I'm thinking of selling my MK1 square four . It is an import from singapore so age related plate and registered in my name I have masses of history from its past . It was rebuilt in 2019 and has only been ridden 70 miles so still needs running in . I just have too many bikes and not enough time to r...

Try these ive never used them myself but have spoken with them and got good advice which fixed mine . https://www.tjmagnetos.co.uk/services

When i first did the gearbox refit on my square four the gears were difficult to non existent . Until I found out that the neutral referred to whilst refitting the outer casing is infact a false neutral between second and third . Refitted in that position and everything worked perfect . So find that...

Paul_Linden wrote:

Should look very similar to this one .

Guy, I thought that picture looked familiar - it’s one of my bike.

I think you sent it to me when you were educating me about the spray bar . Hope you dont mind .

Should look very similar to this one .

personally I would make a stepped key , but I do have a milling machine , that way it would fit both the crank and the gear .

Had this problem when I built my square four box up . The neutral used when you install the foot change assembly isnt the neutral between 1st and second its the false neutral between 2nd and third . The dots need to align when the gearbox is in this false neutral . Dont know if thats how you did it ...

Thanks for the photos paul . looks as though its an engine out fix . Going to get some miles on it first .

Thanks for that I understand it a bit better now . is the feed taken from the return line .

Does anyone have any information on the square four spray bar modification . Pictures would be good .