Multi-Weight Oil Loss on Ironhead...

[Hrdly-Dangrs]

I did an oil change two weekends ago about a half hour prior to leaving for the Jersey Shore. (I live up here in North Jersey)

For some reason????...I decided to go with a multi-weight oil (Castrol 20-50 Multi-Weight) the 4T Motorcycle specific. I normally use their 50 straight weight, but could not find any locally at the time. Hence the purchase of the 20-50wt at the Pep Boys store....(Although they did have Straight weight 50 motorcycle oils in Valvoline, Lucas and Purple in various Dino and Synthetic types, I went with the Castrol multi....again I don't know why.

First thing I notice after kicking it over was a lower cold oil pressure reading. No problem...It showed good pressure, just not as high as the straight wt when cold starting.

We took off on the bike (riding two up that day with the wife) the next thing I noticed about 20 minutes into the ride was a definite quieting down of the top end valve chatter. Temprature outside was a balmy 80 something. I thought, hey this is great. Oil pressure looked about the same...you know just above '0' on the oil pressure gauge...got one of those auto type oil pressure gauges which refuses to show small increments of pressure...basically serves as a fancy idiot light.

Anyway...got to our destination....about 2.5 hours of straight riding, checked oil level...looks good, little lower down from the top notch of the dip stick, no problem, this bike always uses a little oil thru various leaks...Harley you know.

Next check back home after about a 6-1/2 hours of almost constant riding for a total of about 9+ hours of riding time. Again a little lower, no problem.

Went for a short trip of about 75 miles last weekend, parked the bike and forgot about it. Go to start up the bike yesterday afternoon, checked the oil level and whoa!!! ...the oil level is down to just below the lower notch of the dip stick....???

That's at least a good Quart+1/2. I started the bike to see if maybe the oil had weeped past the check valve and was laying in the sump...Let the bike run approximately 5 minutes, re-checked and nope, levels the same. I will take the bike out for a short ride today and see if there is any significant return of oil to the tank.

If not, my conclusions??...The 20-50 wt definitely helped quiet down the top end.....but oil consumption was up significantly over the 50 wt straight oil of the same manufacturer and/or the 20-50 multi wt oil tends to leak past the check valve...which the straight 50wt never did.

Anyone use multi-wt in their Ironheads with similiar results??
I was thinking of going with a multi-wt synthetic oil next chainge like Lucas or Mobil/Castrol, but now i'm not so sure. Hrdly

[Kojack]

The way it was explained to me years ago was that multi-vis oil like 20w-50 is a 20 weight oil with the lubricating properties of 50w oil at operating temperatures. It should lubricate better when it's cold and the same when it's hot as a straight weight oil, right? I tried Castrol 20w-50 in my shovelhead and noticed an alarming increase in oil consumption. My hydraulic lifters didn't like it either and started clattering intermittently when hot. I talked to the guys at the Harley dealer about this. They told me that Harley sells both straight weight and multi-vis oils but they DON"T recommend multi-vis for pre-evo motors. They couldn't tell me exactly why but it's known that the evos have much better lifters. I'm back to straight 60w Valvoline. The lifters still throw a fit every once in a while though. I always had 20psi when hot at idle with either oil. I'm pretty sure your Sportster has solids so that shouldn't be an issue but I think I'd stick with Harley's recommendations.

[Hrdly-Dangrs]

Kojack, Yes solids lifters.

I read numerous articles, threads on the net about multi-wt versous straight wt oils in the older harleys. None really have any confirm conclusions as to whether you should use either of them and the debate on the synthetics are even more crazy.

Anyway, thought I'd give it a try......If the oil isn't laying in the crankcase having bled past the check valve ball, then I know its definetly back to straight wt. Then again, if the oil is in the crankcase, maybe its time for a new ball/spring in the pump.
The valves definetly did quite down over the heavier straight weight...which has to be a good thing I would think...those oil lines to the head being so small/narrow...Hmmmm???

I used to always use Valviline 70 Wt Racing Oil many years ago. Remember that oil? Something about the 'Racing' word in that line always appealed to me back then...even to this day.....just a big kid even now...must be why I still collect those old oil cans.

I see Valvoline now has a motorcycle specific oil too. Of course there's the whole debate over whether there truly is any differance in regular auto engine motor oil viscosity compared to the so-called motorcycle specific types also.

Lucas oil also has motorcycle oil too...Anyone ever use that brand? Hrdly

[Kojack]

Other than the experiment with the 20w-50 Castrol I've been using the Valvoline racing oil for years, mainly because it's so easy to get. The Autozone is only 3 miles out the road. The "racing" part of the name seems to actually be more important these days. From what I've been reading, regular oils have cut way back on the zinc anti wear additive that's important to motorcycles. Racing oil still has it. Amsoil has a line of motorcycle oil and since a buddy of mine is a dealer I bought a few quarts of their straight weight but haven't tried them yet. I figure that I won't notice any drastic changes using any straight 50w or 60w. I contacted Lucas a while ago and they suggested that I use their oil additive in a 20w-50 oil but I never tried it, I'm still leery of the multi-vis stuff. As a side note, I mixed some Marvel Mystery Oil in my oil tank with one of my changes and it quieted the lifters down completely. The intermittent tapping came back after I changed it out the next time though. This seems strange since the Marvel shouldn't do much except thin the oil out. One thing for sure, it makes the exhaust smell good, a little like wintergreen.

[Hrdly-Dangrs]

I use Marvel in my gas tank as an upper cylinder/valve seat lube. Does it work??....Hell I don't know for sure, just something I've been doing for many years.

I seen that Lucas additive at the auto store when I was looking thru the oil section. Suppose to thicken the oil and increase lubricity or viscosity or cling I think.

Think I'll start a Thread on Gas & Oil Additives.... Hrdly

[Hrdly-Dangrs]

Well, ran the bike about five miles up the road. Oil level just above lower notch on the stick. Stopped and checked the oil level.....same...returned home and re-checked but still no significant return of any 20/50 wt oil to the tank.

If there were any oil in the crankcase it should have been scavaged back up into the tank. Appears the motor just blew out that multi wt oil over the previous 300 mile run a couple weeks ago.

After returning home I put in a quart of Valvoline 60 Wt Straight Racing Oil. Went out for about an hour or so. There's a section of 2-lane blacktop that ends at a stop light and becomes a highway. Its straight and has a slight rise to it. Perfect for testing out plugs, timing and jetting. I took the opportunity to do a 1/4 mile full throttle run off a stop light. Bike pulled great and front wheel left the ground on 1st and 2nd gears. NICE!!

Anyway...my conclusion....I will never ever use a multi-grade oil in the Ironhead again. Not that it did any harm as I had good oil pressue the whole time....but the oil consumption with the multi-wt 20/50 grade oil is just to high.

Think I'm going to try out the Lucas Straight Wt 70 Racing Oil.
Its still pretty hot weather here in North Jersey for the higher wt oil. Hrdly