I'll try 91 octane today for shits...

I am using the 95mm Weisco, Web cam, and stock valves and springs.

renegade1 wrote on 05/31/12 at 08:55:09:


As noted by Paraquat, going with a larger piston/bore size does not require any other changes to the engine.  Changing to a camshaft with more valve lift and duration; opening the exhaust ports; header with larger ID and good flowing muffler; performance designed carb; and such things will complement the effect achieved with a larger piston and higher compression.  Any of the changes, in most any order, will improve the efficiency and power of the engine.  
I consider the basic 3 for efficient power to be carb/cam/exhaust.  They are fairly quick and easy to replace and will transform the character of the engine, and the camshaft is at the heart of the character transformation.
Any of the changes, when combined with others have a synergistic effect on efficient engine performance.  1+1=3 ... 1+1+1=5 ... etc.
This engine is so much fun to play with.  In stock form it is so under powered and responds so well to massaging.

Ever check to see why the DR650 ('90-95 model years) has a stated 45 hp and the LS650 is just 30 ?  It has a 1 mm larger bore and 3.6mm shorter stroke; the valves are the same size; compression is slightly higher; but the camshaft & exhaust ports make the biggest difference.  Valve lift and duration are significantly higher/longer and the head is shaped a little differently with allows for more open ports and exhaust flow.  There is also no outer blocking ring at the exhaust port exit like on the LS650 head.  Bigger hole = more flow.

With a little creative work it is possible to adapt a DR head to the LS engine.   That is my opinion based on direct comparison of the parts in side by side examination and measurements.  That could be a fun experiment.    

some of this talk about octane is interesting... in my OM it says ust gas(no ethenol) and the only think that has no eth. is 94 octane. 87 and 91 "may contain up to 10% eth." should i always he using 94 then?? the previous owner always used 87.

Have you ever cut out the internal pipe from the stock header and ran just that? I haven't measured the diameter, but it sounds like an interesting idea...

I'm thinking about just opening up the inside, making sort of an anti-reversion chamber. I think the stock outer tube is 2" so the bend out of the head change to 1.5", then dump into the 2", then back into the stock inner.... Have any pictures of a 1.5" custom header?

I called up boulevardsuzuki (the place I got the parts from) and they said they haven't shipped my order because they're waiting on one more piece.
No one had any idea I even placed an order. When it comes in though this piston will be available.


--Steve