Low Compression Problem.

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Re: Low Compression Problem.


Post by NightShift »

Dear Bill,
I think Indianut nailed it. My genuine Sifton 440 was a mild lift but you still couldnt kick it fast enough to read decent compression. Damn fine cams they were too!


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Re: Low Compression Problem.


Post by james »

An air cooled engine with low compression I would start by checking for tighter than normal push rods then go from there.


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Re: Low Compression Problem.


Post by cole »

That was my first thought also, what cam, glad ya got her figured. cole

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Re: Low Compression Problem.


Post by Hauula Pan »

I see you've gotten a lot of answers but here is some info. on the compression issue. My 52 pan is .060 over with low compression pistons & an Andrews #1 cam designed to run with the low compression pistons. My cylinders only have 50-54lbs. of compression and it starts & runs fine. So while yours may be worn it has plenty of compression to start & run. With anything other than the stock Linkert mine is tempermental and with the S&S super E it will start cold but is a real pain to start warm. With the S&S try giving it a couple squirts with the accelerator pump and kick it 3 or 4 times with ign. off to prime the cyl. retard the timing turn the ign. on and see if it fires or at least pops for you. I'm still running 6 volts and need a fully charged battery or its no go, so make sure you have good battery power. These pans are notorious for intake leaks so make sure you don't have a problem there. Make sure the timing is set dead on & pushrods are right etc. If everything is adjusted correctly and you have gas & spark it should fire with the amount of compression you have. I'm not saying it isn't worn, but you have enough compression so the problem is probably an intake leak or timing issue. What do the plugs look like? The S&S is too rich for most stock pans & you have to turn the mixture screw pretty much all the way in. Mine is barely cracked from full closed. Will it pop with a shot of starting fluid? If you can get it to pop or spit at all then it should go once everything is dialed in, but it all has to be right on, especially with the S&S. Best of luck.

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Re: Low Compression Problem.


Post by btperkins »

Thanks again for all your input! Your help and my skills (And That's Not Much Skill, Yet) had me try and look at a number of things suggested here. 38 years ago is coming back slow but sure. I worked on this until last Thursday and I then called a local Custom Cycle shop that specializes in old Harley's. The very first thing the owner asked was if I did a compression test? I did and I gave him the information. He asked if I could get the bike to his shop? I got a U Haul and my brother and I took it in. These professionals could not start this bike nor could they fathom the compression test they took. About 40 psi. on each cylinder! The owner remarked that there was something serious wrong. I told him the seller of this machine indicated the engine was rebuilt 1100 miles ago. The owner said so many people work on these old machines that think they know what they are doing and that thinking is what brings these old bikes to me. I told him this was an E-Bay purchase and he said, "Don't feel bad, you are not the first nor will you be the last" He then said, I'll bet you received no service documents and I'd bet again that the sellers name is not the registered name on the title! Right in both cases! The seller is being held accountable. I don't want to get my money back! I want this machine and the seller understands that he will be accountable for all repairs. And yes, the Harley Davidson dealer in Munster, Indiana told me and this is a Quote. I have no service mechanics that have any knowledge of a 1957 Panhead and how to perform or even verify a compression test. Ain't that something! So, I'll see what's what and I'll keep you informed1 Thanks again!


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Re: Low Compression Problem.


Post by Hauula Pan »

You can forget going to or asking just about any Harley dealership for anything on a Pan-head or even a Shovel-head for that matter. All you'll get is, "That's obsolete." They don't want anything to do with anything that old. They are only interested in servicing the new stuff they're selling. And from what I've seen they're plenty busy fixing that new stuff. So many guys around here have 2005's and newer that are always in the shop for some problem. Find a good independent shop that specializes in the old bikes and knows what they're doing and stick with them. Once its running just get a copy of an original service manual & Palmer's book and with those & the guys on this site you should be able to keep your bike going yourself. Glad to hear you found a reliable shop & that the seller is stepping up to the plate for the repairs. Best of luck & post some pictures of the old beast.

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Re: Low Compression Problem.


Post by Norseman68 »

Hey right on I was stationed in Michigan City Indiana for 6 years in the u.s. Coast Guard at Washington Park Marina I used to ride with a lot of guys from Valparaiso LaPorte I believe there used to be an old Harley shop in Laporte mypinelake called Darst Harley-Davidson.
Unfortunately it was just a shell of a building when I was there from 98 to 03 but I got to meet mrs. Darcy she lives at an old folks home in LaPorte when I went and talked to her and she showed me some old photos of the place when her and Hap owned it.

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