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Cranking issues (lifter related?)

Started by Burnout, February 13, 2020, 11:14:44 AM

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Burnout

February 13, 2020, 11:14:44 AM Last Edit: February 13, 2020, 02:32:07 PM by Burnout
To preface, 110" RevTech (to my knowledge untouched and low miles)
Battery load tests good 3 times in a row without charging
New "All-Balls" starter (with a dyno sheet) and one piece starter jackshaft.
Welding cable battery leads

Starter stalls on first cylinder that comes up predictably, then cranks normal.
I feel it is not a spark issue as it will do it after it has sat for many days and has no fuel in the motor.

I'm thinking lifters are bleeding down causing the intake to close early and compression pressures skyrocket?
I have no data on these motors and they are out of production.
I'm hesitant to bust out the parts cannon, as it already has an abundance of new parts that have not solved the issue.

What cam was used in these motors? (Short duration?)
Did they use lifters with travel limiters in them?
Is there any history with these motors in this area? (I have not had this problem with other big motors)

Should I attempt a "bottom up" adjustment instead of a "top down"?
Or will the lifters pump up and cause a "bad thing" to happen?
Or can I disassemble the lifters and put limiters in, to keep the lifter in it's "top down" working position?

Any thoughts? Bigger cam? Install a kicker? Sell the wannbe drag motor on eBay and install S&S?
Is this a "thing"? Or am I smoking too much high grade?

They don't call me Ironhead Rick just because I'm "hard headed"

wfolarry

My bike was doing that for years until I changed ignition systems. The new one lets the motor turn over before ignition.
Back when they had kick starters kick back would be felt in your knee.  :cry:
If it cranks fine after it gets over that first hump there's no major problem. A little fine tuning. Travel limiters help. The battery in my bike is small [same size that was in my FXE Shovel] & without releases & travel limiters forget about starting it on a cold day.

Burnout

I have not completely eliminated spark but it can't have any fuel in it to fire after sitting for days. Stone cold. It takes 3 or 4 squirts and the choke on for it to fire, so I'm certain it is not a spark issue. I'll disable the spark tomorrow to be certain.

Sure would like to hear from someone who has dealt with this issue.
My 93" Shovel with the craptastic Hitachi starter cranks better than this thing!

They don't call me Ironhead Rick just because I'm "hard headed"

kd

In your OP you don't say whether or not you get a couple of lifter clacks or more when it starts after this hard cranking or if it happens every start-up or not..
KD

Dan89flstc

What is size are the ring/pinion gears?
US Navy Veteran
A&P Mechanic

Burnout

Quote from: kd on February 14, 2020, 06:02:15 AM
In your OP you don't say whether or not you get a couple of lifter clacks or more when it starts after this hard cranking or if it happens every start-up or not..

No noticeable lifter noise. but it doesn't fire right away. I think it spins enough that the lifters refill before it fires.
They don't call me Ironhead Rick just because I'm "hard headed"

Burnout

February 14, 2020, 08:25:46 AM #6 Last Edit: February 14, 2020, 12:40:09 PM by Burnout
Quote from: Dan89flstc on February 14, 2020, 07:55:44 AM
What is size are the ring/pinion gears?

It has a 3" BDL belt drive that has a coarse tooth ring gear. I think it is a 9 tooth pinion, I'll verify today.

EDIT:

I disabled sparks this AM and problem is reliably repeatable.

And BDL F-5 3" belt drive has the coarse teeth I counted a 9 tooth pinion.


I did notice that it did not get better after cranking, which blows my theory out of the water.
After cranking a few revs the lifters should be filled and cam timing restored.

I failed to check cranking compression because I assumed a production motor would have a reasonable setup.
WRONG! This assumption has bit me squarely on the ass.

Yep, 200# cranking compression is just stupid! I'm surprised it doesn't ping.
Thanks for the replies.

They don't call me Ironhead Rick just because I'm "hard headed"

kd

 :up:  Nice find though.  It kind of brings back the KISS theory - Check the compression first because it's easy and non invasive. :wink:
KD

Burnout

February 14, 2020, 08:54:26 PM #8 Last Edit: February 14, 2020, 09:30:03 PM by Burnout
Looks like that motor comes with a EV72 cam which should close the intake late enough.  :scratch:

Maybe an adjustable gear got installed advanced by mistake?

I seem to recall there is another tool made besides Jims for re-positioning a cam gear, but the googles are not helping or I'm tired.
They don't call me Ironhead Rick just because I'm "hard headed"

RTMike

I just finished one in January with the same issue,it has a Andrews EV72 cam in it it was advance 3 degrees I chandged that to the stock specks,put a DTT ignition in it,manual compression releases and tapped the heads for external breathers as this engine has no rotary breather it controls crank case pressure the same as a Twin Cam I also replaced the pushrods with adjustable units just to be safe.It works better but without the compression releases you would be back to square one when it's hot.
It runs and idles like it should now,but still a bear to crank over.
I found gasket sets on the internet the only place Available,and to note they use a fire ring for head to cylinder seal ,no head gaskets.with all the parts and BS I went threw the compression releases and external breathers work the rest is questionable,the bike runs great now but expensive.

Burnout

So it is a keyed gear?

Surprised they didn't use adjustable pushrods....
They don't call me Ironhead Rick just because I'm "hard headed"

RTMike

No same as a evo or Shovelhead press fit

Burnout

Thanks

I wonder if the head gaskets are the same as what Sputhe uses?
They don't call me Ironhead Rick just because I'm "hard headed"

RTMike

No head gaskets sompression fit on the head and cylinder,just like TF heads