 
Sorry I am late to this thread. Oil spitting out the crankcase breather?? That is excess oil in the system. How much oil is in the engine? That breather only gets wet if there is excessive blow-by (or the breather tank is full of water).
 
For those that have been following this thread, I thank everybody for your advise and help.



I found the problem. I got another pair of intake manifolds that are good and installed them on the bike. No change in the vacuum, still at 5 in/hg indicating a manifold leak. Instead of just "spraying" ether all over the manifold, I used a straw on the can of ether this time. I gently sprayed all the boots and there was no leak. I sprayed the #2 intake were it mounts to the head, no leak but I did get a little overspray by the head and block. The engine revved up. I then sprayed directly and the joint of head and block and the engine took off like a twisted the throttle. Tried the #1 side at the head and block, the engine once again raced like I twisted the throttle.



So it a appears the head gaskets are blown, or the head gasket material is just "weathered away", allowing exhaust gases to get into the crankcase causing to much pressure and blowing the oil out the crankcase breather tube and the head gasket is allowing unmetered air into the combustion chamber making hard to adjust the carbs. Now to find out if the guy wants to spend anymore money on this bike.
 
wow ive seen and posted about conditions of head gasket that just sit and rott ... and it seems antifreeze nas the worst effect on the head gaskets


great move by the way ... that's really using the I b me to the max this will not be forgotten here :mrgreen:
 
Curious - if ether can enter the combustion chamber through the head gasket, then combustion gasses would be able to exit the same way. Compression on that cylinder would be low, and you would hear the leak - I would think... I would trickle water over the block/head joint while running and check for bubbles, or see if it gets sucked in.

The only way for exhaust gasses to enter the crankcase would be through the head into the valve train area, or a blown head gasket at the bottom of the head, into the oil return.

The ether might be getting pulled into the plenum past a bad o-ring, or into the carbs through worn throttle or choke shafts. Many possibilities here...
 

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