More jetting and plumbing Questions CPR

[Rx1M5]

In an effort to only take the carbs off as little as possible I'm looking for the some input on all the jetting specs. After talking with several people I'll list what I've got to date. Riding 6-8000 feet 10-32 degrees F. CPR front mount with a GT25.

Main Jets 127.5
Starter jet 25
Pilot Jets ______??
Pilot screw turns _____??
Needle Clips _______??

Plumbing Questions: Here's what I'm led to believe:

1. Connect the 2 lines from the billet tees to each other via a tee then attach that line to the intercooler?

2. Join all 4 carb boot nipples together 1 end of the line goes to the boost guage, the other end of the line goes to the BOV and a tee from the center goes to the fuel pressure regulator?

3. What becomes of the carb vent lines? Tee'd then attach to the intercooler?

That should keep me busy for today


Thanks Rx1M5

 

[Trxster]

I think the starter jets stay stock at 75 and the pilots are the 22.5 or 25??? I think the airscrew has always been around 2 turns out. I have been running 17.5 pilots and stock 75 starter and mine seems a little lean at idle (I believe you want to shoot for around 14 and then go down to around 12 at WOT). Needles are easy to adjust on the hill so I would start in the middle position and wait to see where you are running.


1. Connect the 2 lines from the billet tees to each other via a tee then attach that line to the intercooler? YES

2. Join all 4 carb boot nipples together 1 end of the line goes to the boost guage, the other end of the line goes to the BOV and a tee from the center goes to the fuel pressure regulator? YES and try to make sure you use equal length lines on all lines off of carb boots. To do this I took two equal length lines off 1 & 2 and T'd them together and two equal lenth lines off 3 & 4 and T'd them together . The run two equal length lines from those two T's and run them to a 5 way...1 for each equal length piece coming from the carb boot T's and then 3 in the middle for the boost gauge, Bov, and pressure reg. Also, I highly recommend using higher quality line....I used fuel line. I had my old lines just crumble on me a few times out on the mountain where they were just old and heat soaked and the ends just fell apart while I was riding.

3. What becomes of the carb vent lines? Tee'd then attach to the intercooler? My IC has two posts that stick up to where these come off the carb. Not sure where they go on your IC but I believe most run then on the IC side of the carbs.

 

[Rx1M5]

Where'd you get that alu tee between the billet tees on the carbs?

Thanks for the pics by the way.

Paul

 

[lakercr]

Where'd you get that alu tee between the billet tees on the carbs?

Thanks for the pics by the way.

Paul

Mountain Performance for the T's.

 

[Rx1M5]

I've got the billet tees in the carb rack from MPI it's the big one joining those two I'm curious about.

 

[Trxster]

I'm not sure, it was with the used kit when I bought it.

Rt

 

[RED]

This is the proper way to hook up a CPR kit, Use your mpi t's, then all you need to is find a brass t and 3 nipples with the same size of hose as the ones of the mpi t's then go to the outside nipple on the intercooler or the longer of the 2 nipples. The shorter nipple goes to the fuel pressure regulator, I know lots of people will tell you its better to go to the back side of the carbs, if you don't believe me, phone Jeff, he made it. The 4 turbos I put on of his kit, the other 2 I know off are plumbed like this, all ride in the mountains and work very well. The 4 nipples I hooked together with plastic T's, between the middle cylinders put another t, it goes to the boost gauge, the outer ones go to my bov's. With this setup flame out don't happen that often for me, pushing around 21lbs. If you don't like the fuel reg plumbed this way after you try it, you can always move the hose later. Silcone hose is the best to use, takes heat alot better, looks 100% better than ugly gas line, dosen't leak like gas line, seals better, I know Mopac sells it in Calgary, thats where I got mine in Edmonton.

 

[JDMCRX]

who makes those carb caps?

 

[Blue shadow]

RED,one question .The long one with the threads that 3 1/4 inch long from the intercooler ,how far did you screw that in ,or it d ont make a difference .Why so long ,or do you cut it off ?THANKS

 

[Rx1M5]

Red

I will try it as you spec here. One question regarding flame out. What are you running for a plug gap to help with preventing flame out?

Thanks Rx1M5

Carp caps are from Supreme Tool. Do a search on Supreme and you'll find a link on this site somewhere.

 

[rxrider]

who makes those carb caps?

Allen Ulmer (srxspec) selles them

 

[RED]

Blue, the nipple on my intercooler was welded, but some of the others were adjustedable. Other than that don't know anything about it. Not sure if I by into the plug gap, for flame out. The coil will produce enough spark to jump the gap on its own. I have never heard anybody ever talk about the plugs causing the problem. But I have only been into boosted yamis for 3 years, so there is alot of people out there that know alot more than I do.

 

[Trxster]

Red

I will try it as you spec here. One question regarding flame out. What are you running for a plug gap to help with preventing flame out?

Thanks Rx1M5

Carp caps are from Supreme Tool. Do a search on Supreme and you'll find a link on this site somewhere.

I think a number of guys are using the cr10ek's....don't know if it helps but I have not yet had a flame out (I'm only running 10-12psi).

Rt

 

[RED]

Under 12lbs, flame out don't seem to happen that often, but over 20lbs I have had a few more.

 

[Rx1M5]

This might be a stupid question ( not my first one) How does flame out manifest itself? How do you know when it is happening?