Ed, think it over several more times before you do it. What bothers me a bit about it all is we just do not have much oil pressure to start with - 10 psi best case - so the pump really is just moving oil around with enough pressure to push it through the filter and lift it to the head as it leaks out along the way oiling various parts. Need to be really sure the external cooler and its placement doesn't cause any drop in pressure at all as there is none to spare - while the oil coolers that run up the frame are neat looking it seems unlikely it could be done with out a serious drop in pressure due to the height/lift.
As was suggested a power steering cooler mounted roughly inline with the current oil flow shouldn't cause a drop as long as it doesn't introduce any restriction.

Another thought is if the purpose is to cool the engine it seems to me a positive air flow through the engine would help in this regard. These being single cylinder engines allows this to happen fairly easy as each time the piston goes down 652cc's worth of air is displaced with no where to go except out through the head breather tube and as the piston goes up it sucks back in generally the same air so this stock design simply moves the same air back and forth through the head breather tube and air box. with a filtered air intake say at the filler cap and an air exhaust at the current head breather tube - directional check valves like pcv's or perhaps reed valves should do the trick.    

Keeping dang boats together will take all of ones time I've noted over the years

jhb478 wrote on 12/31/69 at 16:00:07:


I have seen where several folks have mentioned changing the final drive ratio by putting a smaller belt-drive pulley on the rear wheel...but it occurs to me that there might be an easier way to go about getting a different final drive ratio.

Has anyone considered putting a smaller primary-drive sprocket on the input side of the transmission? Suzuki makes a boatload of bike transmissions...I bet there's a factory bolt-on in the neighborhood of 20% smaller. Working out the right length of drive chain might be tricky, but if it worked, it would all fit under the stock primary drive cover.

Of course I'm assuming that the primary drive is a chain and not a belt...I'm a newbie in every respect, so I don't know for sure.

A 20% smaller input sprocket on the tranny would yield 20% more top end, assuming the bike has enough power to top out the rev range. That would turn an 85 mph bike into a 102 mph bike with more liesurely acceleration. Fuel economy at highway speed should be unchanged, or perhaps a smidge better.

I am very strongly considdering going to a chain drive, and getting a couple of different tooth rear sprockets.  midrange, HP, and tq...

klx650sm2002 wrote on 12/31/69 at 16:00:09:



'bout time!

Enfield_fan wrote on 09/21/06 at 09:59:05:

You mean the primary gear and clutch gear?
no chain inside.
the '86 is supposed to have a different gear ratio then everything else.
I have an '88, and it's the same as a '96.  Although I haven't counted them.  It's been said that on a early model, the primary gear can be taken off before removing the clutch.
If that's what you wanta do, then there you go, get a primary gear and clutch basket off a '86.

justin_o_guy2 wrote on 02/15/09 at 15:11:46:


so true and even the size of the chain makes a difference. Most streetbikes come with a 525(size) or 530 chain. Just swapping to a smaller chain (520 conversion) makes a huge difference...