Popping From Exhaust.HELP

[Posidus]

I just got my trinity full exhaust system. There instructions say if you are installing full pipe and running with airbox lid off; put a 185 main jet in turn air/fuel screw 2.5 turns and put the clip on the needle to spot 4. I did all this and it seems to run fine until i let of the throttle and than it pops everytime. Do i need a bigger jet, anyone have this problem or running a trinity system?

[MAD450r]

My local mechanic just started mine up and adjusted the fuel air a bit more not sure exactly where he put it too but it stopped popping when my filter is clean. If my filter gets pretty dirty it starts to do it again a little, not much.

Hope that helps

[lafinrat]

Check for an exhaust leak at the head.

Put on a leather glove, hold the RPM steady off idle and put your gloved hand over the pipe, you should be able to hear the leak if there is one.

I would also recommend a 52 pilot.

What elevation are you at? That will affect your main jet and needle requirements.

[nowukno]

Did you replace the copper crush gasket were the head pipe connects to the motor?

[400exrider707]

First of all make sure you did put a new copper gasket in, check to make sure its tight, then play with the mixture screw. It only pops on deceleration correct? That would be lean condition on mixture screw.

[lafinrat]

Closed throttle full delivery is most greatly affected by the PILOT. Take it from someone who worked with this carb along side Tomoya at Keihin.

[400exrider707]

Originally posted by lafinrat
Closed throttle full delivery is most greatly affected by the PILOT. Take it from someone who worked with this carb along side Tomoya at Keihin.

You should be able to get rid of the popping with the mixture screw adjustment. Changing the pilot is too drastic of a change. One pilot jet size is similar to 3 or more turns on the screw is it not.

[lafinrat]

Every 450R I've seen with the air box lid off and pipe needs a bigger pilot. 50-52 is about right for gasoline. The mixture screw should always be between 1-2 turns. You can go further in either direction with minimal change, yet that is not the correct way to do it.

[R_rocket]

Put in a bigger pilot jet. I agree with lafinrat.

[chad502ex]

two things comes to mind:

1. exhaust header leak- check that the head pipe is securely tightened preferably with a new copper crush exhaust head gasket.

2. lean condition on pilot- on engine decel the pilot circuit takes over when the engine is still signaling the carb; so, if the pilot is too lean she'll pop

[Posidus]

What is the stock pilot? and on this link, which number is the pilot jet. http://www.planethondaracing.com/cgi-bin/hondaparts/results_parts_details?mv_session_id=UDH2Ap2q&mv_pc=163&se=pg_d_id%3d1108%20and%20pg_my_id%3d25

[hsr]

Try high temp silicone on all seams, to try and seal up any possible leaks.

[nathananders]

How tight do you tighten the header to the head? The manual just says tight. I get poping as well on decel. I tightened the nuts at the header to 10ft/lbs. should I just wrench it until its tighter?

[bwamos]

Originally posted by Posidus
What is the stock pilot? and on this link, which number is the pilot jet. http://www.planethondaracing.com/cgi-bin/hondaparts/results_parts_details?mv_session_id=UDH2Ap2q&mv_pc=163&se=pg_d_id%3d1108%20and%20pg_my_id%3d25

It's item 45. Stock is a #48 pilot (slow jet).

[Posidus]

Originally posted by nathananders
How tight do you tighten the header to the head? The manual just says tight. I get poping as well on decel. I tightened the nuts at the header to 10ft/lbs. should I just wrench it until its tighter?

I just got them really tight. you shouldn't need a torque wrench. I think the popping is due to the pilot jet, but i am going to call trinity today when they open. I think i will end up getting pilot jets 50-52 and test it out.

[Posidus]

Originally posted by bwamos
It's item 45. Stock is a #48 pilot (slow jet).

Isn't that the fuel mixture screw that you are suppose to turn 2.5 turns too?

[MR.BIG]

I had the same problem with my 450 before you do anything try adjusting the air screw.

[MAD450r]

As for the pilot jet mine was increased with the hrc jetting. As for what size it is im not sure off hand.

When mine was popping I had my fuel air screw adjusted by a mechanic with my r running and he fixed it that simple.

[400exrider707]

Originally posted by MAD450r
As for the pilot jet mine was increased with the hrc jetting. As for what size it is im not sure off hand.

When mine was popping I had my fuel air screw adjusted by a mechanic with my r running and he fixed it that simple.

Exactly. I thought the rule of thumb was adjust the mixture screw, then if your adjusting more than 3 turns, bump the pilot jet up a size, then adjust more with the screw. 3 turns of mixture screw = 1 pilot jet size!?!? Anyone confirm or deny this?

[Posidus]

http://www.planethondaracing.com/cg...20pg_my_id%3d25 so to this diagrahm, 45 is not the one to adjust 2.5 turns? i should be moving the #46? Also does that mean that the #45 needs to be tightend all the way?

[nathananders]

Its not so easy to adjust on the 06. It has a d shaped head on the screw and you either have to buy the tool (honda wants 109) or take it to the shop. Anyone know where else to buy the tool?

[Posidus]

ok guys, trinity's specs were good, but you need to change out the copper insert spacer between the head and the head pipe. did a wheelie all the way down the street!!!!!

[4ABURN]

Originally posted by 400exrider707
Exactly. I thought the rule of thumb was adjust the mixture screw, then if your adjusting more than 3 turns, bump the pilot jet up a size, then adjust more with the screw. 3 turns of mixture screw = 1 pilot jet size!?!? Anyone confirm or deny this?

YES this is what I have been told also anymore than 3 turns out and that means you need the next size pilot. Thats right.:D :D

[XCRACER26]

Some times it will also start popping if the idle screw is to high. I had it happen on my R before.

[drider]

popping, hmm , your main jet is good, try 3rd clip on your needle. you should be fine.