My LeMans IV restoration/engine build

[pressureangle]

If you're jetting a LM1000 with 40 phm's, this will save you lots of time and work much better than any recipe with a K19 needle.

K4 needle, bottom clip
128 mains
68 idle
50/3 slide
265 atomizers

adjust mains + or - 1 size and needle up or down 1 position depending on your bike and altitude. midrange throttle will be night and day better. I post this recipe every few years.


And that huge lean section on your dyno result is a dynamic effect from vacuum drop when whacking open those huge carbs...dont get distracted by that- just look at steady state effects you can jack acc pumps way up to try to compensate but a little throttle control in real world riding is the best solution.

May be headed back to 265 atomizers... here's what is in it now, driving better than ever.
After a 400 mile weekend and a 100 mile weekend, plug reviews and very good riding weather-

138 Mains
268 atomizers
50/3 slides
k19 needle full lean (thought I had k4 but have two sets of k19s)
45 pilots
closed pumps

Plugs are white inside, dark tips; just a touch of rich burble at cracked throttle cruise. Idle screws only about 1/4 turn out. Drives awesome, got 50+ mpg with fast x-way and 45-65mph cruising. That's about 8mpg better than average when it was stock.

I've installed 42 pilots, and on the stand now it wants 1-1/2 turns out at idle and response sounds ok; we'll see after a test ride how it drives. Still have the pumps off.

I'm probably going to ride back up to Daytona next weekend, we'll see how it goes.

[rocker59]

moved to builds.

[perter]

May be headed back to 265 atomizers... here's what is in it now, driving better than ever.
After a 400 mile weekend and a 100 mile weekend, plug reviews and very good riding weather-

138 Mains
268 atomizers
50/3 slides
k19 needle full lean (thought I had k4 but have two sets of k19s)
45 pilots
closed pumps

Plugs are white inside, dark tips; just a touch of rich burble at cracked throttle cruise. Idle screws only about 1/4 turn out. Drives awesome, got 50+ mpg with fast x-way and 45-65mph cruising. That's about 8mpg better than average when it was stock.

I've installed 42 pilots, and on the stand now it wants 1-1/2 turns out at idle and response sounds ok; we'll see after a test ride how it drives. Still have the pumps off.

I'm probably going to ride back up to Daytona next weekend, we'll see how it goes.

Nice post - your choice of pilot jet is really surprising to me.
I run a SP1000 with 36mm and I have issues with the engine starving and popping lean with 60pilots and screw 3½ turn out.
I'm currently trying 65 out and have a set of 70 pilots on order. Other jets are 140main, K18 needle 2nd clip and AR268 atomizers.

The only explanation I can come up with is your engine sucks way better than mine during idle?

[pressureangle]

Nice post - your choice of pilot jet is really surprising to me.
I run a SP1000 with 36mm and I have issues with the engine starving and popping lean with 60pilots and screw 3� turn out.
I'm currently trying 65 out and have a set of 70 pilots on order. Other jets are 140main, K18 needle 2nd clip and AR268 atomizers.

The only explanation I can come up with is your engine sucks way better than mine during idle?

Yes, I'm certain it's a function of the Web 86b camshaft, a little more compression, and an outstanding port/valve job by RHC engineering.

After a couple thousand miles, I'm certain the pilot needs to be one size smaller, probably the needle jet as well. I need to find a set of stock slides, which are leaner, to test. Even though I'm getting 50mpg highway, the plugs are still darker than they should be and it mutters a little at 2200-3000 at slower speeds. Still haven't got back to the dyno for the mains, either, and have not changed the ignition timing from stock.

[pressureangle]

Well, getting back at it.

My wife passed away, as explanation. Thank you for your concern in advance.

So where this was left, the tuning phase revealed a couple things; though the valve guides are in good shape, there is so much more manifold vacuum that too much oil was being drawn into the engine (probably coupled with the high-volume oil pump sending more upstairs as well) and on the dyno, the valve train lost control around 7000 RPM, even with the R&D titanium retainer spring set. So I've fitted valve seals, which required shortening the already short guides, but only .050". I used Chrysler seals, easy to buy the cutter and cheap seals. I fitted PAC single beehive valve springs, sized for Ford Modular engines under PAC titanium retainers, considerably lightening the spring assembly as well. Spring pressure installed is 110# seat and about 275# open. That's a lot, but a couple thousand miles on the R&D set shows a perfect pattern and zero concern between the Web cam and Ford lifters. I gave it new valves as well, considering the age and abuse the stockers had on them. As long as the cam doesn't break in half it should be great, and get RPM up to 8000 with a safety cushion and take full advantage of the cam's specs.
Back to tuning.

[Frenchfrog]

sorry to read your loss.