Hey everyone, I have a 2009 Ultra Classic 96", it has 30,000 miles on it. When I bought it the power seemed to be lacking considerably. I did a compression check on the bike cold, I got 125 PSI on front and rear cylinders. That seems low to me, the touring FSM says minimum of 125 PSI. I plan on ordering a top end kit tomorrow, I just wanted to check here first to see if I am overacting. I already have it tore down putting cams in Wood TW-222, so doing the pistons and jugs isn't that much more. My pinion runout is 4 thousandths with a 1 thousandths play when lifting the pinion, so that would be 5 thousandths if I understand that correctly.

So some of you experienced motor folks, am I overacting or should I get a new top end minus heads?


Thank you, Jeff

 

In all honesty if you're using a less expensive compression gauge, it may just be reading low. A healthy stock (including stock cams) 96" top end should be in the 165 to 170 range.

 

Ohio HD, it was a Matco gauge. The bike seemed tired when I bought it, that is the reason I did the compression check. 125 PSI seemed low to me and has been in the back of my mind since. When I tore it down for the cams, factory lifter rollers looked good, little wear as well as the tensioner shoes. But, there was a very foul smell to the oil and very nasty to boot. Like the service on the bike was neglected, it also had a trailer hitch on it, so they might have ben towing with it.

Jeff

 

Maybe run a leak down test before you pull it apart.

 

Gotcha Ohio HD, I'll have to acquire a tester for that.


Jeff

 

You did do the compression test before pulling the cams?

 

No disrespect to the OP and a bit too late now but three requirements for an accurate compression test; both spark plugs out, fully charged battery, accurate gauge and throttle held wide open. Doesn't seem right for compression to be that low with only 30K miles on the motor.

Just a passing thought. If new top end is the next step, OP should consider boring to 3.938", fitting appropriate pistons to increase displacement to 107" and maybe manual compression releases as well.

 

Loanwolf176, I did. I did so because I felt that the bike was sluggish. This is my first 96" bike though. I've had 88" and 103" bikes. I currently have an 05 Dyna with a carbed 88" that will flat scoot. It will put the Ultra to shame. I bought it from the local HD shop and it was the Owners bike. I don't know what they did to that bike. But it is a power house.

The Ultra came with Vance and Hines monster ovals and factory breather with a SE filter. At the suggestion of Fuel Moto, I switched mufflers to S&S Grand Nationals, Fuel Moto AC/DC breather with a Dynojet tune from Fuel Moto. It does run better but doesn't feel as strong as it should. I've been concerned with the 125 psi since I checked it. It is in spec, though the minimum by the FSM. But looking at a compression and motor displacement calculator with the cams I now have. Shows that I should have a static compression ratio of 9.30 :1 with a corrected ratio of 8.78 :1 and cold cranking compression of 176 @ 600 feet above sea level.

Jeff

 

Djl, no disrespect taken. I did the test that way by the book. As for the 107", I thought about going that route. Only problem is, I already bought the Wood TW-222 cams and would have to buy a new set of cams to go with the 107". I thought about going 103" because my cams would work good with it. Problem is, I don't want to mess with the compression releases manual or ACR's. Also I can get the 96" factory upper kit for $380.

Jeff

 

Of course, boring to 107" is your call and I understand that it's easy for me to spend your money. According to my compression calculator the Woods 222 cams would work quite well with the 107" configuration if static CR is set at 10:1. The cost of boring to 107" would be about $600 including pistons and rings, so yeah, a bit more but IMHO, the cost/benefit is in your favor. I have never understood the "don't want to mess around with compression releases" comment as have heard that over the years from others that have never run them as well. JMHO but once installed pushing the release in is just another step in the start up procedure, like turning the ignition on or pulling the enrichener out if carbed. Considering the added benefit of extendng battery and starter life, I just don't uderstand the resistanace but you must have your reasons.

I think you could get by without compression releases at 103", with a flat top piston, static CR would be about 190psi which is the point at which going past brings compression releases into question. You may be concerned about compression, which I understand as I used to be; however, I have come to learn that these motors, properly tuned can manage higher compression. I am currenlty running a healthy 98" motor at 11.25 static and CCP at 213psi with no issues; I do have manual compression releases and use them on every start up.

Please don't take my comments as anything but me trying to point out what I think is a great opportunity for you to take advantage of the situtation and maximize the benefit to get that extra power you are looking for. You may have considered everything I have pointed out and, if so, apologies for the redundancy.

Please keep us posted on the project and the results.