Partzilla Live Q&A with John Talley – September 17, 2021

Partzilla Live Q&A is back again with John Talley answering your motorcycle and ATV repair questions in real time.

Engine oil and break-ins came up a few times during this session. Check out some excerpts from Partzilla’s latest live Q&A session below, and tune into our YouTube and Facebook channels every Friday at 3pm Eastern for the next edition. 

Partzilla Live Q&A with John Talley 09-17-21

Partzilla Live Q&A Highlights – Engine Oil and Break-in

I just got a 2021 Kawasaki motorcycle and I’m coming up to my first service at 600 miles. Is the oil different after the 600 mile service? At the moment, it has the break-in oil. 

John Talley: It varies from manufacturer to manufacturer as to what type of oil or additives they may use for the initial break-in mileage. I’m a big believer in just using a conventional type of oil with maybe an additive, especially if it’s an overhead cam directly onto the tappets configuration where that goes through the break-in process correctly with the right type of modifiers. I can’t remember the types of modifiers I’ve used in the past, but that being said, I’m sure the manufacturers have taken this into consideration depending on which engine they’re dealing with. And after that, you’re free to go with the oil of your choice. I usually try to stick within the realms of whatever the manufacturer has suggested. I am a big fan of semi-synthetic versus just regular conventional. … Go ahead and use the oil that you want to use and I would recommend that you stay with it unless your machine is going to be in different environments as it relates to temperature. So if it’s a much hotter environment, maybe go with a higher grade oil as far as the weight goes, and if you’re in a cold environment, you may want to back that off a little bit as far as its operating range …

How quickly should break-in oil be replaced? 

John Talley: Every manufacturer gives a break-in mileage, whether it be for a race-type machine or a UTV or ATV or a cruiser or street bike and I go into the break-in process. For me personally, on a performance machine, I’ll run it in there for maybe 10 to 15 miles, maybe even 20, and then I take it out. Because by that point, especially on a performance engine, you finish the break-in process and you want to get all of that … all that slopped off material that comes off your rings and bearings and everything as they’re starting to meld together, so to speak, all that debris is flying around in your oil, so the sooner you can get that out, the better. 

I have recently rebuilt an engine and I measured compression with a test and it was at 4-bar. Is that low for a 150cc engine? I used a 10W-40 synthetic oil, but I’ve also ordered mineral oil. If I put that in, will it go up? 

John Talley: How long did you run the machine before you did a compression test on it? Because it’s really not going to give you a very accurate measurement until the rings have really seated. And as far as the oil, that really shouldn’t have anything to do with the rings once they’re broken in of course. I mean, if you want to break it in with a conventional oil, but then put a few miles on it, and then go back and check the compression. Is that a little low? Maybe a tick, but nothing to be concerned about if it feels right to you, because I’ve noticed in the past that not all compression gauges are well calibrated, and I’ve seen them be off as much as — I usually speak in PSI — but as much as 10 to 15 to even 20 PSI in between gauges. So you want to be a little leery of that, just because it says 135 PSI or 85 PSI doesn’t necessarily mean that it’s completely accurate. If you think it’s off, you may want to take another measurement with a different compression gauge to see what you come up with.


Want to see more live repair questions answered? See all of Partzilla’s Live Q&A sessions here.  


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