1978 YZ250 oil and gear lube?

[BusyLittleShop]

A 1978 YZ-250!! Just like Bob Hannah used to ride! Oh, how I used to want one of those...with that big aluminum mono shock swing arm...

Even though I owned and raced a trusty Husky I always got a kick out of watching Bob "Hurricane" Hannah at the Superbowl of MotoX L.A. Coliseum kicking Team Husqvarna's butt and at Reno Bob raced VooDoo Chile with the same win or bin intensity...

MayDay
Bob almost augured to his death in 1999... He describe to me that in
Saturday's heat race the left elevator trim tab jettison clean off the
airplane at 450+ this caused a violent pitch up subjecting him to over
10 G's of forces... mercy!!! this caused him to black out and when he
came to VooDoo Chile had zoom climbed to angels 9,000... A little
shaken and disorientated to say the least but Hannah got the whole
mess under control and made an uneventful landing... Bob was pissed
because structural damage kept him out of Sunday's championship
competition.

 

[cknight49090]

went to local WM had nothing the only thing i saw was some mobil motorcycle oil and it was 15w40

 

[Lyman]

Check the pipe too. I have seen them clog up running oil rich mixtures

 

[cknight49090]

WM online has castrol 2 stroke and motorcycle oil for gearbox for less than 10.00

 

[cknight49090]

this is what i decided to use based on availability and price what do you guys think ?

 

[Alain2]

You can’t go wrong with these two Castrol products, they are both certified JASO.

 

[cknight49090]

thanks i figured so i had a 10.00 coupon bought these two bottles a 4 in by 25 ft snatch strap and 2.5 gals of purple power for under 30.00 delivered with the10.00 coupon.

 

[Cujet]

Castrol go 2t is certified JASO FB and is an excellent oil for air cooled application. I have personally tested Castrol 2t in one of my Yamaha RD400 and it worked great.

It's good to note that the FB classification is as good as two stroke oil testing gets, with regard to lubrication. The FC and FD specs exist for smoke and deposit reasons, not for additional protection. With that in mind, any FB, FC of FD oil will do well in your bike. Again, it's the oil ratio that provides the protection.

Quote:

"The general rule for the different performance levels is this:

• FB corresponds to high lubricity performance but without any low-smoke technology.
• FC meets the FB lubricity standards but also is a low-smoke lubricant.
• FD corresponds to higher detergency properties than the other two grades, meets the lubricity requirements and has low smoke requirements."

JASO Explained Part 2: 2-Stroke

JASO Explained PART 2: JASO 2-Stroke Engine Oil Specification The brief history of JASO with regards to 4-stroke requirements was described in JASO Explained: Part 1 and a lot of the same reas…

www.mototribology.com

 

[sunruh]

i owned a brand new 1981 YZ125H
the 1st watercooler
i think i posted a few pics of my paper can castrol 2cycle oil i used it in when i cleaned out mom's house 3 years ago
in '82 the big change was to the linkage of the swingarm to the monoshock .... no more direct
but still had that stupid radiator between the forks...huge issue with the leaking steering stem

the best oil to use in the gearbox is Pennsoil Type F ATF ... maybe costs $2 per quart
i raced with this in the '98yz250 for 24+ harescrambles and enduros and the clutch pack looked new and tranny sparkled

2smoke oil is whatever ... yamalube R is pretty darn good ... yes mc1 was awesome but cannot be found as it was discountinued
you actually make more hp with more oil as it seals the rings better. 32:1 is good
spooge is all about jetting

 

[cknight49090]

the crank capacity is listed as 1.5 liters but on the side of the case says 800cc?

 

[Bonz]

the crank capacity is listed as 1.5 liters but on the side of the case says 800cc?

Not familiar like you guys with two strokes, how is there a crank case capacity since it’s a two-stroke. Or is crank capacity what two stroke guys call their transmission capacity?

 

[cknight49090]

gear box

 

[Alain2]

800cc. Not sure where you got 1.5l from.

 

[Bonz]

Maybe one of those deals where the printed literature is incorrect.

 

[cknight49090]

Just online

 

[ZeeOSix]

the crank capacity is listed as 1.5 liters but on the side of the case says 800cc?

Is there a dipstick to check the oil level?

 

[cknight49090]

no dipstick but i will use 800cc or maybe a little under

 

[Surestick]

So i picked up a YZ250 on trade it has less than an hour on a .60 over wiseco piston and rings at least thats what i was told but i believe the guy.He said he mixed the oil 32.1 and its a bear to start to say the least.I believe a lot of this is due to the oil which is just cheap 2 stroke oil.When i was growing up we always used Bel Ray MC1+ as it smoked less and we used to run it at 50.1 or even 60.1.What is a good oil i can use thats readily available and what ratio should i use?And what should i use in the gearbox and how much if anyone knows? Thanks !

I'd guess your starting issues are down to one of three things:
- Poor compression (easy enough to check).
- Carburation issues (have fun).
- Weak spark at low rpm.
I don't think a 32:1 oil mix is going to cause starting issues.
How does the plug look? Does a clean plug improve starting?

As far as changing mixture ratios goes remember that less oil = more fuel = richer mixture = fouled plugs.

As far as gearbox oil goes what does the manual recommend? I don't imagine motorcycle gearbox design has changed much in dirt bikes. My '99 YZ125 recommends 75w90 gear oil but the intertubes seems to favour Type F ATF which has been working well for me.

 

[cknight49090]

i got it running it idles very high and the slide wasnt open. gas was pouring out of the vents i rode it for a couple mins and it was a handful.The trans didnt seem to be shifting correctly i drained the gear box and about 3 or 4 ozs of what look liked gear oil came out i put in the bottle of castrol.I guess i will order a carb kit it had power even at 1/3 throttle thats about what it was idling at.Been trying to find a carb kit online and go from there.

 

[Alain2]

You should fully disassemble the carburetor, including the nozzle. You should clean everything, especially the air jet (the air jet may be hidden behind a brass ball depending of your carb model). Inspect your carburetor before thinking about buying new brass. If you need new parts, only buy original Mikuni, copies and no name kits are only going to give you trouble.