Triple Mikuni thread

[Travel'n Man]

Fuel Pressure? Regulator OK?

Timing?

Have you checked you fuel filters / screens?

Edited June 22, 2014 by Travel'n Man

[madkaw]

Fuel pressure gauges reads steady at idle. Checked the filters/screens when checking floats. I'm not in town right now, but I have decided that first thing I'm going to do is readjust valves. Bouncy idle, low vacuum reading , miss, it's text book tight valve lash-and I know my valves are tight. I went beyond specs to quiet bad rockers basically, and maybe it's tightened up more to the point that the valve(s) is not sealing.

[LeonV]

I'd check compression and then move to ignition. Sounds like you're having spark problems.

[Travel'n Man]

My son and I went to ZDayZ 2014 this year at Tail of the Dragon (my 240 and his 370). Car ran great there but on the way back I fouled out a spark plug. Car ran like crap - pulled off the side of the road - changed all the plugs out real quick - saw the fouled one. Ran great after that. Still not sure what fouled out that one plug.

Have you pulled and inspected each of the plugs?

[Travel'n Man]

I am moving back to a colder plug - just by one notch. My plug strap is showing signs of dark coloration at the very bottom of the strap where it connects to the body of the plug

From: BRP5ES-11

To: BRP6ES-11

[madkaw]

Thank God we got a second page, it takes forever for my phone to scroll that first page-

I am 99% positive a have an ignition problem= Megasquirt. When plugs 4,5,,6 look carboned on triple carbs, then it's probably ignition.

I've always ran the 6 with good results.

[RyanT67]

Great thread, very informative!

Time for me to join in all this fun...

Just got my wideband (AEM UEGO) up and running, and was pretty shocked at the numbers I was reading...

Warm idle AFR @ 1000RPM - 11.4

4th Gear @ 2000 RPM - 12.5

WOT - 2nd gear @ 6000RPM - 10.5

A little rich, shall we say?

Running 44's on a 3.0 stroker.

Pulling the jets tomorrow to see what I have in there. Had these carbs rebuilt just over a year ago by a reputable shop, so all else should be good.

[madkaw]

Yes sir- a bit rich !

Feel free to share you Mikuni experiences- that's how we learn

[Travel'n Man]

Great thread, very informative!

Time for me to join in all this fun...

Just got my wideband (AEM UEGO) up and running, and was pretty shocked at the numbers I was reading...

Warm idle AFR @ 1000RPM - 11.4

4th Gear @ 2000 RPM - 12.5

WOT - 2nd gear @ 6000RPM - 10.5

A little rich, shall we say?

Running 44's on a 3.0 stroker.

Pulling the jets tomorrow to see what I have in there. Had these carbs rebuilt just over a year ago by a reputable shop, so all else should be good.

Do you know your spec's on your set up? Sounds like you need to lean out pilots, and fuels. Let us know what jets you have. Be sure to log all AFR with your data so you know where you are and where you are going.

Edited July 9, 2014 by Travel'n Man

[RyanT67]

Just opened up the suckers today to see what the hell was in them...

Cylinder 1 - 2 - 3 - 4 - 5 - 6

Main air jet 170 - 170 - 170 - 170 - 170 - 170

Main fuel jet 140 - 145 - 145 - 145 - 140 - 140

Pilot Jet 52.5 - 55 - 55 - 55 - 52.5 - 50

Pilot screw was 2 turn out from seated.

Edited July 11, 2014 by RyanT67

[RyanT67]

Can't log, not set up for it. Have the gauge mounted on the steering column though, so my eye is on it as much as it's on the speedo and tach. Might take the car out into the country for a good rip tomorrow, and record the main cluster while doing so. Would be good to review.

Either way, looks like I need a higher number for my main air jets from the looks of it? Not sure what's up with the pilot's fluctuating in numbers like that.

When I bought this car 2 years ago, it ran very poorly. Suspected it sat longer than the previous owner indicated and I took it into a Z-specialist shop to have the carbs cleaned, rebuilt, and properly tuned. It ran me $1350 for this service - I'm questioning that investment now. I knew it was running rich, but couldn't tell just how excessive it was until I got the wideband installed.

Ah well, the rest of the car is doing well, so I am ready to sink some time into this area and learn all I can.

[zKars]

Well getting the same jets in all of them is a good first step. Can't imagine trying to get that thing in balance the way it is. Time to call Todd....

I have 62.5 pilots, 160 main and 200 airs 34mm chokes and idle screws at 1.5ish in my 44's on a 3.1 stroker

EDIT : Sorry, the original statement above said. 150 main was actually 160. 150 was an earlier iteration.

Edited July 11, 2014 by zKars