Q. Clutch make a noise when pulling away.

A. Not an uncommon thing, make sure you only run mineral oil, some will bed in and stop, you can fit better plates EBC, key is no to over rev when pulling off.

Q. Engine has Seized up piston

A. Low oil most common, running weak, "not running a heat spacer between the carb and engine can result in them running weak, mainly on smaller engines. Incorrect gearing and the engine has cooked through over reving. Too restricted exhaust.

Seized in gudgion pin is a first sign of low oil.

Q. Valve heads failing off.

Valve heads don’t just drop off they have suffered some form of trauma .

A.Common causes

  1. Incorrect valve timing, especially with high compression pistons, you will need to dial in the cam so the LCA is equal. Timing marks are not 100%
  2. 2 Incorrect piston to valve clearance 2mm is the minimum at 12 degrees before and after TDC on rocking stroke.
  3. Cam timing float, where there is an issue with the cam chain tensionerand it’s allowing the timing to float/move.
  4. Tight spots in the cam chain can cause the chain to jump teeth on the crank sprocket.
  5. Tappet adjuster nut coming loose, and yes the actually in most cases they wind them self’s in and can under high revs go in that fast so the valve makes contact with the piston.
  6. Something has passed through the engine i.e stone, broken needle etc.
  7. Too higher PSI valve springs and has over stressed the valve.
  8. Exhaust valve clean break on join is normally a sign of over reving and it’s been clipping the piston just enough to fracture the joint

High comp slipper pistons.

Q. Piston has seized up on both sides of skirt like a H shape in a short time.

A. This is a sign of a cold seized, where the piston has expanded faster than the cylinder has.

Common cause not run in enough or not warmed up enough while stationary to gain heat in the cylinder. Other cause is running too weak by jetting or manifold leak.

Big end failures

Common causes are below

Run low on oil “This is the most common issue for failures”

Using synthetic oils and running lower than 10/40W “engines have to run mineral oil only”

Not cleaning out the oil spinner/filter regularly “Too much build up in the spinner or clutch will end up falling off the walls and ends up going directly through the big end”

Prolonged over reving by no having the correct gearing can evacuate the sump putting most of the oil in the top end.

Z190 starter chain

Snapping starter chains can be caused by:

1 The idle is set to high and it bounces back on compression when you turn off the engine, especially with 212 engines.

2 Left to long, we recommend checking the chain tension every 800 to 1000 miles

3 staling the engine can really put stress on the chain too. Make sure you don’t stall!

Gear box

Q.I have just fitted a new set of gear clusters  and did a short road test and it locked up the gear box. Stripped it down and its stripped 2nd gear completely and some of the others.

A.This is we have see a lot of times now, it’s due to leaving out the shift drum thrust washer and bolt that controls the amount of end float of the shift drum, if its allowed to float more it will they select half gears causing it to jam and crash the gear box.

Gear box

Q. My gearbox has locked up while riding.

A. This is normally caused by clutch less gear changes or incorrectly adjusted clutch and not being positive while selecting gears.  Will cause excessive ware to the selector forks/gates that it can allow the gears to catch and jam.


Q Swinging arm brake anchor on monkey swing arm breaking off.

A. Normally caused by axle not being tightened enough and the entire load is on the anchor. Also the swinging arms are designed for 8” wheels, so if you run bigger wheels the leverage is greater and can result in it sheering off the anchor.

Swinging arms

Rubber bush “silent block” swinging arms must not be over tightened or its will result in ripping out the steel centre sleeve. Some frame are made narrower so you will need to shim out with a washer to prevent it pulling in a ripping the rubber.

Swinging arm bolt should be used with a new lock nut and only tightened to support, this allows the steel sleeve to move when the rubber has reached its full stretch

With rubber swinging arm bushes you only want to tighten the pivot bolt enough so the centre of the bush can still rotate on full swing.

Don’t run the chain too tight or it will rip out the left side bush.

Bigger CC high torque engine will hammer the bushes


Starter chain:

Q. I have just fitted a new starter chain and it has snapped?

A. Common issue is that the small drive sprocket has been fitted on the wrong way round, this will derail the chain over the sprocket and snap it. Or some cases the starter gear has picked up on the alloy back plate, causing drag.

Have also see the starter clutch not allowing the starter gear to free wheel and the engine is dragging the starter around !

Check the starter switch is disconnecting and not running the starter motor constantly.

Check the decompressor is working some of the Z190 engine 2020 are faulty.





Q. Bought new 2 part split rims and the have distorted when inflated.

A. Never inflate wheels until the hub is bolted in especially on the DAX ST type hubs, max inflation is 30 psi, any more you will start to misshape the rims.



Q. Rubber bush bearings ripped out in a short time.

A. If the swinging arm pivot bolt is to tight it won’t allow the centre of the bush to rotate n the axle and will result in the bush failing.


Q. My reg/rec has failed after i replaced it.

A. Its likley its the wrong type of reg/rec for the gen, there are 3 types, Split Phase, Single Phase, 3 Phase, some even have there own type of reg/rec between each type. Running the wroung reg/rec will result in them burning out and as they are on a constant live circuit and not on the key switch can burn out the internals and catch fire, so make sure you have the correct charge rate across the battery and bulbs are not blowing on split phase circuits.


3 phase reg/rec’s must have the black wire connected to a 12V switch feed + otherwise it will over charge the battery with voltage as high as 25V D/C and will end up boiling the battery.

You also need to be sure you have the heavy negative cable connected to the engine block otherwise it can pull current vial the reg/rec and melt the solder on the circuit board and wires can just fall out the unit.


Q . I’ve just fitted a new stator and flywheel, I now have no spark or charging issues.

A. When you tightened the flywheel did you stick somthing through the hole to tighten the flywheel nut?


You more than likely to have damage the ignition coils or charge coils then.

Q. My flywheel has come off

A. Incorrect flywheel torque, and not thread locked

Q. Fitted an E start engine, went to start it and could smell burning and battery was boiling?

A.You have more than likley not fitted the heavy earth cable from the neg of battery to the engine block and it has use the stator as the earth and it has melted the Neg cable from reg/reg into the + cable. can melt the 3 yellows too.