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TOPIC: Re:Firing on one cylinder
#1020757
Paladin (User)
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Re:Firing on one cylinder 6 Months ago  
Explains it well enough. I couldn't figure out the throttle part, but the decomp solenoid makes perfect sense. It'll be Saturday before I can get back to working on it again so I'll let everyone know what I find out (I'll probably need help interpreting the leakdown reading anyway.) At least now I know that I should be looking for 170-175psi for compression though. From what everyone has been saying though, if the readings are bad I'm thinking it's: skip the lifters and get a new motor time though. (What with having to replace cams and lifters being bad enough, if anything else had to be done, replacing the motor would be cheaper) Thanks again!
 
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#1020760
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Re:Firing on one cylinder 6 Months ago  
Probably better to start with the piston at the bottom on the front cylinder leak down test. The TDC position is for when the lifters and pushrods are still installed. With the piston at the bottom you don't have to worry about holding the engine from rotating when air is applied. The piston can be forced down with a lot of force.
 
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#1020762
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Re:Firing on one cylinder 6 Months ago  
texasscott1 wrote:
Probably better to start with the piston at the bottom on the front cylinder leak down test. The TDC position is for when the lifters and pushrods are still installed. With the piston at the bottom you don't have to worry about holding the engine from rotating when air is applied. The piston can be forced down with a lot of force.

sounds like a plan - makes sense. Thanks!
 
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#1020767
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Re:Firing on one cylinder 6 Months ago  
Just scoping the cylinders walls would probably reveal plenty.
 
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#1020781
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Re:Firing on one cylinder 6 Months ago  
BikerRon wrote:
Just scoping the cylinders walls would probably reveal plenty.

Good idea and that's one tool I do have on hand!
 
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#1020792
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Re:Firing on one cylinder 5 Months, 4 Weeks ago  
I think you guys are getting way ahead of yourselves with all this leak down and compression test crap. All the time you have spent talking about it you could have had the cover off the side and checked the cam to see that, that is your problem. Don't syke yourself out. Check the freakin cam already. I don't know why sometimes you guys make more of an issue than what it is. These bikes rarely have 1 major issue let alone 2 at the same time. It appears that the bike was running just fine before this happened and if the rings were bad it wouldn't have you would have had some sort of an indication of that. Also if the rings were bad it wouldn't make a cam go bad.
 
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#1020797
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Re:Firing on one cylinder 5 Months, 4 Weeks ago  
I think the Compression test/Leakdown test got started where I had mentioned doing a compression test and the results being 110psi on the rear cylinder and 60 psi on the front cylinder. However, I apparently did the test wrong and people were suggesting I re-try it with the decomp solenoid removed and the throttle wide open so I could get more accurate results. Also, in spite of the fact that I change my oil regularly using Amsoil and even changed it as recently as 1000 miles ago, when I pulled my valve cover and spacer off the interior was full of sludge and black oil. The pushrods were coated with that too. So there was some concern over carbon getting by the rings and into the oil where it could cause premature wear and tear on the cams/lifters.

Over the years, while my Roadie has been pretty good to me, I have had problems. Electrical problems mainly though with the starter and starting. I've gone through 6 batteries in 7 years (keeping them on a high quality Tender whenever I'm not riding) - all of them high quality batteries, along with 3 starters, two starter solenoids, and miscellaneous other problems connected with starting. But that's a different issue that I haven't been discussing in this thread. I'm just trying to learn everything I can and I appreciate everyone's suggestions and help. I understand what you're saying, but now is as good a time as any to be checking out all this stuff. If the motor has compression problems on top of the cam/lifter problems, then it might be cheaper to just replace the motor - although I could be getting someone else's problems that way too....
 
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#1020798
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Re:Firing on one cylinder 5 Months, 4 Weeks ago  
Well, with the mention of a recall being done and one member suggested a tech might have inadvertently honed the cylinders, a scope should reveal fresh cross hatches in the ceramic coated walls.

you could have had the cover off the side and checked the cam to see that, that is your problem.

Dave,

If he had the lifters out wouldn't just looking down in there from which they came reveal cam lobe damage?
 
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Last Edit: 2017/08/29 08:26 By BikerRon.
 


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#1020835
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Re:Firing on one cylinder 5 Months, 4 Weeks ago  
davej wrote:
I think you guys are getting way ahead of yourselves with all this leak down and compression test crap. All the time you have spent talking about it you could have had the cover off the side and checked the cam to see that, that is your problem. Don't syke yourself out. Check the freakin cam already. I don't know why sometimes you guys make more of an issue than what it is. These bikes rarely have 1 major issue let alone 2 at the same time. It appears that the bike was running just fine before this happened and if the rings were bad it wouldn't have you would have had some sort of an indication of that. Also if the rings were bad it wouldn't make a cam go bad.

No offense but maybe the posts weren't read through very well. Thereís no reason to take the cam cover off to look at the cam. He said he has a dished out lifter with a hole in it, so the cam really needs replacing.

The question then came up whether the rest of engine was fine, and if so to just to replace cam and lifters. Someone mentioned it might be more economical to do an engine swap if there proved to be any other issues wrong with the engine. He couldn't perform a compression check because the valves weren't opening, so a leak down check was suggested because it's easy and effective.

I don't really see anything wrong with any of the reasoning so far.
 
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---------- NOTHING STRAIGHTENS MY HEAD OUT BETTER THAN AN ENTIRELY CROOKED ROAD-----------
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#1020901
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Re:Firing on one cylinder 5 Months, 4 Weeks ago  
Why would the rest of the engine be damaged??? Just because someone thru out some hypothetical "Maybe the tech honed the cylinders" means nothing. Especially chasing your tail. How about this "maybe the tech didn't hone the cylinders and the cam is just bad" You are correct you don't need to remove the cover to look down the hole to see a bad cam and you are also correct when you say that the cam is bad when finding a lifter with a hole in the bottom. Now the cover has to come off to change the cam so take it off read the manual and change the cam. Not really that big of a deal. Now you may find an engine for about the price of a cam set but after shipping my guess is that just fixing what is wrong (the cam) will be cheaper and easier.
 
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