I own a 1974 GT250, totally original, unmolested, 21000 mi. bike that has developed a weak right side exhaust pulse and note. A couple
weeks ago it became harder to start and turned out to be a bad set of points. I cleaned them and all good but noticed a slight sputter on right
side exhaust. Compression is 120# each side, baffles cleaned, and does run very good. And I did check exhaust temp at head and right side about
60-70* cooler.
Ideas?
Thanks.................Hank.
GT250 One Sided Weak Exhaust Pulse
Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan
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- Still in the Driveway
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- Yeah Man, the Interstate
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Re: GT250 One Sided Weak Exhaust Pulse
How did you clean points? Many will tell you not to file them, it will remove coating. That being said I have cleaned points with a file without issue.
Does the point arm move freely? If the grease in the pivot dries, the movement becomes restrictive and will cause issues.
Is there sparking in the points while running? This could be caused by condenser breaking down.
Does the point arm move freely? If the grease in the pivot dries, the movement becomes restrictive and will cause issues.
Is there sparking in the points while running? This could be caused by condenser breaking down.
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Re: GT250 One Sided Weak Exhaust Pulse
Check the quality of the spark.. I had a lot of starting and mis-fire issues until I replaced the old original coils. old coils will measure ohms ok but spark may be weak.
- jabcb
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Re: GT250 One Sided Weak Exhaust Pulse
Start with a good fully-charged battery. These twins have a tendency to run on one cylinder with a flat battery.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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Re: GT250 One Sided Weak Exhaust Pulse
Thanks for replies.
I did file points then polished w/320 then 600 paper. Cleaned old grease off cam and finely lubed with syn grease. Point arms seem to normally sprung to me. I keep battery on a tricycle charger and is good.
I plan to R & R points/condenser this week, trying to locate a quality set. Spark looked good from plug to ground but not a hot blue.
Maybe coil? Runs so damn good though!! Maybe I don't know what good is...........
Hank
I did file points then polished w/320 then 600 paper. Cleaned old grease off cam and finely lubed with syn grease. Point arms seem to normally sprung to me. I keep battery on a tricycle charger and is good.
I plan to R & R points/condenser this week, trying to locate a quality set. Spark looked good from plug to ground but not a hot blue.
Maybe coil? Runs so damn good though!! Maybe I don't know what good is...........
Hank
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Re: GT250 One Sided Weak Exhaust Pulse
After receiving new points/condensers from the UK it appeared the wires need to be spliced. There are no connectors on new parts or from what I can see on bike. Kind of deterred me a bit as not anxious to cut harness on this original antique. Are there small bullet connectors wrapped under the tape or will I need to add them? Time for me to get busy while the weather is still ugly.
- jabcb
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Re: GT250 One Sided Weak Exhaust Pulse
A pic of what you have would be helpful.
We can’t post pics here. Post pics on an image sharing website. I use Flickr, which is free & easy to use.
Then include links to those pics here.
We can’t post pics here. Post pics on an image sharing website. I use Flickr, which is free & easy to use.
Then include links to those pics here.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
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- Expert racer
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Re: GT250 One Sided Weak Exhaust Pulse
Wires should not need to be spliced, the factory wiring to the points should have a little fork which connects to the points terminal, and the condensers should have a little pigtail with a similar small fork for connecting to the points.
1976 GT380 - wounded by me, and sold on
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2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
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- jabcb
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Re: GT250 One Sided Weak Exhaust Pulse
The GT triples have an improved design making it easier to change the condenser.
Take a look at this eBay listing for a GT250 alternator to see the GT250 setup:
https://www.ebay.com/itm/403103593452
It’s been a while. The GT250 condenser comes with the wires attached. The wire with little fork connects to the points. Suzuki used a butt connector for the other wire that connects to the coils. Don’t remember if the butt connector was a crimp or soldered connector. A PITA design.
It’s been my experience that the butt connector is often dodgy because a prior condenser replacement was done poorly.
Do not twist the wires together an expect the bike to run correctly.
Take a look at this eBay listing for a GT250 alternator to see the GT250 setup:
https://www.ebay.com/itm/403103593452
It’s been a while. The GT250 condenser comes with the wires attached. The wire with little fork connects to the points. Suzuki used a butt connector for the other wire that connects to the coils. Don’t remember if the butt connector was a crimp or soldered connector. A PITA design.
It’s been my experience that the butt connector is often dodgy because a prior condenser replacement was done poorly.
Do not twist the wires together an expect the bike to run correctly.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE