What size injectors should i use???????????
I've got an 88 with a 103 stroker crank, 106 big bore kit, 10.66 compression, Dave Mackie heads, 584 rocket cams. in upgrading to a HPI 51mm throttle body and unsure what size injectors i should run?.......the bike made 110 h.p. with the stock 44mm throttle body and stock injectors.

 

Give year and model. Different model injectors for different bike models.

 

04 fatboy

 

Interesting post. I do a lot of rebuilds and don't just throw new parts just to be doing it. So I always clean injections, do a leak down and spray. I figured there better then some aftermarket from AutoZone. And even there are pretty expensive.

It appears to me no matter the size of engine with in what I have worked on, they all were capable of drowning a engine.

Doesn't the ECM control on and off? They work from idle to WOT.

I do know they are very small however on a Harley.

Welcome from North Beach, FL., USA!

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​​Your all set.... Enjoy the ride! ______________

 

You do need different size injectors. They range by flow rate. My Dyna right now is limited because of my injectors. Basically my motor outruns the amount of flow my injectors can provide thus leading to less hp and torque at WOT

As far as the OP. Call HPI and ask them. They will tell you.

 

4.9-5.5 would be fine.
m

 

I would suggest 5.3 red band injectors from HD.