1974 FLH questions

[Wildman510]

I new to the forum.  This summer I finally got my hands on my grandfathers 74 FLH that he bought new.  Sadly when I got it from another family member it had been neglected for years.  Myself have grown up with jap bikes so I have no idea how much power this thing should have.  Its got an S&S 84" stroker,  S&S super E,  Dyna single fire ignition,  Vthunder cam (no idea which one),  and final drive is 24 tooth front and 49 rear.

My question is im pretty sure i have it tuned the best i can.  The rebuild is fresh.  On the flat 1st through 3rd it will out run evo's and my dads twin cam cant pull on it.  Fourth gear seems to top out at 85mph.  On hill going up the mountains it will only run 63 to 65mph in 4th.  Does this seem right?  I thought fourth should pull a bit better.  Ive been putting this bike back to stock configuration so its wearing bags and the big windshield.  Ive been working on jap bikes since i was a kid and am the one people call for carb issues, timing and rebuilds.  Am i expecting to much from this bike?  Like i said i have no experience on how it should run.

[guppymech]

Nice looking bike, your Grandpa took great care of it!  What jets are in the carb? Have you checked the petcock screen? 4th gear pulls need unrestricted fuel flow.  Check out this link to the Installation/Tuning Manual for the Super E, note jetting chart on page 14.
https://www.sscycle.com/docs/default-source/instruction-sheets/510-0251_super_eg_series_shorty_carbs.pdf?sfvrsn=2

I don't know about top speed, maybe 95-100, my stock 80" FXE will easily top 100 but it's not pushing a fairing and 700 lbs.

[Ohio HD]

84" Shovels in a "standard" S&S configuration aren't super power houses. They have more low and mid torque, and depending on the cam used, may have timing for the lower RPM's. That being said, top speed should be "about" 100 mph depends on state of tune, jetting, weight of rider, etc.

On an uphill in the mountains, downshift. Higher elevations will reduce the effective compression ratio, and lean out the carburation.

[Wildman510]

I have the super e manual.  Tried a 72 main pulled the hill worse.  Went to a 70 pulled 63mph uphill in 4th.  68 main it was starving on the hill could only do 50 something.  70 is in it now.  Float height correct.  Has pingle petcock with no inline filter.  Tank is clean.  The pingle sure dumps some fuel.   This hill I use for tuning is pretty steep.  The bike didn't look like that when I got it.  Ive replaced just about every piece of chrome.  The bags are new cause I wont mention who rattle canned the old ones black.

[Wildman510]

Im 240lbs.  My dad used to own this bike after my grandfathers health went south.  He put the stroker in and cam but didn't ride it much.  Hes ridden since ive been working on it and said its never ran this good.  Im the 4th family member to own it.  Just had the topend off cause a base gasket was leaking so I put new rings in while I was in there and freshened up the valves.  Timed with a timing light.  Original sprockets were 23 front and 51 rear.  I had speedhut build me a speedometer that looks close to original but is electronic so I could correct the speed.

[JW113]

I think you're on the right path. Assuming your primary is 24/37, with 24/49 on the final drive, the overall is 3.15:1. Although that is not horribly tall, I think you'll find it will pull speed better by dropping the rear drive ratio. Maybe try a 51T rear sprocket and see if that helps a little?

-JW

[guppymech]

Between 3k to 3.5k rpm on the Super E both the intermediate jet and main jet supply fuel and the mixture goes very rich.  The rpm that the main jet starts supplying fuel can be adjusted by changing the main jet air bleed size.  Bill Rook covers the effect very well in his book "How to build a Harley Davidson torque monster".  Below is a link to the pertinent pages, I hope the link works.



the shorter link  ......

[Ohio HD]

Find a newest CV carb and but that on the bike. It'll handle the elevation changes better than the S&S will.

[Wildman510]

Guppymech that's some good info in that book.  Im very positive I have the carb set up properly.  The 70 main I used with the carb in stock config.  I recently did the thunder jet mod.  My super e is an old one and didn't have the adjustable air bleed.  It does now.  I have days in tuning the carb.  The carb with the thunderjet and adjustable air bleed mod did wonders for allowing me to clean up the midrange throttle response.  Went from soggy to nice and crisp.  Plug burn at various rpms is very good.  On the big hills I can accept that 4th is probably to much gear with the sprocket change.  Shifting to 4th on the flat around 55mph I can roll on the throttle and the bike accelerates pretty good all the way up to 80 then start to crawl it may actually do more then 85mph might just need a longer straight away.  Im starting to lean towards a maybe a different cam or this is all shes got pushing 990lbs combined weight down the road pushing that big sail of a windshield im sure doesn't help.  I changed the sprockets cause stock it would cruise nicely at 55mph and anything faster it would vibrate so much it would make my feet numb.  No I can cruise at 70 no problem.  Im just trying to make it the best I can.  I don't plan on running her hard when im finally finished.  It will be my weekend bike.  Hoping to find a stock buddy seat.  Todays project is to mount the new footpeg brackets I made.  Originals were to far forward and low for my wife.  I was thinking of trying an Andrews #1 cam.

[Hillside Motorcycle]

I'd go to a 23/51 gearing for starters.(make sure the comp sprocket is OE gearing also)
100 mph should not be a problem.

[guppymech]

Wildman, glad you liked the book excerpt, I have a copy and find it chocked full of good info.  Do you know what compression your bike has?  The Andrews #1 with the early closing intake valve is for low compression (7.4:1) engines and may give too much dynamic compression if used in a engine with higher compression.  Maybe a Andrews J cam would be better although I have no experience with it, S&S also makes a reproduction H cam.

[Wildman510]

New stock jugs stock bore.  Stock compression pistons from S&S.  With the stroker S&S says 8.4 to 1.  Both cyclinder checked when how I get right around 150psi.

[MikeL]

My 1980 shovel went to a 48 tooth rear sprocket and a 23 front. It can go well over 100mpg. 9.0to1 pistons, BH cam, street port on the heads, dyna s single fire, cv carb.
I would check your ignition flyweights they may be stuck.


                                                                                                     MIKE

[mplecha]

How did you mount the speedometer in the dash bezel? I've thought about having speed hut build one for me, too, but I wasn't sure how to keep it in place.

Im 240lbs.  My dad used to own this bike after my grandfathers health went south.  He put the stroker in and cam but didn't ride it much.  Hes ridden since ive been working on it and said its never ran this good.  Im the 4th family member to own it.  Just had the topend off cause a base gasket was leaking so I put new rings in while I was in there and freshened up the valves.  Timed with a timing light.  Original sprockets were 23 front and 51 rear.  I had speedhut build me a speedometer that looks close to original but is electronic so I could correct the speed.

[Wildman510]

Mplecha you know the rubber around your stock speedo.  The Speedhut one comes with a plastic lock ring.  I glued the plastic ring in the rubber after I mock fitted everything.  Once the rubber is glued to the locking ring it wont pull through the dash and actually fits snug.  Once the dash is on the bike the plate that holds your indicators and original speedo keep just enough upward tension on the original rubber.  Ive had it on there all year and doesn't move.  I used a good glue that's used to glue rubber belting together.  I also found a large thin o ring and pushed it in around the speedo from the top with a tooth pic.  This keeps it nice and centered.  I can take pictures if you want I currently have the dash off.  Sppedhut sells extra rings and the rubber that covered the original speedo can be found online if it ever needed replaced.

[Wildman510]

I believe I found whats wrong with the bike.  Found out this morning that the V thunder cam was recommended and installed when this bike was running 9.5:1 compression.  Was told it really screamed.  Stock jugs were bought and stock compression pistons were put back in somewhere early 2000's but never ran.  So im thinking the cam is to much for the 8.4:1 its currently at.  Anyone have a good suggestion for a cam?  I would like to maintain the hydraulics.

[Hillside Motorcycle]

Over-gearing a maginally powered bike will in fact, slow it down.
In even later years,
why did HD have 2 teeth less on an 883 trans sprocket, vs a 1200?

[wfolarry]

Along with the lower compression that exhaust ain't helping.

[Hogman]

Along with the lower compression that exhaust ain't helping.

Sort of (Hopefully.....) a Quick Question for You Larry. Are You Saying that, Because You Think His Ex. is Restrictive, or, the Dual Mufflers, or??? Just Curious as to Why You Bring that up. I Know the Hot Rod Folks Prefer the 2 in to 1 & all that, but IF he's Just Looking for a Weekend Highway Type Cruiser, I Would Have to Totally ASS U ME those Would do Ok for him Riding it That way. I Read SOMEWHERE on his Posts, he was NOT Going to Ride it Real Hard once he Finished it, So??? Honestly Just Curious as to Why You say the Ex. is Not Helping, That's All. NOT Bitching one way or the Other Sir.
THANKS in Advance for Your Reply.



ME

[Burnout]

Those factory 2:2 exhausts are an abomination and fart in the face of any kind of tuning.

That exhaust design ruins the volumetric efficiency of both the front and rear cylinder each respectively at different RPMs.

That exhaust design will flatten the personality right out of any camshaft installed.

This is not so much from a performance perspective, it is efficiency not hot rodding or hard assing.
It's about having to downshift for a hill or to pass.
It's about the ability to take off from a light and pull away smoothly without reving up and slipping the clutch.
It's about a smoother idle and part throttle response, heck it even starts better!
It's about a motor that wants to run and doesn't have to be coaxed into moving or flogged to move faster.
It's about both cylinders working together, instead of fighting for breath.

I can guarantee that if you try a good 2:1 pipe you will marvel at the difference, and wonder why the MoCo ever installed those duals as OEM equipment.
Even a proper 2:2 setup will run way better than the FLH/T "dual" exhaust. 2:2 with Equal length pipes and a balance tube work almost as good as a 2:1.
You can feel the difference taking off from a light normally, you can feel it when putting along at 35mph in 3rd gear.

Note: Thunder Header makes a false pipe for the left side for those who must have the dual exhaust "look"

[Wildman510]

Info on exhaust and gearing all good info.  I actually tore the topend down again Friday and started checking some things.  Ive attached a picture of the main culprit on The power being low.  Piston on the left is what was in the bike.  Right is what was in the bike some time in the 90's.  It definetly has the S&S 84" stroker.  This piston on the left according to part numbers and from S&S is the LC stroker pistons 7.3-1.  The right piston is the Stroker pistons HC and according to S&S is about 8.4-1.  So it this bikes ben running a lot lower compression ratio then what everyone has thought.  I have another set of jugs and HC pistons.  Guess whats going back in.  8.4-1

[Hillside Motorcycle]

An 84" Shovel should roll down the road very nicely, set up correctly.

[Wildman510]

Update.  Rebuilt the motor with S&S stroker pistons 8.4:1 pistons.  Had to up the pilot jet, main jet and thunder jet.  Pulls all the way to 100mph now.  Will go faster but im not into beating my bikes.  Not afraid to get on the highway now.

[Wildman510]

Also added an ultima ignition and voes.  Cylinders were bored .020 over and the cylinders were shaved due to a raised oil passage.  Voes is set a 6 inches of vacuum.  Havent been able to make it ping.  Warmer weather will tell if farther tuning is needed.

[76shuvlinoff]

   Enjoy!