An ole bike mechanic that I know and has some of the healthiest bikes around swears by diesel oil, especially for air cooled bikes such as the Sportster.

 

The oils most of usare using are diesel rated oils as designated by the letters "CF" on the back of the bottle.

 

I didn't switch to Syn oil until 10,000 miles. Not really because I bought into the theory that you should wait to make the switch, I just didn't get around to doing it until then. But that also gives me a broader number of miles to compare the bikes performance with Dino oil versus Syn.

I've now logged a little over 10,000 miles since I switched to Syn oil. The engine runs slightly more quiet.

It runs significantly cooler, and this isn't just a subjective thing where I "think" it's running cooler, I have an oil temp guage. In the 90 + degrees we've been having lately, my bike is running about 45 degrees cooler than it did last summer when I was running Dino oil. I was still running with the lean carb setup last summer. But when I first made the change to Syn oil, in more moderate temps, the bike was running about 25 degrees cooler just from the switch to syn oil.

I also switched to Syn for the tranny. That improvement was immediately noticed. By the time I got out of my subdivision, I couldfeel a big difference in the shifting. It is much smoother, and you can just tell the tranny and clutch are more happy. I've heard some good things on here about running Syn gear oil in the Tranny, I think I may give that a try at the next service.

Oh, the Syn oil I'm using is the Mobile 1 v-twin 20w 50 in both holes.

A word of caution.........Don't follow the service manual when it comes to the amount of oil to use.

You will only need 3 quarts MAX including a few ounces you pour into the filter. If you use the amount listed in the service manual you will over fill the engine and get the dreaded oil blow by leak through your air cleaner. Trust me, THAT SUCKS!!

The amount listed for the tranny is correct. Exactly one quart in the tranny.

 

so am I safe to say that since my oil tank has oil in it right up to the opening that it is overfull? I hav thought that it was, I am going to take some out (creatively) but how much should I have in there. I have about 1850 miles on the bike, it is a 93, I don't want problems with the engine, and I was thinking of switching to synthetic, and by the sounds of it I am smart to do so. When I will also do the suggested when I change my primary.

someone posted on hereearlier in the thread that they "pour oil into the filter" and use 3 quarts max,can someone clue mein,(short explanation) on oil changes, I hve only changed oil on rockets, never on a harley

 

Slackwolf, I've logged 1500 on my sportie and plan to use conventional oil for life. I have been told by many long time harley owners that the synthetic will break down your seals FASTER. Just the rumor mill. I also stay away from synthetic in my car and I have 318,000 miles on it and I have owned it since it was new in 1997. Yeah cars are different, but I think synthetic is overrated.

 

I just changed the oil in my XLC 1200 for the first time yesterday. I put in 3.6 qts as the manual said. I did notice that the tank seemed very high. I thought I was just using the dip stick wrong. I'll check it again today . Glad I read this thread this morning.

 

Get your wife's Turkey baster, it will work great to suck out the extra oil. If the dip stick is at the full mark, it's over filled. Of course the MoCo, won't admit to this, but I'm sure some others here will echo that opinion. I run mine between one quarter to a third distance between the add mark and the full mark on the dipstick.

Prior to adopting that practice, I blew a LOT of oil out through the air cleaner.

Oh, almost forgot ya bobsterkid, it's a good practice to pour 3 -4 ounces of oil into the oil filter before you install it. That way, when you start the engine, it doesn't have to suck oil all the way from the oil tank before the engine gets some lubrication.

 

Hmmm....the mention of oil seal degredation has made me think twice about synthetic oils.[&:]

 

switched the bike to mobil 1 v-twin 20w50 this morning at 2580mi, and have rode about 65-70 miles today. Seems it quieted down a little bit of topend noise when cruising at higher rpm's. Wasn't very noticeable running the H-D 50w to start with but seems to have toned it down more. I don't have a dipstick temp guage but just the amount of heat coming off the engine, I can tell between the PCIIIusb from fuel moto and switching to mobil 1 synthetic, the engine is running much cooler. I bought 4 quarts of the mobil 1 v-twin and only used 3 during the oil change, so am planning to get the gaskets/o-rings I need and change the trans/primary also.

As far as the 3 quarts MAX for crank, lol yup..... let the oil tank drain for a while (45min-1hr roughly) and moved it around a little to get some of that straight 50w that was left in the tank. put about 4 ounces in the oil filter and gave it time to soak in, and put it on. not thinking I got on a roll and dumped in the remaining quart from what I used to fill oil filter, and 2 full quarts.... sure enough, when I check the oil level while hot after about 30-35miles of riding, oil level is on the full mark... doh! so probably going to pull some of that out tomorrow. was running at about 3/4 to the full mark before and didn't seem to have blowby problems. If I would have used the specifications from the manual, I think I would have almost topped off the oil tank. lol it's funny that the harley stealer charged me for 4 quarts of 50w, and another quart of formula+ when they screwed up my 1k, but yet the oil level was lower than what it was when I used 3quarts.

1 week from monday I'm planning to order the V&H shortshots staggered and undecided on which aircleaner, then get new map from jamie at fuel moto. still can't decide what air cleaner I want to get lol been eyeballing the NRHS hurricaneflow and doherty powerpacc, but price is still making me look around. Anyone know if those doherty powervents are really worth it to help the blowby problem? wonder if could run the oil tank at full mark and still not have any blowby problems running those lol


Edit:
Just went out and checked my air cleaner..... sure enough, had some oil burping out and going into the a/c. bottom of air cleaner had spots of where the oil had soaked into the filter and inside of filter had a little oil mist in there. So I figured I'd put that syringe that came with my fish cooker/shrimp boiler pots to use and pulled 7-8oz of oil from oil tank. right now, oil level sits at around 3/4 between fill and full, between the H and O where the dipstick reads HOT. Where does everyone else keep their oil level to prevent oil from burping up? I think running the 50w it was somewhere around the H on HOT, but figured would leave the level alone for the night and see where everyone else runs. I'm curious about those doherty powervents that can get with the doherty powerpacc. I'm wondering how well they work as it would be nice to be able to run the oil tank to full mark or very close and have that extra capacity, while not having oil burping out.

 

Synthetic oils don't really cause seal degradation. Here's where most of those stories come from.

In high mileage engines, gaskets and seals will eventually get old and fail. Dino oils have the nasty habit over time of leaving behind sludge deposits in your engine. This sludge/crud tends to build up around the edges of the gaskets and forms a sort of seal. This buildup can mask the fact that the gasket has dried out and needs replacing. Synthetic oils have a high detergent property that helps prevent and also remove the sludge buildup. This is why some people report that synthetic oil made their engines leak. The syn didn't really make the seals leak it just uncovered an existing problem.

Personnally I would rather not have the sludge in my engine to begin with or rely on sludge to keep my engine from leaking.

This is the reason people tend to recommend switching to syn. oil early on rather than in high mileage engines.