Hey guys,

I'm a shade tree mechanic. I retired a couple years ago and being fairly mechanically inclined, though never formally trained, decided to rebuild my 2000 Dyna Wide Glide on my own. I rebuilt it from the crank up, every bearing, seal, gasket, but, bolt and etc. has been replaced. I fired her up yesterday and she seems to be burning oil on the forward jug. What could be the possible cause and solution? Oh, I did increase it from an 88" to a 95"

My thought was maybe the jug is worn and needs to be bored out a little, like .1 over?

Thanks!

 

Did you break it in? The rings need to seat. Usually takes 10 to 20 miles of proper break in for this to occur. Until then there will be significant blow by.

 

What is the evidence of oil burning in the front cylinder? Could have a ring upside down or even broken; oil ring improperly installed?

Need more information on "88" to 95". HD BB kit, bored OEM cylinders to fit new pistons? How did you get from 88" to 95"? The above break in question needs to be answered as well, but the fact that the issue is isoloated to the front cylinder, I am more inclined to think something is wrong on that cylinder. I have not experienced "significant" blow buy until the rings seat if a proper break in procedure was used.

 

A few years back I dropped a valve on the original motor. I bought a 95" motor from ebay and swapped out the motors, the 95 ran great. The work was done by a Harley dealership. When I rebuilt the bike I took the original lower end and mated it to the upper off the 95". The only thing I didn't replace was the valves and springs.

When completed I started it up and did a break-in method I found on this site. Starting on the stand, letting it warm up with a fan blowing on the jugs, varied the RPMs, let it cool. Then took it for a 23 Mike ride, varying the speed, including some hard acceleration to seat the rings. It started burning oil and leaking at the head gaskets. I'd put them in, had to reopen and tried to reuse them as they hadn't been heat treated yet. I'm sure you know how that worked out.... Anyhow, so reopened and put in new head gaskets. Starting back up get some blue exhaust and if you rev the engine a bunch of dark exhaust came out. I shut it down and let it cool then checked the plugs. Rear plug was clean, but forward had some wet black substance on it. Presumably oil with a bit a fuel? As it was not thick like standard oil.

I suck even more at technology but I believe the link below will take you to my Instagram where there is a video that wouldn't upload to the forums.

 

Sure looks like burning oil and/or fuel.....

How was it rebuilt...??? "Rebuilt engine" means different things to different people...

Some people only consider a cases spilt, with new crank work up to and including headwork and fuel delivery work... as a rebuilt engine...

Adding pistons and cylinders onto an old bottom end, is only a top end rebuild.... That is if the pistons, cylinders, and heads are all measured and matched...

If the top end isn't properly measured and matched, it's not a top end rebuild, it's just bolting parts (new or old) onto and old bottom end....

" When I rebuilt the bike I took the original lower end and mated it to the upper off the 95". The only thing I didn't replace was the valves and springs."

Forgive me, I am not at all trying to be condescending, but I know nothing about you​​​​​, your knowledge, or your experience.. So what does that statement mean to you...? If you are experienced with HD engine maintenance and repair, and a rebuild is something you've done before... forgive me and skip all the following questions, until the last two paragraphs...

If you are not experienced in HD engine repair, or rebuilding, these questions are to let you know what goes into a rebuild, and the many steps needed to avoid issues like you are having...

Did you split the cases on the old bottom end...? Or is it OEM and you just put new 95" pistons, 95" cylinders, and the newer heads on the old OEM bottom...?

Did you buy new pistons and fit them to the cylinders...? Did you hone the cylinder bores or bore them out to fit pistons...? New rings..? Are the pistons the exact same make/model/size as the ones removed...? Was the compression changed at all...?

Were the heads from the 95" OEM 88" heads or did they have work done to them...? You didn't replace valves and springs, but did you do a valve job and replace the valve seals..? Did you have the heads measured and then shaved to balance the chambers??

Very curious that the head gaskets both failed on start-up. What type of head gaskets did you use...?? Did you use the HD method of torque finished by angle, or the Cometic technique of 5 steps, the last at 42 ft-lbs...?

You didn't state year of bike and/or various engine parts... but sounds like you are working with an 88" to 95" big bore... Is it carb or EFI...?

With all these changes, did you use the same cams, pipes, intake, compression, and displacement that were on the bike for its last tune....??

Did you retune it if any changes were made above...??

Sorry for all these questions, but the answers to all these question are needed, for someone not involved in the build, to guess at the cause of your specific issue....


Something doesn't seem right, but there is not enough information on what your "rebuild" entailed for most to hazard a guess, other than just listing the many things that lead to excess oil burning and/or excess fueling...

If your rebuild was done well, with best practices used, to proper specs, and based on what you have shared so far..... IMHO, the best guess was from djl that there is a problem with the rings on the front cylinder...

Yet.... in the video, both cylinders look kind of suspect to me...

At the very least, I would be doing a compression and leak down test, before opening it up to check things out... It might help pinpoint where to concentrate your efforts during inspections...

Good luck and keep us posted on your progress....

 

I don't have as many questions as hatitude but do have a couple. I do agree compression and leak down tests will probably reveal something but I would cut to the chase and pull the front cylinder; it's coming off anyway.

We know it is an earlier model being 88" but model year and any other modifications could help.

I took the original lower end and mated it to the upper off the 95". The only thing I didn't replace was the valves and springs.
So, if I understand the rebuild, you used the lower unit (crank case and flywheels) from a good running 95" which was the original lower unit with the factory VIN which I understand. Dropped that lower unit into the frame and installed the top end (heads, pistons and cylinders) from the Ebay 95" motor which was running good with no issues.

The comment about replacing everything but valves and springs would indicate that you replaced pistons and rings? maybe the head breathers? So, if pistons and rings were replaced there could be several different sources for the oil burning. New piston fitment to the cylinders, ring installed upside down, oil ring installled wrong, and or broken ring. I must assume that valve guides and seals are OK since there was not oil burning in the Ebay 95" motor?

Answers to the questions that have been posted will help us help you.

 

Thanks for the assistance, if I forget to answer anything I apologize upfront.

In doing my rebuild I followed the HD shop manual for the bike, a 2000 Dyna Wide Glide, carbureted. It had 148,000 miles on it, if that helps with anything. When specialty tools were needed I ordered them and waited.

​​​​​​The engine rebuild consisted of splitting the case from the original 88" and replacing the bearing on the fly wheel and o- rings. The pistons, jugs and heads were reused from the 95" I got off eBay. I think that was off a wrecked 05 Dyna, can't be sure I recall correctly though. I did have the jugs honed at a local shop and I did replace the rings. I didn't do anything with the heads other than clean the carbon up a bit. Maybe I have a leak on the valve seals??? I didn't mess with pistons either, just the new rings. I did follow the instructions and am confident I didn't install the rings upside down or pinched them, but it is possible.

I don't know how to mess with compression and other things. I'm not a speed demon. I'm a long hauler and rather ignorant (obviously), but with a lot of time on my hands. So, I've been trying to rebuild to spec with the exception of the 95 vs. 88". I reused my cams but replaced lifters, oil pump and camplate from Fueling, used Anderson adjustable pushrods. Carb is a Mikuni HSR 42 and also new and I still have two more adjustments to make on it, but stopped to figure out the oil leak.

I haven't done any tuning yet. Just got done rebuilding, started the bike, did the little rise when oil burning was noted and here I am.

Did I get everything?

 

Thanks for the additional information. JMHO but based on the information provided so far, I still lean to something wrong with the installation of the Ebay top end. Cylinders were honed without a proper measurement of piston to cylinder fitment so the front cylinder could have been honed beyond service limits. I am assuming that the 95" kit work that was done by a dealer included SE flat top pistons which would be typical for a dealer installed kit. Those pistons are hypereutectic and require tight piston to cylinder fitment, like .0015".002" IIRC; pretty tight. So, if honing removed enough material to open the piston to cylinder fitment up to say, .004", that could be the problem. IIRC, ring gap factors for hypereutectic pistons are different from forged so ring gap, particularly in the oil rings could be a problem. Then there remains the possibility of a ring installed wrong; happens quite often and the results are just what you are seeing.

Compression and leak down tests are very straight forward, just need the proper tester.

 

I think dlj is right on target with piston fitment and/or a poor hone job.

 

Not to be redundant but like hatitude said based on the exhaust it sure looks like it's both cylinders. Maybe the front is worse but the rear is definitely puffing some smoke too. I hate taking newly built stuff apart but it sure looks necessary here. I hope it's an easy fix for you...good luck