After essentially finishing my '78 GL restoration, I'm experiencing issues with the way it runs. It starts and idles nicely, but under load or hard throttle, it stumbles, bogs down, and doesn't pull like it should. Something is holding it back. It's a 15K mile motor, so hopefully it's nothing major internally. Here are some facts to help narrow down possible cause:
Carbs professionally overhauled by a highly respected forum member.
Compression numbers are ok, but not thrilling. 140, 160, 145, 140.
(I may check compression again with all plugs removed at the same time)
Paper air filter
Points gaps in spec
Valves adjusted to .004
Static timing test looks ok, but I may repeat and try tweeking to see if it changes anything
Harley take-off mufflers installed
New belts installed
I know that numerous members here have used similar take-off mufflers without having to re-jet, so I hope that they aren't the issue.
Is it possible to run like this if the belts were off by a tooth?
Any suggestions or advice will be greatly appreciated, especially from anyone who may have experienced and remedied a similar issue.
Thanks!
'78 GL Not Quite There Yet
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- tomk1960
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'78 GL Not Quite There Yet
1986 VFR750F Interceptor
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000
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Re: '78 GL Not Quite There Yet
If they are catalytic style mufflers, they may be too restrictive.
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- chewy999
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Re: '78 GL Not Quite There Yet
I'm in a similar position with my 1980 1100. I'm happy to ride it but when I open the throttle it just doesn't sound or feel like it should. My carbs were built by a respected member too, but the carbs still have to be set to the bike and some parts like jets may be worn. My compression test figures were all in the 160+ range, so I assume the valves and heads are ok. Points back to carbs imho.
Previous Rides,
1980 CB250N Good to learn on
1981 CX500 good mid range tourer, went to Austria on it!
1983 GL1100C Pride and joy, sold when I bought my 1st house, big mistake
1985 GL650 Silverwing another mistake, horrible bike
1986 CBX550 Good commuter
1989 Suzuki GS750 (1976) cheap and cheerful until a dog ran out in front of me on Xmas Eve, 1991
Current bikes
2010 CB1300 back on a bike after 19 years, two divorces, children grown up etc
1980 GL1100 NOW ON THE ROAD, still use CB1300.
1980 CB250N Good to learn on
1981 CX500 good mid range tourer, went to Austria on it!
1983 GL1100C Pride and joy, sold when I bought my 1st house, big mistake
1985 GL650 Silverwing another mistake, horrible bike
1986 CBX550 Good commuter
1989 Suzuki GS750 (1976) cheap and cheerful until a dog ran out in front of me on Xmas Eve, 1991
Current bikes
2010 CB1300 back on a bike after 19 years, two divorces, children grown up etc
1980 GL1100 NOW ON THE ROAD, still use CB1300.
- tomk1960
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Re: '78 GL Not Quite There Yet
Is it possible that even this style muffler could be catalytic?twowings wrote:If they are catalytic style mufflers, they may be too restrictive.
I'll find out what year/model HD these came off of and can then confirm. If that's the issue, the fix is easy.
1986 VFR750F Interceptor
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000
- OCR
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Re: '78 GL Not Quite There Yet
If they were catalytic style mufflers there will be a port for the connection back to the intake that needs to be plugged.
79 CX500custom
76LTD
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- Sugs
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Re: '78 GL Not Quite There Yet
If the cat is in the muffler you can take them off and look down the inlet. If you see honeycomb like material, that's the cat.
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'79 Honda GL1000 Goldwing
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- desertrefugee
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Re: '78 GL Not Quite There Yet
Those look a lot like my non-cat Sportster mufflers. A quick way to eliminate the exhaust restriction question would be to pop them off and go for a "loud" ride. You'd know pretty quickly if that's the problem.
If not, I'd look for stuff like choke linkage sticking and keeping the blades closed or partially closed.
...Or maybe the advancer plate is gummed up and not free to move.
It'd also be pretty easy to pop off the timing covers, roll the engine to TDC (T1 mark) and see how things line up.
<EDIT: Of course, the assumption here is that the carbs are right. Sticky slides would exhibit the symptoms you describe, too>
If not, I'd look for stuff like choke linkage sticking and keeping the blades closed or partially closed.
...Or maybe the advancer plate is gummed up and not free to move.
It'd also be pretty easy to pop off the timing covers, roll the engine to TDC (T1 mark) and see how things line up.
<EDIT: Of course, the assumption here is that the carbs are right. Sticky slides would exhibit the symptoms you describe, too>
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- gltriker
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Re: '78 GL Not Quite There Yet
H-D Softail slash-cut catalyst mufflersSugs wrote:If the cat is in the muffler you can take them off and look down the inlet. If you see honeycomb like material, that's the cat.
Cliff (74yrs )
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RE: a thorough fuel tank cleaning
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Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
Keep your eyes and ears open and you'll learn something new, everyday.
New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST
^^^^^^^click up here^^^^^
RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi
"Can't see the paint when your looking thru the handlebars..........." -Oldewing
"I'd rather Ride than Shine" -RAT Me Too!!
Cliff
'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM https://nakedgoldwingsclub.com/forum/page/Welcome
previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.
- tomk1960
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Re: '78 GL Not Quite There Yet
I found out that the newer HD mufflers have a steel plug pressed into the middle that creates a lot of restriction. Both of these mufflers had those plugs. On top of that, one of them is marked "catalytic" and had the honeycomb material on the header end. I was able to punch through that with a 1" iron pipe and knock out the both plugs.
I'm not sure if these can be considered equivalent mufflers in terms of flow, since there's still honeycomb material going in a few inches on one of them. (even though there's a 1" hole going through the center)
They're back on the bike, so I'll give it a short ride once the roads dry up. Riding without any mufflers is also a good idea if it still doesn't run right.
Thanks for the info and suggestions!
I'm not sure if these can be considered equivalent mufflers in terms of flow, since there's still honeycomb material going in a few inches on one of them. (even though there's a 1" hole going through the center)
They're back on the bike, so I'll give it a short ride once the roads dry up. Riding without any mufflers is also a good idea if it still doesn't run right.
Thanks for the info and suggestions!
1986 VFR750F Interceptor
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000
1983 Honda CB1100F Super Sport - Red 1123 Resto-Mod
1978 Honda GL1000