Crankshaft and Main Bearing lube

[florida derbi rocket]

Hey Everybody.. I posted in The Derbi Section..but since I have one of those Spanish scooters, I didn't make it into the new posts. (No offense intended here)...So..I am starting a new thread that I think is relevant to anybody whom is a serious Mechanic..and is Rebuilding any scooter Engine from the crankcase up.....As I originally posted ..I Got A theft Recovery that was Thrown into Salt water..(READ LOTS OF SAND!!) I have lovingly Cleaned and Dis-assembled this Derbi Atlantis (2002 ...1081 Original miles..For $300 Bucks) I have even Pressed out the Main Crankshaft Bearings and ordered new Rubber seals...Anyway.........I had a "DUH" question...Do I "Pack" these Main Bearings with Bearing Grease? ( I have The Most Excellent Permatex Industrial Synthetic...With Teflon..[ Clear ] Bearing grease) to do this with.. I am just double Checking ..I know enough about scoots..that certain areas are to remain dry...and The 2 stroke Oil alone lubes certain areas..Again..The Only Dumb Questions, are the ones you ask after You Seize!! (2 -Stroke Humor) I appreciate anyones Input!! Thanks ..John From Jax :D

[XPS1210]

Double check with where you get them but they should be "pre-lubed" or a dry bearing...

I can't see packing them as the inside of the case is dry...

Lennox, you just did a open case build... was there grease in the bearings?

[florida derbi rocket]

Hey Jered..Thanks for replying so fast..(I am in the Shop with my hands Dirty!!) I didnt order new bearings..Just new rubber seals..When I dis-assembled the Crankcase...I Swear I had Bearing Grease in the section that the oil pump was in...matter of fact..I cleaned bearing Grease off of the pump as I saw the Cir-clip and Gear that I want to remove as part of Your Mod..(It was Yours wasn't it?)To Go to only pre-mix..Anyway..There was so much sand and salt water in here that I couldn't tell if the Variator side was packed..In fact..I couldn't tell if either side was packed..I have my doubts that this Crucial Bearing runs Dry..And I don't see any way for the 2-stroke Lube to get to these bearings... My Old 80's Dirt bike 125cc experience tells me to lube these..Again..I am just being Careful and asking..Thanks!! John From Jax :D

[XPS1210]

There was a little "grease" on the gear for the oil pump but not much...

Donno... I thought they were the type that were "sealed" bearings where they were pre-greased...

However I haven't done a tear down yet...

Unfortunately Lennox hasn't been on since you posted... So when he does he should be able to spread more light on the subject as he did a split case upgrade and would be able to tell you if they are grease (by packing it) or if it is a sealed bearing...

[Lennox]

the main (crank) bearings are lubed by your oil mix. When re-assembling you should coat lightly with watever oil you plan on runnoing. Bearings are relatively cheap.... if it had all the crap you say, why not replace them? Are you going to use anything on the new crank seals? Yamabond? I use 3bond. I just got back from Pa, and am trying to catch up a bit before going out for new years. I will be catching upo in more detail tomorow. Pm me if you need anything.

[florida derbi rocket]

Thanks For the Info Lennox...Actually the bearings were in pretty good shape...Even clean and dry they spin very easy . I didn't even know those seals are glued in..I will stop at a motorcycle shop and get something to glue those with. I am going to run fully synthetic oil in this Scooter. .................Thanks again !! John From Jax

[Lennox]

John, how is the needle bearing where the rod connects to the crank? Any play?


technicaly they are press in only.... since you need the 3bond to re-glue the cases anyways, Alot of mechanics I know, and myself, put a bit on the seals as well.

Sounds like your getting close.......

[florida derbi rocket]

John, how is the needle bearing where the rod connects to the crank? Any play?


technicaly they are press in only.... since you need the 3bond to re-glue the cases anyways, Alot of mechanics I know, and myself, put a bit on the seals as well.

Sounds like your getting close.......
. Lennox...There is a tiny bit of play..but it might be a result of knocking the crank out with the wood and hammer method..salt water had everything a little cranky (no Pun) The play seems to not be the needle bearing..But a little sideways movement( less than a milimeter)...I think the crank (lobes?) can be pressed tighter together taking care not to bind the Rod (oh so carefully) Does the bond go under the gaskets on the case? Thanks again Fellow Floridian..John :D

[florida derbi rocket]

Sorry..I don't mean to fish for a reply..But Jerd and Lennox..i still need your help..See last post Questions..(Not An Impatient Dude) John :rolleyes:

[XPS1210]

I don't have that answer other than I'd guess it shouldn't have play as it's a bearing and shouldn't move side to side... However since I haven't gotten into it that far (splitting the case) you'll have to get that one from lennox...

[Lennox]

should be VERY LITTLE play.... and no, you cannot tighten it

[florida derbi rocket]

Well ...I'm Ordering Main...And....... Rod needle Bearings..I took the Crank to a machine shop today..And a Friend looked at it for free..he is too busy to Polish the Arms..But he said to replace the needle bearing fo' sure..He said it is not hard to seperate the Lobes...Just to use a Brass or Hardwood "Drift pin". He got called away before I could ask about re-assembling the lobes..I think he thought the Vise Idea was ok..If I was slow and Careful..(Cause I Told Him About using Big Sockets And A vise to Press out The main Bearings) He also Told me about some local 2 Stroke Go-Cart Racing Guys to talk to about General 2 Stroke re-build Knowledge??.....I am Slow and carefull guys..My Dad used to own a steel Fabrication shop and I have some of this general Metalurgical Knowledge..(about Tolerances and not stressing steel or aluminum) Thanks for your Input..John