Husaberg Motorcycle Engine Tuning

This information is generally accepted for all Husaberg motorcycles.

This information is for tuning the engine. To tune using the exhaust and carburetor, please reference the following:

When tuning, it’s important that all standard features are correctly set and the engine is in good maintenance. Along with this section, we recommend the Engine Rebuild sections, etc. to make sure your Husaberg motorcycle is both fast and reliable!

Engine Tuning

Con Rod

380/450 350/400/470 501 01-03 550 01-02 550 03 644 01-02 644 03-05 628 05-
119.0mm 120.0mm 123.0mm 124.0mm 123.0mm 134.0mm 135.0mm 136.2mm
Conrods left to right: up to 2003 OEH Husaberg, JBS Racing 750, 2006+ Husaberg (JBS Racing)
Conrods: Left to Right: up to 2003 OEH Husaberg / JBS Racing 750 / 2006+ Husaberg (JBS Racing)
Conrods: top 2003 Husaberg 650 9mm width 324g 1mm longer, bottom 2001 Husaberg 650 10mm width 336g
Conrods: Top 2003 650 9mm width 324g 1mm longer / Bottom 2001 650 10mm width 336g (Weed)
Conrods: left 2005 Husaberg, right 2004 Husaberg
Conrods: Left 2005 / Right 2004 (Bergoroadracer)
400 big end, changed due to hours but hadn't failed
400 big end, changed due to hours but hadn’t failed

More Rod Lengths – KTM

107.4mm = 450 SX-F c/w 35mm big end, 119mm = 450 SM-R, 121mm rods std sxs 540/ 05. 126mm std rod from stroker crank. 129mm std 525/450 EXC rod c/w 35mm big end. 131mm = Falicon special, 134 mm = Falicon knife edge, 141.5mm = 620LC4 c/w 40mm big end. Big end marked where known. Some information not original.

Alloy Composite Rod

Engine Hardware uses these in his motors, and the typical weight reduction is:

  • Husaberg FE/FS 450… 120.5mm… 354g to 164g
  • Husaberg FE/FS 550…123.3mm… 360g to 192g
  • Husaberg FE/FS 650…135 mm… 370g to 200g

Cost is E600, and for a further E300, they will balance and build your crank for you. Remember it’s important to always have some Swedish heritage in your motorcycle!

Composite Rod (Engine Hardware)
Composite Rod (Engine Hardware)

Crankcase Heights

We can’t confirm exactly but the 501/550 cases are thought to be 9mm taller than the 400/450/470 cases. The 630/650 cases are 29mm taller than the 400 cases.

Piston Heights

The earlier 470/550/650 piston was some 3mm shorter above the L/E pin than today’s pistons from the 450/550/650. (Hribman) The 470 is domed whereas the 550/650 were flat.

This shows the piston well below the surface of the barrel when at TDC.
This shows the piston well below the surface of the barrel when at TDC. (Weed)

Compression

The BV head has an additional 1.8mm of aluminum at the face and a larger machined out combustion chamber meaning the head alone holds another 10cc (27cc to 37cc). This heavily reduces compression if fitting the BV head to the 400. It is a future test that i see how much of this “1.8mm” can be machined away to take the true benefits of the bigger valve heads. Here is a good photo of a 37/32 head with it’s beryllium seats:

37/32 head with beryllium seats
37/32 head with beryllium seats (Lineaweaver)
Wössner vs 2004 650ccm stock piston
Wössner vs 2004 650ccm stock piston (Bergoroadracer)
Wössner vs JE custom piston
Wössner vs JE custom piston (Bergoroadracer)

Thicker Head Gasket – OEM

  • 21 200 319-01 Cylinderhead gasket 400 (thick) -01
  • 21 200 231-01 Cylinderhead gasket 400 -02
  • 21 200 320-01 Cylinderhead gasket 501 (thick) -01
  • 21 200 232-01 Cylinderhead gasket 501 -02
  • 21 200 321-01 Cylinderhead gasket 470/550/650 (thick) -01
  • 21 200 233-01 Cylinderhead gasket 470/550/650 -02

Standard Head Gasket Thickness

  • Always .056″ or 1.4mm
  • Will compress to .050″ or 1.25mm in use

Close Ratio Sixth Gear

These are found in the FC 470 or 550 gear cluster. Instead of a 27/20 sixth gear, it’s 25/21 for a closer top gear. However when running 13/48 or 14/51 final drive, for a nice first gear in the woods; sixth becomes too low in the open so this might be the wrong mod to do! Here are the part numbers:

  • Input Shaft: 240 076-01 (25 teeth)
  • Output Shaft: 240 086-01 (21 teeth)
Lower 6th Gear
Lower 6th Gear (Bergoroadracer)
Lower 6th Gear
Lower 6th Gear (Bergoroadracer)

Table of Gear Teeth on Gearboxes 2001-2008:
All you can do is buy a pair of lower sixth gears

1st 5th 3rd 4th 6th 2nd
14 24 ( 19 23 ) 27 or (25 CR) 17
33 22 26 25 20 or (21 CR) 30

Table of FC Close-Ratio Gearboxes 1997-2000:

1st 5th 3rd 4th 6th 2nd
15 24 ( 20 23 ) 25 18
33 22 25 24 21 38

First is much, much taller. Second is much taller. Third is ever so slightly taller. Fourth is ever so slightly taller. Fifth is exactly the same. Sixth is shorter. All the like-for-like gears are interchangeable. To find out if a gear from elsewhere is the right one you will need to look at the gear that presently holds that position!

Table of Wide-Ratio Gearboxes 1997-2000:
(available on Husaberg FE Enduro motorcycles)

1st 5th 3rd 4th 6th 2nd
13 25 ( 20 23 ) 27 17
34 22 27 24 20 30

First is much lower, but at this point, you should be getting the hang of this!

Coolant

Stiffer spring: 2.0 psi vs OEM 1.4 psi
Stiffer spring: 2.0 psi vs OEM 1.4 psi (Bergoroadracer)

Camshafts

LX1 and LX2 camshaft aid valve gear life, increase power. The “01” cam is fitted on all 400’s as standard and is mild. For real go the rider has to “cog it down one” so the “53” cam (from earlier FC400 and 550/650) is stronger with 1mm more lift and more duration. The engine pulls a gear higher with the ’53’ cam. The ’53’ cam is the same as the ’55’ cam (only found in the 501 engine) but is 5 degrees advanced of ’55’ cam due to cylinder deck height of that engine (Lineaweaver).

The LX2 Lineaweaver cam is better (SOTP) than the ’53’ cam but has the additional benefit of reducing the valve train loading. In tests the bike could be left to lug in a taller gear, was far better in rollon in gears 3-6 especially. Dale’s cams have convex flanks and a sideview of the two cam profiles can leave you in little doubt! Todays new generation OEM cams STILL have concave flanks and have only marginally reduced the acceleration pressure on the cam follower bearings.

Dale Lineaweaver recommends the LX1 cam for engines of around 500cc+. Increased power comes in from 4,500 RPM and due to overlap and gas wavelengths an open exhaust MUST be used.

Lobe centers for cam timing are:

  • ’53’ cam = 112° (Measured with zero lash). From 1mm lift the ’53’ cam’s -inlet valve timing is: Opens 10° BTDC, Closes 54° ABDC. I could not get Dale’s cam timing figures using the 1mm lash but could get them without it perfectly though! so the simple rule is to have both lobes pointing up at 11 and 1 ‘o clock.
  • ’01’ cam = 110°
  • ’55’ cam = 117.5° (Lineaweaver)
  • LRX1 = 284 / .414″ / 106°
  • LRX2 = 272 / .407″ / 107° (Lineaweaver)

OEM camshafts 820.36.010.000 and H-200.342.08 share identical profiles. The later unit is shipped with a matched auto de-comp lever. 1mm lift / 0 Lash / Straight Up

  • Intake Open 19°
  • Intake Close 67.1°
  • Intake CL 114.9°
  • Exhaust Open 68.8°
  • Exhaust Close 17.9°
  • Exhaust CL 115.1°

Tornado Cams To clarify, on cams and their power characteristics. The G1 cam (which I don’t have) is a stage 1 cam for the standard 650 (2002) bike with a race pipe and pumper carb. The G2 is a stage 2 cam for a 650 with a JE or otherwise high comp piston (a must).

The G3 is a very long opening high lift stage 3 cam for a bigger than 650cc berg with all the above also. None of the GW cams will work well in a standard piped Berg (Supermoto Husaberg).

For further information on camshafts:

To Check Valve Timing

Turn the engine to TDC on ignition mark, check both lobes are up symmetrically. Lay a ruler diagonally across the lobes and it should be absolutely parallel to the top face rim of the head. To change the valve timing, you must slot the holes in the cam gear to allow adjustment. It may pay to have the ruler tilting down toward the floor in front of the bike very slightly. This will actually level out as the camchain stretches. If the camchain link isn’t where you want it, turn the engine over 3/4 times until it is. It moves on a bit every time.

Lighter Valves, Springs, Collets, Caps

The factory runs Ti valves as well as Ti collets and alloy or Ti caps (Lineaweaver can supply). Dual straight valve springs are used from a KTM450SX. The weight differences are:

  • INLETS: Steel 35mm = 48G, Ti 37mm = 30G
  • EXHAUSTS: steel 30mm = 42G, Ti 32.5 = 26G

The Dual straight valve springs from the KTM 450SX are no longer available, Member Faust has found the current OEM replacement: KTM full set (4x) ATV DVSK, Part No. 83036028044, $66 USD. Here is more information and photos about these valve springs.

 

Lineaweaver head with titanium valves, retainers, double springs.
Lineaweaver head with titanium valves, retainers, double springs.
Lineaweaver 37/32 stellite hardened top and coated valves.
Lineaweaver 37/32 stellite hardened top and coated valves.
Weight 37mm Inlet and 32,5 Exhaust Titanium Valves 30 and 26 GR
Weight 37mm Inlet and 32,5 Exhaust Titanium Valves 30 and 26 GR

Kibblewhite or Del-West can supply titanium valves (USA). You must use a lash cap and have the valve treated with Casidium lest they last only a few hours. Del-West valves are used by Factory KTM and Husaberg. Said valves feature a steel tip insert, Casidium face and “BIG” price tag. Kibblewhite valves have a Stellite tip. Reducing valve rates via the camshaft will allow 37 mm SS Intakes to see 10,500 RPM with a low pressure dual spring kit. Unless you plan on 10,000 RPM plus and using an OE camshaft Ti is not necessary. (Lineaweaver)

The seat pressure is the same and the peak pressure is 1/3 of OEM. This will increase the rocker arm cam follower bearing and cam lobe life (Lineaweaver). The springs should only be compressed to a certain height, this is known as the ‘Installed/nominal spring height’. The installed height for the kit is 29.65 – 29.9mm. To measure this: fit a valve in the guide, a cap with collets and measure the gap between the spring’s seat and the underside of the spring cap. With the use of the shims and a lathe you will get the correct installed height.

But… The inside of the camcover on the 2001-2003’s need the rotary file putting over a small area because the spring caps touch slightly.

RD racing head: titanium valves, aluminum retainers, double springs. (Bergoroadracer)
RD racing head: titanium valves, aluminum retainers, double springs. (Bergoroadracer)
Rocker cover before rotary
Rocker Cover – before rotary
Rocker cover after rotary
Rocker Cover – after rotary

Cam Timing Adjustment

It’s possible to file the camwheel bolt holes oval. Camchain stretch means that a keen eye must be kept on the valve timing. There is no danger of hitting the piston (with the standard OEM cams)and the engine is still safe when a rebuilt engine is a tooth out either way. I set the cam leaning back slightly so that over the next period the cam timing will be correct with the chain stretch.

KTM Cam Anyone?

Theoretical Redline

Many ask what the redline is on a Husaberg and unfortunately we can’t give a 100% answer! The way to measure is to measure the piston speed in feet per minute. The formula used is:

S x RPM x 0.166 Feet per Minute

The rule is reliability but however, a factory source told Gazza that it’s “4,500 ft per min”.

The general rule is currently 4,500 ft per minute, and it goes up a little each decade. So if we take our engine and stick to that, then you get the following redlines:

  • 60.1mm stroke (400 and 470) = 11,500 RPM
  • 80mm stroke (628 engines) = 8,600 RPM
  • 82mm stroke (650’s from 2001-2004 inclusive) = 8,400 RPM
  • 70mm stroke (550’s) = 9,900 RPM

Shouldered Mains Housing

Ben Ballard (JBS Racing, United Kingdom) has been racing MX sidecars and by machining out the mains and putting a steel shouldered insert in he can control the rigidity and the fit of the bearings. Note that the bearings are fed in from outside the cases and then an internal nut is used to hold them down and in.

Ben Ballard (JBS Racing, United Kingdom) has been racing MX sidecars and by machining out the mains and putting a steel shouldered insert in he can control the rigidity and the fit of the bearings. Note that the bearings are fed in from outside the cases and then an internal nut is used to hold them down and in. Ben Ballard (JBS Racing, United Kingdom) has been racing MX sidecars and by machining out the mains and putting a steel shouldered insert in he can control the rigidity and the fit of the bearings. Note that the bearings are fed in from outside the cases and then an internal nut is used to hold them down and in. Ben Ballard (JBS Racing, United Kingdom) has been racing MX sidecars and by machining out the mains and putting a steel shouldered insert in he can control the rigidity and the fit of the bearings. Note that the bearings are fed in from outside the cases and then an internal nut is used to hold them down and in. Ben Ballard (JBS Racing, United Kingdom) has been racing MX sidecars and by machining out the mains and putting a steel shouldered insert in he can control the rigidity and the fit of the bearings. Note that the bearings are fed in from outside the cases and then an internal nut is used to hold them down and in.

Additional Oil Gallery

Ben Ballard (JBS Racing, United Kingdom) has added an oil gallery that catches oil and drip feeds it to the LHS main bearing. This aids lubrication, draws heat away, makes for less wear and after all that: more reliability!

Ben Ballard (JBS Racing, United Kingdom) has added an oil gallery that catches oil and drip feeds it to the LHS main bearing. This aids lubrication, draws heat away, makes for less wear and after all that: more reliability! Ben Ballard (JBS Racing, United Kingdom) has added an oil gallery that catches oil and drip feeds it to the LHS main bearing. This aids lubrication, draws heat away, makes for less wear and after all that: more reliability!

Ignition Marks on Flywheel

The ignition timing marks are often found to be out by as much as 8 degrees so check this using the ‘dead-stop’ method. Find TDC and mark the flywheel. Adjust the ignition knowing that timing changes x 2 in the unit. Another reference is the Husaberg Troubleshooting section.

Other Ideas

  • When modifying the bore, use a headgasket with a 1mm larger diameter hole than the bore. Cometic (USA) have patterns. (Lineaweaver)
  • Running without the counter-balancer is fine, it vibrates at idle and then disappears at medium revs. However when ‘revving out’ the bike vibrates badly and tires the rider quickly. The conclusion? In for enduro and normal use, out for SM and MX perhaps. There is no power gain anyway unless the crank assembly is rebalanced.
  • The 400 crank should NOT be stroked. (Lineaweaver)

Stroker Cranks

Engine, 670ccm, 85mm stroke
Engine, 670ccm, 85mm stroke (Bergoroadracer)
Crankshaft, 670ccm, 85mm stroke (Bergoroadracer)
Crankshaft, 670ccm, 85mm stroke (Bergoroadracer)
New 2006 Husaberg crank. Note only the 80mm stroke 628cc engine has a bell crank, smaller cc's have circular cranks like pre-2006 650's did. (JBS Racing)
New 2006 Husaberg crank. Note only the 80mm stroke 628cc engine has a bell crank, smaller cc’s have circular cranks like pre-2006 650’s did. (JBS Racing)
2006 Husaberg with 2007 JBS Racing 750cc kit. (JBS Racing)
2006 Husaberg with 2007 JBS Racing 750cc kit. (JBS Racing)

Balancing the Crank Assembly

When removing the counter-balance the crank should be re-balanced to a factor of 70% plus or minus 10% (Lineaweaver) a spacer can be made to replace the bearing or just use the inner race.

Truing and balancing flywheels Truing and balancing flywheels Truing and balancing flywheels

To test home balanced assemblies… the balance factor was 0.75 initially and now it is 0.58, for what it’s worth, will now be moving toward 0.625. They have welded lumps all over their cranks. On reflection, the use of Mallory (a heavy metal) drilled and pressed as core pellets into the crank might have done it? a Mk2 version should follow. But the Husaberg community continues to experiment.

Crankweights cut to 0.91 balance factor
Crankweights cut to 0.91 balance factor
Conrod reciprocating weight 122g
Conrod reciprocating weight 122g
crank with weights (BF 0.91)
crank with weights (BF 0.91)

Husaberg 400/450

Having checked the squish it was an awesome .046″ (400) which is ‘racing stuff’ (.040″ minimum). The valve to piston is over 5mm (the minimum gap would be 1.5mm on both I and E) on both sets of valves which will allow possibly for someone to accidentally get the timing one tooth out or stronger cam. The springs are very powerful but need to be ‘due to the flanks of the cam’ (Lineaweaver) which creates heavy inlet valve ‘tuliping’. Before tuning make sure the cam rollers, the camchain, camwheel, tensioner blade are upgraded and the valves are in good shape. Be sure to reference these Husaberg red alert wear items.

The pairs of Inlet the exhaust valves of the small valve (35/27) head sit 4mm nearer than in the big valve (37/30) head. This makes it very difficult to put the larger exhaust valves (30mm) into the SV head as the seats are nearer to overlapping. This also explains why the heads don’t share the same rockers.

Bigger Valves

The 2002 400 had 35/27s standard, the later 450 now has the-KTM-like 35/30. Lineaweaver sells 28mm exhaust valves but I fitted 29mm exhaust valves and ported to 100% size of valves(cut down 30mm valves from the BV head). This gave a good increase above low revs (say 4,000 RPM). Larger Inlets at this stage didn’t appear to be needed and so with the inlet valve seats ‘3-angle-cut’, the head ported, devcon used to fill it in the ‘anti-chamber’ another increase in power was clearly felt. But the engine had a flat spot, typically at low revs in second gear: this was cured with an open tailpipe for low rev scavenging and cured this completely.
Porting

The inlet port area needs to be as near to the inlet size (35mm) as possible. The 400 is overported around the branch area and copious use of devcon aluminum paste is required along with reprofiling. This gives more bottom end, midrange and stops the hesitancy that the larger exhaust valves had created. This is due to the increased airspeed and stopping low speed back pressure through and up the inlet ports! Just by putting my hand over the tailpipe slightly; the carb slide would rattle!


Husaberg 550/650

Raise the compression on your 650. (Engine Hardware)