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TOPIC: Hard to start
#1025463
SKWEARpeg (User)
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Re:Hard to start 3 Months ago  
I saw your 900 rpms response.

Use the enricher to start the bike when it's cold, and leave it on long enough(at least half out), to where the bike will respond properly to the throttle. If it continues to die from time to time when it's warm on a hard decel coming to a stop, I'd be looking ffor a vacuum leak from a cracked Coasting Enricher cover or a possible air leak at the intake manifold to head flanges. It's not always easy to find a leak at the flanges. It never hurts to remove the manifold, surface the flange faces, and reinstall the manifold using either Hylomar, or Permatex's Permasheild on the flanges outside of the orings.
 
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Last Edit: 2017/11/21 19:59 By SKWEARpeg.
 
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#1025464
KondratkoJoe (User)
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Re:Hard to start 3 Months ago  
I'm not sure what or where the coasting enricher is or what it does. If there were air leaks on the manifold or exhaust flanges wouldn't the bike behave poorly all the time?
 
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#1025465
rginsbtx (User)
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Re:Hard to start 3 Months ago  
Mine seemed to run good.
But had major decel popping. Would run a little better with the enriched pulled out a bit.

Replaced coasting enriched cover and diaphragm earlier.
Pulled carb and rejetted.
But most important was following the advice given here.
Rejettng the carb helped performance, but the removal of the manifold and refacing the manifold surface was the most impotant thing I did.
I have no more decal popping.
And my bike runs GREAT.


My thoughts are that you have a manifold leak. I also have read, that the manifold will get hair line cracks in them.
 
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Last Edit: 2017/11/21 22:24 By rginsbtx.
 
2005 Road Star Silverado Midnight Star
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#1025470
davej (User)
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Re:Hard to start 3 Months ago  
KondratkoJoe wrote:
I'm not sure what or where the coasting enricher is or what it does. If there were air leaks on the manifold or exhaust flanges wouldn't the bike behave poorly all the time?

If you are looking into the throat of the carb the coasting enricher is the little white/maybe tanish cover on the left side of the carb. Remove the cover and you will find a spring and diaphragm, carefully remove it. Inspect the cover for cracks, also pull/inspect the diaphragm and plunger attached to it. Make sure the plunger moves freely in it's bore if it don't move freely they can sometime be a little difficult to remove without damaging. Clean it all good and make sure the passages inside are not blocked with crud and the plunger moves freely in the bore. If you find damaged parts replace them. Also pull the intake and resurface as others have said. I believe your issue will be resolved when done.
 
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#1025471
SKWEARpeg (User)
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Re:Hard to start 3 Months ago  
KondratkoJoe wrote:
I'm not sure what or where the coasting enricher is or what it does. If there were air leaks on the manifold or exhaust flanges wouldn't the bike behave poorly all the time?


Vacuum leaks related to the flange area on the manifold, generally manifest themselves during those times when the vacuum is at it's highest inside the manifold. This happens when the throttle is closed. When you close the throttle, the throttle plate in the back of the carb throat(it is behind the slide you see when you look in the carb throat) closes off the throat except for a small area. The vacuum goes up as the carb switches from the venturi back to simple vacuum from the motor, to supply fuel.
If the leak is bad enough, yes, it will affect the motors peformance all the the time. It would become unride-able.
Slight leaks can be a nightmare to find. People will often spend more time fiddling and looking, then they would just removing, surfacing the flanges, and replacing the manifold.

Roadies have a reputation for manifold leaks. I'd put it right at the top of things I'd do to a new to me Roadstar I had purchased, as far as getting the bike in good running condition. Especially, if I was chasing a gremlin. As mentioned pull the enricher slightly, the next time the bike seems to want to die on a hard decel. If the bike stays running, then you know the enricher is supplying the needed fuel to counter the extra air from the leak.
 
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#1025479
davej (User)
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Re:Hard to start 3 Months ago  
Gordon I have seen the coast enricher plungers stuck in the bore and it also causes issues like he is having on quick throttle release.Along with the things you have mentioned. Just something to look at while it is opened up
 
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Last Edit: 2017/11/22 07:10 By davej.
 
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