1984 FXSB with dual plugged OEM heads, S&S 80" jugs, Dyna 2000i ignition, Python Pipes, Hydraulic Lifters, Super E and that's all I know about this engine. I do not know unfortunately the inner products in this engine.

- The timing is set to the very left edge of the window.
- Primary side plugs are NGK ZGR5C.
- Carb Side NGK UR5.
- All plugs gapped .030.
- 2000i set to Curve 3.
- No VOES.

All I know of carb settings at this point is the idle mixture set at 2.5 turns out. I haven't played with it at all yet. Haven't pulled the bowl.

Engine runs great low-mid. Fires up without a fuss cold and hot. Very responsive. However, once I get up towards 3/4-WOT bike feels "fat". No lean bog, no popping, just fat. Lots of vibes and not much GO if I can describe it best. Fuel mileage doesn't seem that good either. Always been like this as I try not to push it, and riding like a "grandpa" the bike performs just fine. However, it is nice to crack the throttle now and then. Clutch seems to be grabbing OK.

I'd ASSUME the main jet is a bit fat. Yes, I need to do a plug chop. I have new plugs on the way.

Here are pics from a bit back when I pulled the plugs for the first time since I bought it. (Short reach plugs are the carb side, orientation is exactly as it would be sitting on bike with the left side plugs in the photo being the front of the motorcycle, yes that rear primary side plug is a bit wet/oily... maybe a leaky valve guide).







I replaced them, just because they obviously had some MILES on them and rode a couple days of regular riding. No WOT plug chops. Bike still seems fat up top with no good PULL.

As for the plugs though what do you think? When the new plugs come in I will gap them all .030 and do a WOT plug chop and post back.

 

the rear plug and what it could be

remove the air filter cover and filter - turn the fuel on - led light the carb inlet well - what your looking for is if the direction of the acc pump squirter stream is totally centered when turning the throttle - seen some spray favoring the rear of the bike even a small amount has an affect on leaning the one and making the other rich

think of it this way - as you are in the throttle the G forces are sending 60 / 40 split of fuel rich to the rear in some cases - we want a 5 percent difference

so the needle is turn able ever so slight you want a front spray pattern - I said slight - if you don't have a geisha fan spray and a line spray you need to clean the tip with a razor blade and compressed air till it becomes a fan - FIRST -- bowl in hand mineral spirts works

 

Will check the spray pattern John.

The photos I posted above I didn't realize was after I replaced the plugs and ran for a couple hundred miles.

Here are pics of that plug when I first pulled it. My gosh it sure seems like some oil tho. The bike was having vibration issues... probably because it wasn't firing on that plug!





I know I'm kinda all over the place here. Bike is running OK now other than the 3/4 to WOT. I need to get back to square one with new plugs and CHOP test. Checking the spray pattern as noted and keeping an eye on that rear plug.

 

valve seal popped off - valve guide is bad - pistons might have scored in the jug as it got way hot or was abused at hi engine speed for miles and miles

 

Damn. I replaced this plug and the others quite awhile ago too. Hell I did a trip from CT to Maine and back.... no oil consumption noticed on the stick. No exhaust smoke. No noise. Should probably do a compression test at a minimum? Before pulling head?

 

Ordered a leak down tester to confirm. In meantime I will pull a compression test.

 

compression wont really tell the story your looking for as the plus are oil wet and that oil will send the compression higher then it actually is


leak down will give a better test

 

Also.....check voltage to coil...weak spark wont help....but thats oil. Check oil returns in lifter blocks too.....found a set last year....guy never could get push rod tubes sealed up. After i bought it and had the china chrome lifter blocks out to clean up.....magic...no oil return holes. Drilled 1/8 holes no leaks nice clean plugs....you never know. Heads come off these farm tractors easy...so not a big deal

 

wanna ride to cheshire you can use my leak down tester...only a few mins to do

 

I understand that with the older ignition systems the plug gap is .028 but with the Dyna 2000i shouldn't that bet set between .035-.040"?

Also why would you have short reach in the front head and long reach in the rear head?