Jet Sizes

[Guest]

Aloha gents,

I've installed a stage tres dynojet kit on the horse but I'm curious if I should insert the 155 or 160 main jet? Dynojet states that for a stock exhaust with pod filters 155 should be okay but with any aftermarket headers or slip on, you should use the 160. Anyone had any issues with this dilemma?

[5azzmonkey]

Aloha gents,

I've installed a stage tres dynojet kit on the horse but I'm curious if I should insert the 155 or 160 main jet? Dynojet states that for a stock exhaust with pod filters 155 should be okay but with any aftermarket headers or slip on, you should use the 160. Anyone had any issues with this dilemma?

I'm sure before anybody will be able to help you they will want to know what is your exact setup ? (pods, aftermarket exhaust, stock exhaust ... etc)

-Dave

[Staninator]

I'm sure before anybody will be able to help you they will want to know what is your exact setup ? (pods, aftermarket exhaust, stock exhaust ... etc)

-Dave

I have pod filters along with straight pipe exhaust from yeah pair of cylinders.

[Agemax]

I have pod filters along with straight pipe exhaust from yeah pair of cylinders.

why is it a dilemma? go with what DJ says and see how it runs.

you have pods and an aftermarket exhaust, so go with the larger mains, as they instruct.

[Staninator]

Alright thanks guys! I was just double checking because I was having idle issues initially. I don't want the air to fuel ratio to be crazy.

[Agemax]

even if DJ recommend those jets it doesn't mean that they will be perfect for your application. you may still have to fiddle about with jet sizes or needle positions to get everything right, but you will be in the ball park to start with, saves having to guess a starting point and spend a fortune on jets.

[gsrick]

I have pod filters along with straight pipe exhaust from yeah pair of cylinders.

A picture is worth a thousand words.
Is this like what you are talking about by straight pipes?

[Staninator]

A picture is worth a thousand words.
Is this like what you are talking about by straight pipes?

Yes! That is a beautiful bike there. Rat bobbers are my style.

[Staninator]

I'll try the 160s first then I'll drop down to the 155s if I lose power. Before I would idle very high (3k) and it wouldn't start up if left sitting for long.

[Steve]

I'll try the 160s first then I'll drop down to the 155s if I lose power. Before I would idle very high (3k) and it wouldn't start up if left sitting for long.

First of all, main jets have NOTHING to do with starting and idling.

Second, you don't necessarily change jets "because you lose power".
Do measured runs at specific throttle openings (RPM doesn't matter all that much, it's throttle opening), then inspect your plugs.
THEY are the ones that will be the authority on whether you need to re-jet.

.