What could cause a rich condition

[Trxster]

Ok, I know you are all tired of my rants but I am still working out some gremlins on my front mount turbo.

I have dropped from 132.5 to 127.5 (which was recommended) and now to 125's but still had to have my needles all the way down. Rode again today in 70' temps and sunshine on Mt Baker (still have 230 inches too. My A/F gauge is showing about 13 at idle, dropping fairly linear to about 11 at WOT and 10 psi. My trouble is, I have been told that 127.5's should be the ones even with warm temps yet I still feel that 11 is a bit too rich and would like to be around 11.5 and don't know why I have to have my needles dropped to get there. Do I need to go to 122.5's or 120's????

So, my question is.....with all the little vacuum hoses, T's in the carbs, float bowl lines, etc.....if any of those are leaking, doesn't that cause a LEAN condition??? What could cause a rich condition??? The carbs I recieved have a lot of varnish and don't look like they got summerized at all....maybe they need a good cleaning, but again, could that cause a rich condition.

I am in search of the ever elusive 11.5-12 on the A/F at WOT.

Rt

 

[Freak]

Dont even try tuning around this until you have the billet caps from STM.

 

[Trxster]

I have been told that those caps arn't really needed unless you were running "freak" levels of boost (lol but I am only running 10-11 lbs). Not sure if that is true or not but again, if they did leak would that cause lean or rich condition?

Rt

 

[RED]

The people that make the caps say they leak at 2psi. So every sled must be leaking since atmoshephric pressure is 14.7. I got a set so I didn't have worry about that problem.

 

[rxrider]

NA engines is not seeing much pressure at the caps, boosted sleds are for sure. This is 2 psi over atmosferic and the leaking starts. If caps are leaking the carbs would not run perfectly syncronized. If the caps start to leak at different pressurelevels, slides will not lift in perfect syncronization. It could affect the AFR readings. Hope you can sort it out when you still got snow, LOL, you seem to have a lot where you ride.

 

[RED]

Head up #*$&@ again, figured it out now, later.

 

[Freak]

My caps made the biggest difference at around 7 psi.

 

[Jonny Rocket]

I thought the caps were going to help my sled but they didn't. ( I am sure they didn't hurt either adn they look great) I ended up having to clean my carbs out w/about 2 cans of carb cleaner. then it ran great for 4 rides, then back to crappy again, another can of cleaner, and the last ride it ran great. My issue was a little different as I was getting the proper boost, but anything over 3/4 throttle and it would bog. My A/F guage read lean when this occured. So my problem was with poor fuel.
Anyway, to answer your question about the carb caps, if they leak, the slids will not come up properly and it will run lean, not rich like you described above. So I would say jet down until you A/F readings were where you want them. Even though you are jetted a little lower than most, I have noticed every sled is different. I am at 140's with my clips at #4 and it seems to run just right for my application. Good luck.

 

[Trxster]

What about a leaking header? Also, what if there was a small hole in one of the diaphrams on the carbs? Would those conditions cause a rich problem?

Rt

 

[rideblue]

Does the sled loose power or get blubbery and shutter when A/F is 11. If the performance is not effected, stay on the rich side for a little insurance. every sled is alittle different. I gained 1.5 pounds of boots by jetting up one step richer on the main than what was recommended. you cant always trust what the guages are saying 100%. What is the seat of your pants,your ear or the plugs telling you? if you watch your guages constantly, you will drive yourself crazy!
also, did you check your valve clearance befor intalling the turbo? had the same problem two seasons ago before boost was added. sled would be fat right off idle and no amount of jetting would fix it. checked valves over the summer and all intake valves were tight. some had 0 clearance and were being held open slightly. valve lash adjustment cleared the problem up. had 4000 miles on the sled at the time.

 

[Quicksilver]

Try pressurizing your boosted side of your system. I have a Bender and I found that I had a few small leaks at the turbo. It drove me crazy trying to solve that problem. Someone had a cracked intercooler that had similar problems. I used my leak down tester to pressurize mine but all you really need is a pressure regulator with a air gauge. Then you'll find out if your caps leak and at what pressure. You can test your fuel pressure reg. and your boost controller too.

 

[Trxster]

Thanks guys. I did check my valves and yes, some were that tight. I took it in to the dealer and had them set them all at the outside of clearance specs. Haven't tried a leak down test yet. I think I am going to try a clean set of carbs and replace some of the old vacuum lines with fresh stuff and go from there.

As for running good, it does run good with needles all the way down but at middle clip it was bogging down.

Rt

 

[rxrider]

Trxster - Have you tested your fuel pressure regulator? How about float bowl settings, mine is at 13 mm which is stock. Floats are regulating fuel flow thru the rpm range. Less that 13 mm=richer, more that 13 mm=leaner, BTW the floats should be in perfect sync.

I gained 1.5 pounds of boots by jetting up one step richer on the main than what was recommended. you cant always trust what the guages are saying 100%..

Rideblue - I was beginning to doubt the readings from my boost gauge. Guess my boost went up for the same reason as yours.

I had 10 lbs on low boost and 14 lbs on high with stock jetting. I jetted up from 135 to 140 to cure a lean condition running WOT on the high boost setting. After rejetting boost gauge reads 12 on low and 16 on high. Sled runs great on WOT at high boost, lean popping is gone.

I will install a second boost gauge to verify the readings I get.

EDIT:
Testing is done, my autometer boost gauge is way off, I need a new one. :ORC The control gauge reads 10 and 13.5 lbs of boost and the autometer reads 12 and 16 lbs.

I think my stock carb caps has started to leak. I noticed a smell of gasoline a few rides ago. Yesterday I was out riding and I found out that every time I got into boost it started to smell gasoline, the more the boost the more it smelled gas. When home I checked my gas lines, could not find any leaks there. I noticed that one of the carb caps did not seal properly it looked like it was warped. I could smell gas from 2 of the caps.

I will order and install the STMs asap. 8)

 

[Trxster]

Have not tested the regulator but I do have an inline pressure gauge and when I rev it up I can see the pressure climb. As for the bowls, I set them to 17mm since I'm up in the mountains and will actually be going to 18mm per Outlaw motorsports specs.


I suppose it could be the regulator....how do you test it??