Bonneville America Forums Forums Technical Forums Performance Mods 904 bb

just did the 904 bb just wondering how long i
should run the breakin oil before i go back to
synthetic oil i have 500 miles on the motor now
i am thinking this should have the rings seated
good enough what do you think.

maybe a few oil changes with the dino stuff and change around 1500-2000? just saying because its iron liners. i may be wrong tho

Frank

I'd change the oil now at 500, again at 2000, then go synthetic.

Or, I'd drop Wiseco a line get some advice. They built it. They should have some experience.

I would change and go syn. now 500 should be plenty to seat the rings.

thanks guys i thought 500 should be plenty to seat the
rings wasn't sure though, bikes running good didn't want
to go back to soon and start using oil,the bike seems to
run better and shift better on syn.i also have a set of
42 miks that i got from bill waiting to get a few more
miles on her before i put them on.frank how do you like
yours do they add a lot of kick to the bike.

my jetting still needs work. i am getting there. the bike starts better and idles better than with the stockers. they do take some getting used to, and i think i will feel more of a benafit when i do my bb this winter. for now i think i am getting there and i am getting 47mpg . i will give a writeup when i get them where i am totally happy

Frank

what jets and needls are you running and can you tell a
big difference over stock carbs.

stock needle with 150's right now, i am going to try 155's as the bike feels like it needs more on the high end. huge difference, need to learn when you can and cannot go wot but you get used to it. i am happy with them though

Frank

thanks guys for all the input.the 904 seams to run better
each time i ride it i hope the hsr 42's really bring it to
life she runs strong with the stock carbs they have 145 mains k&ns and SS pipes.

According to Wiseco they have seen no difference whether broken in with synthetic or conventional oils, I think part of it may be an urban legend regarding using conventionals for break in. I just finished my 904 as well, I have about 400 miles on it and I'm changing to synthetic.

The good thing about conventionals for break in is that they're so cheap, and you're only putting a few hundred miles on the oil anyway so why waste good synthetic?

Matt (mlesasard, the yute) is still running full dino after about 12k miles on his big bore, runs fine and it's cheap to change oil every 3k miles too.
The reason for dino oil - in theory mind you - is because synthetic is slicker and can slip past the new rings easier. I would not use synthetic for any breakin.

I broke in my BB-kit with dino oil on the dyno. I now use Motul semisynth (ester based) oil.