bogs down and stalls if choke left on


Information and questions on GL1000 Goldwings (1975-1979)
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winguyjo
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Joined: Sat Aug 11, 2018 9:26 pm
Location: b.c. Canada
Motorcycle: wing1 : 1982 gl1100 interstate; resurrection complete. SOLD
wing2 : 1980 gl1100 interstate; resurrection complete. SOLD.
wing3 : 81gl1100i frame/82gl1100a engine/81cb900 bits. resurrection complete. naked. SOLD.
wing4 : 1977 gl1000 black w/ blue pinstripes; resurrection complete. SOLD
wing5 : 1977 gl1000 black w/gold pinstripes; nearly roadworthy when purchased, NOW RIDING.
wing6 : 1975 gl1000 blue; SOLD

bogs down and stalls if choke left on

Post by winguyjo »



1975 gl1000 ...

starts fine with full choke but will bog and die if choke left on for more than 10 - 15 seconds so startup consists of a dance involving part choke (will not start with just part choke) and some throttle twisting.
the bogging/stalling with choke on makes me think it's getting too much fuel (air cleaner is good; spark plugs are black but not sooty). engine runs fine when warm; great power, no stumbling.

any ideas ?


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winguyjo
Posts: 412
Joined: Sat Aug 11, 2018 9:26 pm
Location: b.c. Canada
Motorcycle: wing1 : 1982 gl1100 interstate; resurrection complete. SOLD
wing2 : 1980 gl1100 interstate; resurrection complete. SOLD.
wing3 : 81gl1100i frame/82gl1100a engine/81cb900 bits. resurrection complete. naked. SOLD.
wing4 : 1977 gl1000 black w/ blue pinstripes; resurrection complete. SOLD
wing5 : 1977 gl1000 black w/gold pinstripes; nearly roadworthy when purchased, NOW RIDING.
wing6 : 1975 gl1000 blue; SOLD

Re: bogs down and stalls if choke left on

Post by winguyjo »

well, i found what may, at least partly, explain the funky choke on this bike.
the before picture turned out blurry and now it's too late for a re-take, but if you look dead-center in these pics, you will see a tiny spring on the end of the choke linkage. it had been installed on the wrong side and was causing the linkage to contact the body of the carburetor, causing erratic movement of the linkage.

the engine, and the ambient temperature are both too hot now to do a cold start so will check it in the morning but something still doesn't seem right about movement of the choke assembly. i was told by the seller that the owner before him claimed this set of carbs was re-built; perhaps there's another mistake to be found somewhere. i did find that they were quite a bit out of sync and i now have that pretty much squared away ... this was my first ever carb sync so it's not perfect but definitely impoved from what it was.




cfairweather
Posts: 64
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Location: Cheyenne, WY
Motorcycle: 1975 GL1000, 1976 GL1000, 2013 BMW R1200RT, two restored 1971 K1 CB750s, 2019 Triumph Speed Twin
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Re: bogs down and stalls if choke left on

Post by cfairweather »

The pilot jets may be part of the problem. These are the air jets inside the 4 brass elbow fittings. Pull off the 4 rubber hoses and remove the jets. You can do this without removing the carbs. Make sure the jets are clean and the correct size. If the hole is too big, they will cause an over lean condition and if they are too small or dirty, they can cause an over rich condition. The best size hole for the 755A carbs is the size of a #62 drill bit. I simply drill out size 60 air jets with a #62 bit to get the jets to this size.

Read about the "off idle" issue here: https://www.randakksblog.com/how-to-cur ... flat-spot/
User avatar
winguyjo
Posts: 412
Joined: Sat Aug 11, 2018 9:26 pm
Location: b.c. Canada
Motorcycle: wing1 : 1982 gl1100 interstate; resurrection complete. SOLD
wing2 : 1980 gl1100 interstate; resurrection complete. SOLD.
wing3 : 81gl1100i frame/82gl1100a engine/81cb900 bits. resurrection complete. naked. SOLD.
wing4 : 1977 gl1000 black w/ blue pinstripes; resurrection complete. SOLD
wing5 : 1977 gl1000 black w/gold pinstripes; nearly roadworthy when purchased, NOW RIDING.
wing6 : 1975 gl1000 blue; SOLD

Re: bogs down and stalls if choke left on

Post by winguyjo »

well, i wound up taking the carbs out, and judging by what i saw inside the float bowls, they must surely have been cleaned in the not-too-distant past.
the only things that i found that were not quite right was a somewhat damaged o-ring on one of the jets (which COULD have been my own doing), and 1 of the floats was set about 2mm too low. all i did was re-set that float, replace the damaged o-ring, make sure that the jets were clear ... they were ( i didn't want to risk removing the pressed-in jets ) and make sure that the choke plates were opening/closing properly ... they were. sprayed things out with carb cleaner and compressed air. end result : the choke is now working properly.

i do have another running issue however. here's the problem ... if i sit long enough at a traffic light with the brakes applied, turn signal on, and the fan kicks in, the engine will gradually run worse and worse until it finally stalls. it will immediately re-start and will stay running if i give it some extra throttle. my idle is set at 1200 by the way. after checking the stator, cleaning all electrical connectors, cleaning and checking spark plug gap, i finally decided to swap batteries between this bike (1975 gl1000 with a brand new but cheapish china battery) and my 1977 gl1000 with a newish napa AGM battery. putting the AGM battery into the ' 75 seemed to solve the idle stalling issue but putting the cheapish china battery into the '77 did NOT cause a stall on that bike. what do you make of this ?

perhaps worth noting ... the stalling '75 has a dyna s ignition, age unknown and stock coils. the non-stalling '77 has points. did i read somewhere that the dyna s requires different coils ???

thanks for any help you can give.
joe
cfairweather
Posts: 64
Joined: Mon Jul 10, 2017 2:00 pm
Location: Cheyenne, WY
Motorcycle: 1975 GL1000, 1976 GL1000, 2013 BMW R1200RT, two restored 1971 K1 CB750s, 2019 Triumph Speed Twin
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Re: bogs down and stalls if choke left on

Post by cfairweather »

The fan definitely draws a fair amount of power from the battery and the voltage will drop a bit. The Dyna draws more power than the standard points setup. I have installed many of them and highly recommend replacing points with the Dyna S system. I also recommend replacing the standard coils with the Dyna 3 ohm coils because you can eliminate the ballast resistor. From what you have described, the high quality battery "solved" the problem, but I suspect you have some other issues too. The purpose of the ballast resistor is to prevent the coils from getting too hot by dropping the voltage going to the coils. The ballast resistor probably gets hotter when the fan kicks on and it could be breaking down. The reason I bring up the ballast resistor is because you said the bike will start right up after it dies. When you press the start button on a GL1000, the ballast resistor is bypassed which provides the coils with the full power from the battery. You also said that you rev it to keep it running and this may be because the voltage goes up when you rev it. In addition, you may have some marginal connections. Clean all ground connections including the main battery ground to the engine and frame. Also clean the frame and coil mounting connections and all other coil related bullet connections including the black wire with a white stripe (coil power wire). The ballast resistor connections should also be cleaned. Replace the old dog bone fuse near the battery with a modern fuse. Buy the Dyna coils with the Dyna spark plug wires and caps. Getting rid of the ballast resistor will allow the coils to operate at full power all the time. Then, put the cheap battery back in and see what happens.
User avatar
winguyjo
Posts: 412
Joined: Sat Aug 11, 2018 9:26 pm
Location: b.c. Canada
Motorcycle: wing1 : 1982 gl1100 interstate; resurrection complete. SOLD
wing2 : 1980 gl1100 interstate; resurrection complete. SOLD.
wing3 : 81gl1100i frame/82gl1100a engine/81cb900 bits. resurrection complete. naked. SOLD.
wing4 : 1977 gl1000 black w/ blue pinstripes; resurrection complete. SOLD
wing5 : 1977 gl1000 black w/gold pinstripes; nearly roadworthy when purchased, NOW RIDING.
wing6 : 1975 gl1000 blue; SOLD

Re: bogs down and stalls if choke left on

Post by winguyjo »

thanks, great feedback !

a couple of things ... this bike is not a keeper, so not sure that i want to shell out the money for dyna coils. if i can't cure it i will likely just sell as-is.
connectors are definitely not an issue as i removed the coils and cleaned all the connections as well as the battery connections, frame ground, etc., etc. (as i type this, it occurs to me that i haven't cleaned the fan connectors, so i will get on that).
i wish i had thought to swap out the ballast resistor while i was in there, is there a resistance value to check for on a ballast resistor ? i haven't been able to find any in my FSM.
User avatar
winguyjo
Posts: 412
Joined: Sat Aug 11, 2018 9:26 pm
Location: b.c. Canada
Motorcycle: wing1 : 1982 gl1100 interstate; resurrection complete. SOLD
wing2 : 1980 gl1100 interstate; resurrection complete. SOLD.
wing3 : 81gl1100i frame/82gl1100a engine/81cb900 bits. resurrection complete. naked. SOLD.
wing4 : 1977 gl1000 black w/ blue pinstripes; resurrection complete. SOLD
wing5 : 1977 gl1000 black w/gold pinstripes; nearly roadworthy when purchased, NOW RIDING.
wing6 : 1975 gl1000 blue; SOLD

Re: bogs down and stalls if choke left on

Post by winguyjo »

UPDATE :

bike sold, new owner can deal with the issue of stalling at idle. thanks very much for the help.


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