Bought my first harley from an out of state. It is an 09 heritage softail. Had a miss at low end. Like when you first roll on the throttle. Other than that it seems to run fine. Took it to local dealer for a Dyno tune. Dealer says specs are all over the charts. He found a bad throttle body seal but that did not fix. This bike has a screamin eagle stage4 103 race kit in it. The dealer says he thinks the heads and intake are too big for a 103 motor(58mm throttlebody and 2 1/8" valves). He feels we need to change out the heads and intake. This could cost $2,500. He did point out that the dealer that did this build used stock head gaskets instead of screamin eagle head gaskets which are alot thinner. Could the thickness of the head gaskets be the cause of my problems? Looks like what seemed a good deal is going to turn into a money pit.
Motor problems
- Thread starter jlbeebe
- Start date
Hoople
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I would say that is Not the cause of the low end "miss". Lots and Lots of things come to mind before needing thinner head gaskets and different size valves. .
You need to know what ingredients went into building your engine. Not just the word "kit" but all the exact part numbers of what is inside. I would not be tearing into the engine without 1st making sure the mapping is correct for the parts installed. That "miss" could VERY easily just be a change in a few map cell values.
It sounds like you will not be doing any of the work yourself. Is that true?
No I will not be doing any of the work. The kit comes out of the harley davidson screamin eagle catalog. I gave the dealer the origanal ticket for the work that was done. This was done by treasure coast harley in Florida. I have the bike at my local dealer(Big barn harley in DesMoines Ia). They have had it on the dyno several times and are not having any luck with it.
Dealer said that stage 4 race kits are not covered under factory warrantee
My biggest worry(besides spending alot of money I don't need to) is that if I tell them to go ahead and they replace this stuff and it doesn't fix the problem I have just spent 2500 plus the bill I have already for the work they have done so far.
My biggest worry(besides spending alot of money I don't need to) is that if I tell them to go ahead and they replace this stuff and it doesn't fix the problem I have just spent 2500 plus the bill I have already for the work they have done so far.
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Hoople
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An inertia dyno won't help you much on a problem like yours. Don't let the word "Dyno" fool you into believing that is the final word. Your problem is an "off Idle" bog or miss. Inertia dyno's are only useful for wide open throttle testing. An inertia dyno is going to be of little help for what your trying to correct.
I wonder if they even tried the simple things like changing the acceleration enrichment factor in the mapping. That 1 simple adjustment/change could fix a problem like yours. Did they perform a simple compression test to see what your foundation is?
I hate to say it, but I would not let that dealership take my engine apart unless they told me everything they tried before hand.
I wonder if they even tried the simple things like changing the acceleration enrichment factor in the mapping. That 1 simple adjustment/change could fix a problem like yours. Did they perform a simple compression test to see what your foundation is?
I hate to say it, but I would not let that dealership take my engine apart unless they told me everything they tried before hand.
Hoople
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One more thing to add. You really find out how much cam you really have in this engine. Having "too much cam" will effect everyday street-ability of the engine. Radical cams have late intake valve closing and a bunch of overlap which leads to low intake vacuum. That is normal but it also makes the engine not as "streetable" as it was when stock.
I don't know what a Stage 4 packs for cams, but it is something that can be overdone in a hurry.
I don't know what a Stage 4 packs for cams, but it is something that can be overdone in a hurry.
gs34
Junior Member
I think Hoople is giving you excellent advice. And as for the head gaskets...the thickness will have a lot of bearing on the compression ratio. The thnner the gasket, the higher it will be. Possibly the thicker gaskets were used specificly to keep the ratio down in a more "streetable" range.