low cold cranking

[-JC-1]

yesterday I put the compression gauge on my 124, and got 120 both holes, with the electric compression releases unplugged, and 90 with them plugged in.
This motor was at 200, with 11.2 comp with S&S 640 gear drive cams,
I pulled the cam chest apart to see if I screwed up on the cam install, but both inner and outer gears are indexed properly to each other, and I've got the inner front gear on the front cam, and the inner rear gear on the rear cam, so thats good-
I was convinced last night after I did the ccc test that i had screwed up the install someway, but so far I haven't found my mistake-
I'm wondering what my next step should be?
appreciate any suggestions
joe

[xzo124]

You sure you had the throttle WFO  ??...xzo

[06roadglide]

Make sure your battery has a good charge on it.  I usually put a charger on as I crank.  Are your lifters pumped up yet?  Pushrods adjusted properly.  Air filter off? 

[-JC-1]

yes it was wide open, and I thought maybe the guage was bad, so I put it on my softail and it got 210, right where it should be 

[Jeffd]

air cleaner off?  seems strange they would both be identical and low.  What symptoms did you have that made you check in the first place?  maybe the EAC's are not closing all the way.  I would warm it up good and then check again.

[-JC-1]

air cleaner was on, I forgot to take it off- no symptoms really, just double checking-
how much difference would the air cleaner on make?
I'm kind of wondering about the compression releases myself- it has been starting easier than it should- I thought it was because I switched to the mikuni, but maybe carbon build up in the release?

[Admiral Akbar]

Coupla squirts of oil in the cylinders and try again,, See whet you get..

Also try taking her out and run it up to the red line a couple times and check again warm..

Max

[BUBBIE]

-JC-1

How long has this Build been running (miles?) When did you first notice it was Starting EASY?


signed....BUBBIE

[rbabos]

Time for a leakdown test to find out the source.
Ron

[Barrett]

It seems like you would have noticed a loss of power with that big of a drop.

[Jeffd]

if there are no symptoms and it runs good be happy.

[-JC-1]

I've got 9,000 miles on this latest [and hopefully last] build on this motor
I noticed it starting easier after I swapped out the xxx carb for the mikuni- that was a couple of weeks ago
I haven't noticed a drop in power-
I'm thinking about re-installing the camplate and cams and checking it again, and maybe borrowing a leak down tester-
it doesn't use any oil, and the plugs look good, white with a fuel ring deep, and about 4 turns of color on the threads-

based on past experiences my default position is that I screwed something up- I'm a carpenter not a mech, but I'm trying to learn 
thanks to all

[BUBBIE]

I'm trying to follow you here.. You say 9000 miles on the build. If your compression WAS HIGHER like you stated 200 lbs. and you Only took off the carb and added the mikuni.
That Would NOT have anything to do with lower compression.... When  was the Last cc pressure taken? At 200#s...
IF you fiddled with the cams AFTER the 200 # reading, It may be what you say, a Screw-up,, BUT you say you took it apart to check and everything was fine...
Your LACK of compression is EVEN and I would SUSPECT the relief valves as BOTH cylds. are OFF  the same OR the cam timing is OFF on the Crank to Cam Marks NOT on the Cam to Cam. THIS IS possible.

If it was recient or even Long ago, I doubt 9000 mile would Have anything to do with the Drop in pressure.. Saying earlier you had it and now you don't and BOTH cyls even? I don't suspect head gasket as both are same

So check and get back with a Report.. Hopefully GOOD .

signed....BUBBIE

[rbabos]

I'd like to add that I'm surprised it will start and stay running at 90 psi. Sure that gauge is accurate? Have you tried it since testing it on the softail?
Ron

[BUBBIE]

rbabos,

He said that it was 120 and 90 with the reliefs on.. Still a LONG Way from 200lbs..

signed....BUBBIE

[rbabos]

rbabos,

He said that it was 120 and 90 with the reliefs on.. Still a LONG Way from 200lbs..

signed....BUBBIE

So, it's starting at 90 psi, right?
Ron

[BUBBIE]

YES,  rbabos,,,,, you are right.. My BAD.. 90# like you said....

signed....BUBBIE

[Hillside Motorcycle]

Sure the releases were inoperable, at the time of the check??
Scott

[ORork]

You say you noticed this symptom after installing the Mikuni. I would do as Max says and instill some oil through the spark plug holes and check the pressure again. If you find the pressure is back up to snuff, I would think the Mikuni is rich to the point of washing the oil from the rings and ring grooves. Get an accurate reading of the A/F ratio.

[-JC-1]

I hope to get it back together this evening, I've got the Mikuni jetted at 25 pilot, 2 turns out , 97 needle clipped in the middle, 185 main, and my afr guage shows a little rich on the front cylinder- the only one being read, and my plugs look good-
I don't know about the releases, it seems to me that if I get a 30 psi difference between them being plugged in and unplugged they are working?
in order to get them off, I'll have to pull the rockers,
after reading all of your responses, I think the readings I got have to be inaccurate- or operator error-
I'm going to try and get it back together this pm, and I'll test it again, If my results are the same, I'll try the oil in the spark plug hole and retest,
then I could pull the releases, which i don't want to do unless all else fails-
I don't mind pulling the cams and re-installing, it's been good practice learning how, but jeez!

thanks again, I appreciate the help!

joe

[-JC-1]

I had plugged in the battery tender yesterday am, and then last evening I reinstalled everything and it fired right up, so I checked the front cylinder and got 150 with the releases unplugged, and 120 plugged in-
the battery tender showed red, so I waited til the charger brought the battery to green, and just now  checked the rear, and got 120 both plugged and unplugged.
had the air cleaner off this time, and i made sure the throttle slide was wfo
Two things I know for sure: I need a new battery,and having the air cleaner off makes a difference
Beyond that, I trust these latest readings more than the first ones-
I'm thinking my next plan is to pull the rockers so I can get to the releases, and take them out and inspect them-

right course?

[1FSTRK]

You may want to try a leak down test first. You will be able to hear where the air is escaping before you go after the releases.

[86fxwg]

You may want to try a leak down test first. You will be able to hear where the air is escaping before you go after the releases.

K.I.S.S.

[-JC-1]

my goal this weekend is to find a leakdown tester

thanks-

[rbabos]

my goal this weekend is to find a leakdown tester

thanks-

I'm suspecting the releases themselves as in not sealing on cranking rpms. Extra pressure when running might close them. That, or there is an exposed hole in the threads that the releases thread into, caused from not going deep enough in the machining operation.
Leakdown test will show the problem, whatever it is.
Ron

[aharp]

Wouldnt be the first time S&S releases had an issue

[Jeffd]

I am missing something. NO symptoms, runs good other then easy starting?  Is not that we all want.

[hrdtail78]

Does it have easy starts in it?

[-JC-1]

ok- I picked up a Harbor Freight leakdown tester and this morning I brought the bike up to operating temp, and both front and rear showed at least 10% loss, and the only place I could hear air was over the releases, in the middle of the rockers, and there is alot of air-
cams are not easy starts

[rbabos]

ok- I picked up a Harbor Freight leakdown tester and this morning I brought the bike up to operating temp, and both front and rear showed at least 10% loss, and the only place I could hear air was over the releases, in the middle of the rockers, and there is alot of air-
cams are not easy starts

Look for thread depth and sealing of the releases. Also a visible hole to the threads of the release between the first and second fin. Might not be machined deep enough.
Ron

[hrdtail78]

What ever came of this?

[-JC-1]

I pulled off the rockers to get to the heads and releases, took them out, and contacted S&S tech support-
Turns out the electric releases are not serviceable items.
I'm going to plug the release holes and do another leakdown test.
These releases are a pain to get to compared to the standard ones.
Thats all I've had a chance to do so far, I'm also going to test the electric releases on my bench now that I have them out, to see how they behave.
The releases look fine externally, no excessive carbon build up, and I can operate the plunger manually ok.

[rbabos]

I pulled off the rockers to get to the heads and releases, took them out, and contacted S&S tech support-
Turns out the electric releases are not serviceable items.
I'm going to plug the release holes and do another leakdown test.
These releases are a pain to get to compared to the standard ones.
Thats all I've had a chance to do so far, I'm also going to test the electric releases on my bench now that I have them out, to see how they behave.
The releases look fine externally, no excessive carbon build up, and I can operate the plunger manually ok.

Are they leaking at the threads, as in not machined deep enough to seal past the first fin of the head?
Ron

[-JC-1]

I pulled off the rockers to get to the heads and releases, took them out, and contacted S&S tech support-
Turns out the electric releases are not serviceable items.
I'm going to plug the release holes and do another leakdown test.
These releases are a pain to get to compared to the standard ones.
Thats all I've had a chance to do so far, I'm also going to test the electric releases on my bench now that I have them out, to see how they behave.
The releases look fine externally, no excessive carbon build up, and I can operate the plunger manually ok.

Are they leaking at the threads, as in not machined deep enough to seal past the first fin of the head?
Ron

I don't think so-as long as they are installed all the way, and they were, I'm not sure if they could leak past the threads?





I did put power to the releases on my bench, and they do open and close like they should.

I have to give credit to Chris at S&S Tech Support, he has been very helpful to me through emails and phone calls.

[rbabos]

-JC-1: Check your pm.
Ron

[Admiral Akbar]

So this was after you ran it up to the limiter a couple times?

Max

[hrdtail78]

Do those heads bleed pressure out or into the exhaust port?

[-JC-1]

So this was after you ran it up to the limiter a couple times?

Max

Not sure I understand? Got my limiter set at 6200, I don't live there, but it's not foreign territory either-

Do those heads bleed pressure out or into the exhaust port?

They bleed pressure through the release- that's what S&S tech told me yesterday-

[Admiral Akbar]

The idea is to make sure the valves are clear of carbon build up..

Not familiar with how SnS releases bleed off pressure as to where the exhaust is  but if it's out the top, looks like you found one problem..

Max

[-JC-1]

Yes they bleed out the top, through the solenoid body, S&S had a cutaway version of the release and that's the way it was explained to me, as I could not see any apparent release hole.

joe

[Deye76]

I know of 2 with 124" ers that plugged that hole and installed manual releases. No more problems.

[-JC-1]

I know of 2 with 124" ers that plugged that hole and installed manual releases. No more problems.

I've been thinking about that too, as long as I'm this far into it, I could pull the heads and send them out to be tapped for conventional releases-
there's less room on these heads because of the equal length head bolts, I assume there would still be room?



[attachment removed after 60 days by system]

[FSG]

Yes they bleed out the top, through the solenoid body, S&S had a cutaway version of the release and that's the way it was explained to me, as I could not see any apparent release hole.

Could be true but I doubt it.

#1 is a crush washer/seal, if deformed it'll leak, just like a spark plug.  Perhaps replace them and try the leakdown again
#2 looks like a hole and as that area looks to be covered with carbon I'd say it's the CR exit into an exhaust passage in the head.



#? the pic is dark in that area can you get a better pic?

[rbabos]

FSG: I just put the pics into a photo editor and increase the gamma.
Ron

[-JC-1]

I put a new crush washer on- they are the same as a sparkplug- and did a leakdown on both cylinders with the same release,
I got 10% on both
The only place I could hear air was on top, but I could not pin down a more precise location.
Not through the carb or the pipe.

Ron, I did look all through the fins and see no carbon trace

FSG, I think I'll pull the pipes and see if I can find evidence of an exhaust passage

Thanks alot guys,

joe

[Admiral Akbar]

FSG good eyes... Got me wondering HTF the sucker works,, Is there a passage in the going to say the exhaust port?

Max

[FSG]

Must be, we need JC to pull the exhaust and take a pic looking into the port with a flashlitght above the CR hole. 

[FSG]

S&S Heads with CR's

[Admiral Akbar]

Unless there is a step at the end of the compression release hole that the end of the release seats against, what keeps compression from leaking past the threads?

Max

[FSG]

...what keeps compression from leaking past the threads?

I don't know, but the end of the CR sure looks like it's been inside or against something and has been sort of polished as it's been unscrewed.

[FSG]

another => http://www.rbracing-rsr.com/CompressRel.html

[Deye76]

I think S&S came out with Easy Start cams a/c better to give up on those problematic electric releases and find another discrete solution. 
BTW there's room for manual releases in S&S heads, the Evo ones anyway. Not sure why the TC wouldn't accomodate them.

[-JC-1]

FSG-
You are correct sir, there is a shoulder at the bottom of the hole.
I did not consider that until you mentioned it, so there must be a passage from the release hole to the exhaust port- I will investigate further!
I have a pair of S&S release plugs on order, I considered today threading a bolt of the proper size into the hole in order to check leakdown independent of the releases, but I'm glad I didn't now, not knowing how thick the material is at the bottom of the hole, with my luck, I would have pushed it into the cylinder!
many thanks to all 

[attachment removed after 60 days by system]

[ReddHogg]

i was just reading back thorough this and thought maby check valve lash

[R.Bingham]

I was just reading the link FSG provided for RSR Racing and something caught my eye.

S&S Cycle developed an Electric Compression Release Kit that solves all of these problems. Oh, you still have to have your battery well maintained and it's a good idea to have the headlight "off" during the cranking phase as well as leaving the throttle plate closed to stack things in your favor. The electric releases are tied to your starter and won't close until you release the starter button i.e. when the engine starts. They also do not invade the combustion chamber with a large tapped hole, nor do they vent externally...they vent through a cross-drilled passage into your exhaust port.

So if I'm reading this correctly,since the releases are tied to the starter and won't close until the starter button is released, wouldn't this cause a low/ false reading for a cranking compression test?
it also says that they vent through the exhaust port.

[FSG]

So if I'm reading this correctly,since the releases are tied to the starter and won't close until the starter button is released, wouldn't this cause a false reading for a cranking compression test?

Yes.  So back to the OP yesterday I put the compression gauge on my 124, and got 120 both holes, with the electric compression releases unplugged, and 90 with them plugged in..  I guess that is normal, the CR's are doing their job.

[rbabos]

Just looking at the pics and seeing two places need to seal at the same time. Good luck with that. Piss poor setup if you ask me. Appears to be leakage at both sealing points in the head from what I can see.
Ron

[-JC-1]

Just looking at the pics and seeing two places need to seal at the same time. Good luck with that. Piss poor setup if you ask me. Appears to be leakage at both sealing points in the head from what I can see.
Ron

That's what I think too, the hole and the release have to match perfectly.

I do know that the compression releases are opening and closing, but to be working properly they must maintain a seal, which is an entirely different matter.

I think I'm going to redo the leakdown and try to pinpoint the air loss with a mechanics stethoscope.

[R.Bingham]

So if I'm reading this correctly,since the releases are tied to the starter and won't close until the starter button is released, wouldn't this cause a false reading for a cranking compression test?

Yes.  So back to the OP yesterday I put the compression gauge on my 124, and got 120 both holes, with the electric compression releases unplugged, and 90 with them plugged in..  I guess that is normal, the CR's are doing their job.

Oops, I overlooked that.

[86fxwg]

try to pinpoint the air loss with a mechanics stethoscope.

  Use the rubber hose from the mechanics stethoscope or Spray the suspected area with tire leakfinder or soapy water from a spray bottle. If you have any buddys in the auto repair buissness borrow a smoke machine.
Dave