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Bultaco start up
Posted August 06, 2012 - 12:59 PM
Posted August 06, 2012 - 02:37 PM
Edited by YHGEORGE, August 06, 2012 - 02:38 PM.
Posted August 06, 2012 - 04:18 PM
Posted August 06, 2012 - 04:24 PM
I would avoid putting ethanol laced fuel in the fibreglass tank.
Edited by moto vita, August 06, 2012 - 04:25 PM.
Posted August 07, 2012 - 01:04 AM
2 different fluids in bottom end - trans filler is center top, clutch is right top. drains are pretty obvious
i would expect at least the left side seal to be bad. maybe not. both seals are pretty easy to replace, the left one is easier.
clean carb, inspect/clean points.
fluids listed below.
Edited by nyabinghi, August 07, 2012 - 01:05 AM.
Posted August 07, 2012 - 12:07 PM
Second check the carb expecially the bowl the Bing of the Bul looked like this when I opened it:
The left oil gas mixture had devided in a clear liquid smelling very bad and a honey colored residue that was impossible
to get rid beside mechanical. I ended up buying a new one, (not easy to find this type btw.).
Here some of the jets:
Main bearings and con-rod where rough going too, (so they were corroded) :
At the end I had to do a complete rebuild, anyway maybe I just an unlucky person but before you spend endless time
to get the bike running I would advise, to check the bearings, the carb, airfilter too, (the foam of my bike had disintegrated),
and replace the fluids.
Posted August 07, 2012 - 12:20 PM
Edited by YHGEORGE, August 07, 2012 - 12:21 PM.
Posted August 08, 2012 - 12:51 PM
You can use the same fluid for both sections, when using gear oil in both boxes the clutch is a pain, (the clutch has only metal plates!), instead using in both boxes thin ATF then changing gears will not work smooth and as the engine uses still felt seals and has a tiny little open vent hole above the front sprocket the bike will loose oil from the gear box too.
My recommention gearbox oil for the gearbox W75 - 90 and ATF for the clutch, this combination works best.
Gasoline with up to 5% ethanol is no problem for the engine, carb or the gas tank (in own experience).
Edited by P-Schrauber, August 08, 2012 - 02:55 PM.
Posted August 08, 2012 - 11:08 PM
it is a bit different than modern 2 stroke. all metal clutch plates, primary chain, felt seals, etc.. atf leaks out of gear box for sure, and would need changed frequently. best to use heavier oil i.e. (75w+) for gearbox. clutch can use atf, i've had no problem with it, but the primary chain wears the atf pretty quickly. i run 0w-40 in clutch, lasts a lot longer...
No need to use different fluids in the bottom end and a general cleaning of the carb, forks, etc should be understood by anyone. Other than the possibility of an ethanol /gas tank problem there is nothing different than any modern two stroke. Anything that works in a new KTM will be just fine in that old Bul. I used the recommended Bardahl premix in my Alpina and Matador but I'll bet that will be hard to find today.
10% ethanol can and will melt the tank. maybe 5% won't. either way, draining gas out of fiberglass tanks is pretty much the only way to ensure it's not going to melt.
Edited by nyabinghi, August 08, 2012 - 11:09 PM.
Posted August 09, 2012 - 07:48 AM
This may help for U.S. residents -
Posted November 12, 2012 - 11:34 PM
"Fill the Primary side with 300cc of 10SAE oil And fill the Gearbox with 600cc of 90SAE oil."
Re: Bultaco Overhaul by John Larsen, Cycle Guide Sept 69.
Recomended Fuel Super Unleaded.