I posted something similar in the oil forum, but this might be more appropriate to be asked here. My 2009 Street Bob never really used to use much oil. Not enough to notice. It's got 63,700 miles or so now and I haven't ridden it all that much the last few years. I thought I seemed to notice that it was using more oil than usual this year. I just changed the oil at 62,280 last fall and I've been needing to top it off more recently than what I thought was usual. I've been thinking of taking a trip with it so I've been scrutinizing the bike much more thoroughly and thought I should pay much closer attention to the oil consumption. It's been running very strong this year. I have been really kind of shocked. In fact, I questioned if maybe it had used more oil because I was riding it pretty hard around town.

So, I topped it off this morning and took a picture of the dipstick while cold to measure it against a level after some highway miles to see if normal highway riding would consume as much oil as romping on it around town. I hate to post exactly what I've found, but I would say if the dipstick is split up into 7 sections of X's from the 'Add Oil' line to the 'Full When Hot' line - I'm really poor at math, but say 1,000 miles divided by 7 is 142. So, if you rode 142 miles and you consumed one section of X your oil consumption would roughly be 1 quart per 1,000 miles?

The results of my test ride seem to indicate it almost eating two X's in what was a few more miles than indicated on the trip meter (I forgot to reset until after I left out), but safe to say just under the 142 miles marker which could equate to almost 2 quarts per 1k miles?

What could this be? Wouldn't the engine feel less powerful if the rings were worn - like lost compression or something? I feels stronger if anything. It's just drinking oil now compared to what it used to consume. It doesn't drip one drop of oil on the ground in the garage.

What would an estimate be to do a 'ring job' on one of these if it needed it? I'm just guessing that is what it might be. I have no idea.

 

Before you start freaking out about your engine you need to conduct your oil level measurements the exact same way every time. It's called a datum, and it means a common reference point for all information going forward.

First you say you took a cold measurement, then a hot measurement. Stop that! Do all measurements hot.

Also, put the bike in the exact same spot on the ground every time. Do you have a flat garage floor? Use it. Hell, even put little marks on the floor so your readings are consistent. Also, use the same chunk of wood under the kick stand. Holding the bike "level" is arbritary at best and heavily dependent on someone's feel of what's level. Unless you're physically putting a level on the frame rails of the bike every time to confirm it's actually level, your feel could vary by 10-20 degrees of lean every time, which could account for a discrepancy in your readings.

When I check my oil I use the same spot on my garage floor with the same block centerstand. I get the bike hot (5-10 min of good riding will do), pull in the garage to the same spot every time, prop the bike up, give it a few minutes to let all the oil settle and take the reading. If you don't have a centerstand just put some wood under the kick stand to make the bike more level. Not so much it could fall over easy, but enough to get the oil level marking higher on the dip stick.

Edit: Does the newer bikes like yours require you to center the bike vertically for oil readings? Or can you leave it on the kick stand? My Harleys both have to be centered, which is arbitrary since it's just a mark on a stick, who TF cares where the reference point is...

 

Matt has given you good advice.

Don`t panic, and don`t be afraid to take a long trip on that bike, even if it is actually using a quart every 1k, that is no big deal.

Some of the oil may be going out the breather system, the level may drop a bit after you "top it off", but it may stop dropping when it gets to a certain level, don`t let it get too low, but also don`t be obsessive about keeping the oil at the full mark. Halfway between full and add is good.

 

Honestly, I never even heard of checking oil cold before I got into a 2019 Mustang GT and with all of the drama surrounding the Coyote 3 I've had a crash course on various ways people keep tabs on things such as their engine oil level and some people do check cold just for consistency to see where the level is cold. I debated checking cold vs. hot for this test and decided it was too much hassle to get it hot and 'top it off' and instead I just 'topped it off' with it parked cold. Now, that may have introduced it's own issues of adding cold oil into the motor and taking a measurement before it got mixed up inside, but I'm guessing that is a negligible amount if so. I can't say definitively. I will try to check it hot vs hot in the same spot, but I was looking for a quick highway miles test.

For reference I noted the change at 62,280. That was last fall. So, it has set in the garage all winter, but it doesn't leak a drop. I have since topped it off with whatever was leftover in one bottle from that change and bought another quart and it's used all of that. I bought another quart yesterday just to 'top it off' again, but it really didn't need much. 1,400 miles burned probably a quart and a half or maybe a little less.

From the test ride yesterday it is now back in the exact same spot in the garage and it still looks like it burned about 1 3/4 of those X marks which to me calculates out to somewhere over 1 quart per 1,000 miles. It's not blowing smoke though. It's running great!

Here's the cold from this morning



What does an engine rebuild usually run though? Would I just want to do a big bore kit if I were going to tear into the engine anyway? What would be involved in that? I don't know all that much about engine rebuilding. Could you just increase the bore size with one of these kits? S&S 106" Big Bore Kit For Harley Big Twin 2007-2017

Or does it require the heads to be replaced too if you do that? I'm utterly clueless. S&S Super Stock Cylinder Heads For Harley Twin Cam

That makes it much less attractive to start adding all of that up. Harley does a 'long block' swap too I see, but it's like $4,400 for the 110" plus whatever it costs to install it. My bike isn't worth all of that I don't think. I could easily get a low mile bike for that kind of money if I wanted to continue riding. I might just want to wait for a Road Glide.

 

My '05 FXSTD was one of those with POS valve guide seals and consumed a quart of oil in less than 1000 miles from day one; only new Harley I ever purchased and I got one of those. Discussed with the dealer and the MoCo will look you straight in the eye and tell you that consuming a quart every 1000 miles is "normal" and not justification under warranty to repair. However, a technical bulletin was issued regarding the POS valve guide seals and mine were finally replaced. Took advantage of the situation and converted from 88" to 95" at the time. Both my Harleys require a " topping off" from time to time but I don't lose any sleep over it, I just keep the oil where it needs to be.

Don't hesitate to take a trip on the bike; as Dan points out, the consumption may drop off once it reaches a certain level. Just throw a bottle in your saddle bag in case you have to add somewhere along the way. Additionally, don't be confcerned about mixing brands, weights, syn or dino along the way; it makes no difference.

As for a rebuild, the cost will depend on whether you turn the wrenches or pay someone to do it. It should cost about $500-$600, to bore/hone your cyliders, gap rings and fit pistons to cylinders; another $150 for gaskets, oil, etc. If you outsource the labor, allow 8 hours at whatever the going shop rate is in your area. At 62K miles, your heads should be cleaned up, valve job and new guide seals, probably another $250-$300. If you decide to have the new top end tuned, add the cost of a tuner and the dyno tune. That's about the minimum, ported heads, aftermaket BB kits, cams, hi-flow air filter, etc. and the cost increases significantly.

You say the bike is running great, so take the trip, keep the oil at the level Dan suggested and deal with the oil burning when you return.

 

Good call DJL, I was also gonna say valve seals, and do a leakdown check to see how the rings are holding up. Commonly the Twin Cam at that mileage is starting to grow a little worse for wear but still fully functional.

 

Thanks for the advice. I asked a local indy shop and they seemed to think that era of bike was bad about burning oil through the breather/intake from the crankcase - whatever, you know what I mean. I've seen they make little air/oil separators for these. I pulled the plugs and the air filter to take a look. The plugs should be fairly new and they look pretty normal to me. They don't look like they've been burning oil anyway. The filter element is just badly in need of a cleaning, but it didn't pour out a quart of oil when I removed it. I'm going to clean it up and put it back together and ride it some more next chance I get and try to monitor the oil level and see what it's doing.

It kills me because I just did the front and rear bearings myself with the Pit Posse toolset and it came out pretty nice. I replaced rear brake pads even though they would have otherwise been good for the season probably, but I just didn't want to get caught on the road with something dumb like that worn out. I ordered a new battery and installed it today. I've got a new front motor mount coming that it might otherwise live without, but I thought I would do it preemptively too. The bike is running fantastic.

Tell me if anything looks out of place to you guys in these pics:

 

Plugs look OK to me, not showing oil fouling. However, the oil in the air filter/housing indicates head breathers not functioning properly. At 62K miles the umbrella valve in the old type breathers may be hardening and leaking. Consider replacing them with the later (2011 IIRC) stamped breathres (PN 17025-03A). They will come with new bolts and are said to be more efficient. You appear to be a DIY guy so replacing the head breathers with the new ones will be a piece of cake. I remove the tank when changing them but really raising the tank is all that is necessary. The front one is easy, the rear a bit more challenging because of the limited work space but they will come out; just have to play around with it. The new breather kit will come with new shorter bolts and is much easier to R/R.

If you are so inclined, venting the new breathers to the atmosphere would also help but, at a minimum, change the breathers and see if that helps oil consumption; parts are cheap and the R/R is easy to do before taking the planned trip.

Of cours, the oil could be getting by the rings but, as has been said, a compression and leakdown test will better inform the condition of the top end which can also be dealt with after the trip. Having said that, your situation should not deter taking the planned trip.

 

I've never cracked a motor open. There are motorcycle mechanic school videos for the twin showing how to do it. I just bought the service manual too. Can those rockers come off while I'm replacing the front motor mount?

 

Those plugs look a little ashy to me. You might be burning a little oil.