[fxdls110]

So, Ive got two FXDX bikes. One, a 99, the other an 04, carbed, and both have comparable mods.

The 99 has 37k miles, a Thunderheader, Big Sucker intake, stock pistons and SE 204 cams, and made 86 lb ft and 79 hp on the dyno.

The 04 has 56k miles, a Supertrapp 2-1 with closed end cap and 20 plates installed, Big Sucker intake, stock pistons, Mikuni HSR42 carb (50 AC pump nozzle, AC pump set to engage immediately and full travel, 98 needle with clip in middle, 17.5 pilot, 160 main jet) and, according to previous owner, SE 203 cams, which are close to SE 204s, from what I can tell by the specs.

The issue is that the 04 has noticeably less torque than the 99, so Ive been investigating why. First, I was thinking perhaps cam timing was off, so I did a compression test to see if there was a big difference in readings between the front and rear cylinder on the 04, as Ive been told youd see around 30 psi difference IF the cam timing was off a tooth. I also did both bikes, so that Id have a basis for comparison.
Firstly, 160psi is perfect for the 88ci motor from what can tell, with these cams installed and OEM headgaskets and pistons.
04 has 140 psi in both holes. 99 has 155psi in both holes. I dropped about half an oil cap full of oil into both holes on the 04, and the compression reading went to 150 psi.

So, if 160/100= 1.6, and bike should make 79 ish hp to the wheel and 79/100= .79 and 160- 140= 20/1.6= 12.5% loss which would theoretically be 10hp if the correlation between hp and compression is linear.
IS 140 psi enough to make this bike a slug in comparison to my other bike with 155 psi? I also was wondering if the crank case was filling with oil due to sumping and that was slowing it down, but I took it for a rip and then promptly pulled the plug from the bottom of the crank case, and only 1-2 oz of oil came out, so its not that.

Im going to perform a leakdown test tonight to see if the valves are sealing properly next. Im just wondering, the head gaskets are clearly stock, so Im sure adjustable pushrods were used in the cam install, and if theres major leakdown from the valves, could it be that the rods were adjusted too long and are preventing the valves from seating fully? If the rods were adjusted too short, could they be keeping the valves from opening fully, thus giving a false lower compression reading and also hindering performance? If either of the previous mentioned issues were present, wouldnt the valve train be noisy and perhaps have grenaded by now?

 

[Greg_E]

If they used adjustable pushrods, it would be easy to go through and figure out/adjust them to be correct.

 

[Uncle Salty]

The difference between 140 PSI and 155 PSI is significant and you would notice a difference in performance between two otherwise identical machines. Increasing the compression reading by adding a bit of oil to the cylinder is a strong indication that the rings are not sealing very well. A leakdown will help pinpoint where the compression loss is. If the pushrods were loose enough to not open the valves as you described, you would hear the clatter. If you hear air escaping back through the intake or exhaust during the leakdown you can back off the pushrod to determine if that's causing the valve to be off of the seat. Just be sure the cylinder is at TDC on compression and hasn't moved when you applied the air. I'd guess it's the rings based off of the info you provided so far.

One other thing I'd look for is the difference in gearing between the two machines. That could cause one to feel more sluggish.

 

[Don Dorfman]

Ok take the low one apart and have a look. My guess glazed cylinders and it never broke in right. Probably means oil by the rings too.

 

[fxdls110]

So I put the thing in fifth gear. I got the front cylinder close to the compression stroke. I put 5 PSI into the system and then I gently Rock The Wheel back and forth until there was no hissing out of the intake or the exhaust. I then had my girl hold the foot brake on the rear wheel so it could not rotate inject it to 100 PSI and with the main gauge reading 100 the other gauge was reading 97.5 PSI with no hissing out of anything not even into the oil crankcase. The exact same is the case for the other cylinder. So I do not know where my power is going.

 

[fxdls110]

I pulled the cam cover to check cam timing. With the rear cam sprocket dot on the line on the cam chest, the front cams dot is at 9 oclock. Thing is, theres no dot on the crank sprocket, so the fucker must be on upside down, which could mean the cams are lined up but the crank is not, so tomorrow i will pull the sprockets off and see.

 

[Greg_E]

Going to need a picture of this, not sure you can have the timing off that much without eating valves.

 

[tall terry]

pretty sure the crank dot is under the washer,, under the bolt...

 

[fxdls110]

I apologize, guys. I meant to say the front cam mark is at NINE oclock, with the rear cam sprocket mark on the line on the cam chest, and I edited it to reflect that. The mark on the pinion sprocket on the 04 very well could be under the washer. When I built a 99 for my girlfriend, the mark was on the tooth of the pinion sprocket, so I just expected the mark to be the same on this one, though Im aware they changed quite a few parts between 99 and 04.

 

[fxdls110]

Well i tore it down to do a 95 inch kit. Come to find out, the cams are cvo253, which close the intake at a whopping 54 degrees abdc, so no wonder its only reading 140 psi on the test abd no wonder its a slug. Those cams are for the cvo 103 of old. Hd has a pair of Andrews tw37b for 40 percent off, so ill just get those and take the heads down to 82cc or so abd it should rip like hell with flat tops abd around 9.6:1 compression. Sorry i bugged yall with that crap.

 

[rootintootin]

Just goes to show that you never know what you get when you buy used. Just because somebody tells you it has blah, blah, blah, means nothing.

The easiest way I can think of to be sure if you have adjustable pushrods would be to just pop off the clips on the covers and have a look. No guessing what's in there. Doesn't cost anything but a couple of minutes. But since you already have it torn down, you would know by now.

When I bought mine, it had a 95 kit with 37Gs and was good for about 85HP and 94TQ. But that was before the PO put on these Zippers Stage III CNC heads a year or 2 before I bought it.. When I did a few things to better suit the heads, I lost a lot off the bottom, but more than made up for it with mid to upper gains. The lines cross at about 3K and then the lights are out. I remember that it would take a lot more throttle to get things going, but I don't think about that difference any more.

 

[fxdls110]

Indeed. Its even got 06 heads on it so i cant even use the new Andrews valve springs and collars i bought for it. I just like to use fresh springs since im going to do a valve job and new seals while im in there. If i had know about the cams, ida just bought a set of 203 or even put stockers back in cause either woulda been better than 253s.

 

[tall terry]

99% of home builders will have a chronic mismatch of compression, cubic inches, heads/chamners//head work, and cam, and induction system,,, they dont have the knowledge to match the comonents,, and take the advice of a clue guys they know then end up with an engine like this one,,, no malice intinded,,, usually there are 3 4 rebuilds or upgrades trying to get it right,,, in frustrarion,, they sell it,, just a bad build,,, passed on to the next guy,,, you

 

[autoworker]

99% of home builders will have a chronic mismatch of compression, cubic inches, heads/chamners//head work, and cam, and induction system,,, they dont have the knowledge to match the comonents,, and take the advice of a clue guys they know then end up with an engine like this one,,, no malice intinded,,, usually there are 3 4 rebuilds or upgrades trying to get it right,,, in frustrarion,, they sell it,, just a bad build,,, passed on to the next guy,,, you

1%'er

 

[fxdls110]

Indeed so. Question, if anyone is interested-
would you happen to know which is better for the oil pump spigot and if they are made of different compounds- the 11293 oring or the 11157 oring? I sent my gf to go get me an oring from HD for the oil pump spigot, cause my top end kit did not come with the orings for between the pump and cam plate, the two between cam plate and engine case, or the one for the pump spigot. At work, I had all the orings in viton except for the one for the oil pump spigot. I am aware that the spigot oring and upper pushrod tube orings are the same size, and that the manual for 99- 05 called for the 11157 in the spigot and upper pushrod tube positions, but one manual called for the 11157 OR the 11293 on the spigot, and the parts guy insisted that the 11293 is for pushrod tubes only. I think he is incorrect and that the 119293 is the better of the two for the pump. Am I wrong??

 

[rootintootin]

My 2000 parts manual has 11293 for both places and doesn't even have 11157 at all. It also shows 11301 for the 2 between the case and the cam plate. Between the cam plate and the pump is a lot larger, 11286. You can find a different set of numbers if you look at some on line parts pages, but they have been known to have some errors, at least in my experience. I would trust my parts book, the dealer's parts book (same thing) or their on line parts books.

I like to use these guys as a quick reference, but I wouldn't bet my life on them being 100% correct. It is showing that by 04 the 11157 has shown up, but some of the other numbers have switched locations. I couldn't say which ones are interchangeable, but usually when an o-ring is superseded, they will change the color so you can tell the difference.

Ronnie's Harley-Davidson's 2004 Harley Davidson FXDX DYNA® SUPER GLIDE SPORT (GJ) | CAMSHAFTS ASSEMBLY W/ CHAINS Parts List

partsfinder.onlinemicrofiche.com

 

[fxdls110]

Hmm. So the 11157 is newer? The one they gave me is black. I thought the newest was yellow. Ive got thousands of orings at work. The big one betwen the pump and plate is a 136, the two on the left side engine case between the plate are a 110 and the one on the pump spigot is a 209. I had the 110 and 136 in viton, but not the 209. Im wondering if the older oring was made from buna and the later is made from viton. Both compounds can handle prolonged oil and fuel exposure, but viton has a much higher sustained temperature rating, and wont harden up nearly as quickly as a buna oring will if its living in a hot, oily environment, making viton the much better choice.

 

[Greg_E]

OK, so when I did my cam chest service, I ordered everything from Cyco, the o rings supplied were all the same size (5 for push rod tube and oil pump). Guess what I had to do, tear it back down to replace the pump o ring after it was sumping. The replacement o ring I bought was slightly thicker and fit the bore tighter. The push rod cover o ring initially felt like it fit correctly, but when comparing them the difference was easily visible. I forget which I ordered, but I bet it was the 11157. 05 88 Twincam A engine in FLHTCUi.

 

[fxdls110]

Thats the one they sold me 11157. So if thats the one you got, im good. Thanks!

 

[fxdls110]

And i will compare the cross section of the 11157 to the 4 pushrod cover orings i got with a pair of calipers.