Slow jet - stock config

Lurkin · August 15, 2011, 12:20:48 PM

My carbs clogged up on me while I was not riding due to; 100+ degree days;, and a rotator cuff injury. Bike only sat for 3 weeks,,, but it is what it is.

Question to y'awl, I am trying to decide if I should upgrade to 42 slow speed jets while I have it apart. I am currently running a stock air filter and exhaust, have 105s, and an additional shim and run 2 3/4 turns on the pilots. Sooo, clean the 40s and move on, or acquire a set of 42s as long as it's going to be opened up?

Rod...

TLRam1 · August 15, 2011, 03:31:40 PM

Without elaborating much, I would clean and move on.

hootmon · August 15, 2011, 03:55:17 PM

If you plan to go to a K&N in the future, I'd go ahead and move up to the 42's now, otherwise, you can take Terry's advice..

Lurkin · August 16, 2011, 08:06:00 AM

Thanks for the input gents. No K&N planned, I've done enough research in the air filter media area to not fully trusted oiled gauze as an effective filtering media.

One thing I did forget to mention though, I am running a Dyna ignition module, if that affects any jetting thoughts.

roboto65 · August 16, 2011, 09:58:10 AM

It does not affect jetting just timing so clean and ride.

Wrench Session this Saturday in Conroe.

Lurkin · August 16, 2011, 12:21:45 PM

Since it will just barely start with full choke, and will die with ANY actual throttle, I think it will take way too long to get to your place at idle (I'm in Pearland)

Thanks for the reminder though.

Greg Cothern · August 16, 2011, 06:16:14 PM

Millions and millions of K&N air filter users out there cant be too wrong......

I personally would not go with 42's in stock configuration without K&N. I think it would be too rich especially with the 105's and the stock exhaust.

But this is my personal opinion..

Lurkin · August 17, 2011, 09:06:52 AM

Quote from: Greg Cothern on August 16, 2011, 06:16:14 PM
Millions and millions of K&N air filter users out there cant be too wrong......

I personally would not go with 42's in stock configuration without K&N. I think it would be too rich especially with the 105's and the stock exhaust.

But this is my personal opinion..

Thanks for the input, looks like 40s are more than sufficient for my config.

As far as the K&N goes, there's just too much data on filtering ability and oil analysis results that point to increased silica (combusted dirt...) levels with an oiled cotton gauze filter (K&N). Now,,, what I don't know is if the increased silica level is sufficient to be a concern as K&N users are definitely not grenading their engines. But for me it's sufficient evidence to avoid unless there is a significant need, like no more OEMs...

Jigger · August 18, 2011, 03:36:57 AM

When I had my carbs rebuilt they put a jet kit in it which were 42's. At the time they also put on a K&N filter. I would imagine that the K&N filter would be able to trap more silica an dirt then a stock paper fiter. If silica was getting down into the oil pan. Then I would imagine that the oil filter would collect most particles floating around in the oil.

Lurkin · August 18, 2011, 09:21:18 AM

Quote from: Jigger on August 18, 2011, 03:36:57 AM
When I had my carbs rebuilt they put a jet kit in it which were 42's. At the time they also put on a K&N filter. I would imagine that the K&N filter would be able to trap more silica an dirt then a stock paper fiter. If silica was getting down into the oil pan. Then I would imagine that the oil filter would collect most particles floating around in the oil.

Not true. Air filter construction, like any other construction/manufacturing is a trade off. In the case of an air filter, it's air flow vs. air filtering. Can't optimize both, to get better at one, the other must suffer. Oiled cotton gauze filters optimize on air flow, which allows more dirt to pass, that dirt then is combusted, turning into silica in the oil. Oil filters do not trap all of this silica. An oil analysis shows the silica levels.

If you want more details on this, start with bobistheoilguy.com. Many oil analysis results along with filters used to help correlate those results.

Again, what I don't see is K&N users with engine failures or premature oil related failures. So what I don't have is any evidence or empirical results that the increased silica levels actually cause long-term damage. But, it's enough that I avoid them.

...my opinion based on what I've researched, driving my own behavior. I don't spend any time preaching (I hope), just trying to pass on what I've researched if I see something that I don't think is correct.

Lurkin · August 29, 2011, 07:48:36 AM

Just an update, I pulled my carbs this weekend and the slow jets were completely clogged. I couldn't blow any air through any of the jets. I've had this bike for over 5 years and have had the carbs off 3 times now, this was the worst it's ever been. I knew it was bad when it would only start with the choke fully on, and any throttle input would kill it, but it surprised me given that it's been ridden at least every 3 weeks (torn rotator cuff and heat have limited my normal riding), and it had a healthy dose of Seafoam in the tank. But, oh well, watch those jets, doesn't take much anymore,,, apparently.

lragan · August 29, 2011, 03:26:14 PM

It doesn't take long, and when they are clogged all the way to closure, it is highly unlikely that they can be opened by chemical means (read:Seafoam) without removal.

Magnas are great bikes, but this aspect is about even in annoyance level with the nagging fear that a regulator/rectifier will die. Compared to these two issues, all others are minor.