Jump to content

A Jetting Debate?


Mrdrink

Recommended Posts

Recently rejetted a set of steely carbs and speaking to someone who knows his stuff we have put the same size jet across all 4 cylinders.

I jetted my Flatslides the same as this before.

I notice that everyone else... inc dyno guys, the OEM put a size larger in the middle.

Ive had this discussion many times with the engine guy and he insists its a waste of time and i have the proof that using the same jet works.

His argument is that he has had IR temp readers on engines and has found no difference in temps on the inner cylinders. Also on alot of engines the coolant is fed into the inner cylinders first from the rad.

I have no doubt that using all 4 the same size will work perfectly fine and im not gonna be changing it but what were other peoples experiences of this?

Link to comment
Share on other sites

big H have got thousands of bikes to manage and in all different areas of the world.

Playing it safe is the crack here..

Same blags on the NC30 JDM - smaller front jets adn larger rears - as they run hotter? UK bikes different, NC35 different (same sizes) - same motor...

So, it is something of nothing!

Link to comment
Share on other sites

FZR's use larger jets on the middles, not sure about my BIM it has a jet kit. Makes you wonder why the factories don't just raise the needles though.

If it works then it's ok

It might be the combustion chamber is hotter and can make use of the extra mixture, so it might not be to cool the middle cylinders as such

Link to comment
Share on other sites

I wondered if anyone had any proof or credible reason why they did this. The combustion chamber one is a thought i hadnt heard of.

All i seem to hear about it is guess work.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...