Help with crank bolt

Hi guys
I have an issue with my mid drive motor..actually the bottom bracket ISIS splines. In order for my outer chain to line up properly with the outer chainring and not fall off from being misaligned, I need to use a small spacer 3~4mm that I put on the BB splines then slide the crank arm on so that the outer chainring sticks out a bit further than normal. I now need an extra long crank bolt to reach the extra distance and make sure that plenty of threads are in contact with the bolt for obvious reasons. Hopefully my description of the problem is understandable.
Any info or recommendations would be appreciated!
I searched a lot online but couldnt find many options

If you have a regular cartridge bottom bracket, it's usually better to pull it out and put a spacer between the drive side of the bottom bracket and the frame... then the crank arm can slide on and seat like it should.

Voltron said:

If you have a regular cartridge bottom bracket, it's usually better to pull it out and put a spacer between the drive side of the bottom bracket and the frame... then the crank arm can slide on and seat like it should.

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Yes but actually i attached the PAS on the left side of the BB so the crank arm has less splines to slide onto but it goes on about 75% of the way..so i need a longer M12x1.0mm bolt. That type of bolt seems hard to find online..there are no local hardware shops around me so i wanna order online

The ISIS splines are tapered slightly so there is an interference fit between the crank arm and the spindle. The bolt is only there to keep the crank seated on the splines and not intended to have high loads on it. Even if you find a suitable length bolt you would not want to use it that way. The proper fit on the splines must be maintained. If you need more space you have to use a longer spindle.

DanGT86 said:

The ISIS splines are tapered slightly so there is an interference fit between the crank arm and the spindle. The bolt is only there to keep the crank seated on the splines and not intended to have high loads on it. Even if you find a suitable length bolt you would not want to use it that way. The proper fit on the splines must be maintained. If you need more space you have to use a longer spindle.

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Thx for the reply
Yes i seen that they are tapered. At the moment i have everything installed and running well so id rather not replace the spindle yet.
Even if the bolt is there to keep it seated..im assuming at least there would be more threads in contact with the spindle and not slip off