Backfires through intake and exhaust
Thread Starter
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Stage III
Joined: Sep 2017
Posts: 3
Likes: 1
From: MO
Backfires through intake and exhaust
Hi everybody. I have a 98 heritage springer that I bought 6 months ago. It's been hard to start since I bought it, backfiring through the air cleaner and out the tailpipe. It's now gotten to the point where it won't run and just backfires. I'm an auto mechanic and in my line of work it would be an ignition timing issue, but I know Harleys are a whole other world. I wonder if the ignition module, which is a crane fireball hi4e, is advancing the timing like it's at 2500 rpm all the time. I read about pushrods being out of adjustment and causing this issue, but I pulled the covers down, set the cam off the loved and I can rotate them with my fingers and they have no free play. Any ideas?
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,893
Likes: 8,001
From: poway
Probably has an intake manifold leak.. Spray some brake clean around the flanges that connect the manifold to the heads. See if idle changes. Check carb to manifold. Check to make sure the petcock vacuum line will hold a vacuum. Same with voes switch line. I would look for exhaust leaks..
Thread Starter
|
Stage III
Joined: Sep 2017
Posts: 3
Likes: 1
From: MO
Probably has an intake manifold leak.. Spray some brake clean around the flanges that connect the manifold to the heads. See if idle changes. Check carb to manifold. Check to make sure the petcock vacuum line will hold a vacuum. Same with voes switch line. I would look for exhaust leaks..
Cruiser
Joined: Jan 2016
Posts: 160
Likes: 14
From: North of Denver
same concepts apply...
air, spark, gas
verify pushrod/ lifter pre-load
verify compression & leak down
If it starts with choke and will come up to operating temp but then won't start/ run once the choke is closed...I'd suspect gas (carb primary), more than ignition timing.
air, spark, gas
verify pushrod/ lifter pre-load
verify compression & leak down
If it starts with choke and will come up to operating temp but then won't start/ run once the choke is closed...I'd suspect gas (carb primary), more than ignition timing.
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Road Warrior
Joined: May 2012
Posts: 1,423
Likes: 535
From: Oregon
Hi everybody. I have a 98 heritage springer that I bought 6 months ago. It's been hard to start since I bought it, backfiring through the air cleaner and out the tailpipe. It's now gotten to the point where it won't run and just backfires. I'm an auto mechanic and in my line of work it would be an ignition timing issue, but I know Harleys are a whole other world. I wonder if the ignition module, which is a crane fireball hi4e, is advancing the timing like it's at 2500 rpm all the time. I read about pushrods being out of adjustment and causing this issue, but I pulled the covers down, set the cam off the loved and I can rotate them with my fingers and they have no free play. Any ideas?
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Grand HDF Member
Joined: May 2014
Posts: 3,826
Likes: 1,170
From: florida
i might be that your carb needs to be diss-assembled and cleaned,,,,,the slow/pilot jet affects idle,,,if it's plugged or partially blocked,,it wont start and run correctly. take it apart and clean it like you would a car carb and blow the passages with compressed air. then try it out with nice plugs.
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