First time post here. I've been doing a lot of reading and learning on this forum. You guys have provided a massive library of information, but I've finally reached the point of need to ask for help. Thanks in advance!

Just aquired my fisrt HD last fall. A a very pretty 1999 Dyna wide glide with the 88TC engine. The cam tensioner failed so I upgraded to the S&S gear drive with .510 lift cams. Now im getting carburetor pop off idle. Adjusted idle mixture screw out (richer) four turns. Almost lean enough but need to re-jet. Have pulled carb and pilot jet. I know I need to go one or two sizes larger. However I cannot determine what size the pilot jet is that I have now. I'm pretty sure its not stock because of the Thunder Header pipe and aftermarket air cleaner already on it. Is there a way to determine current piolet jet size by looking at it for measuring it?

Thanks again!

 

You need the Micrometric 2000 micro size ruler with laser calibrator.

Actually it's engraved on the jet. You may need a magnifier to read properly.

The one thing I'd suggest - Nothing you indicate justifies a change in mixture that won't work with your current setup. You may have a leak somewhere which will be way more of an effect on a/f mixture than jets. After checking/resolving leaks - then play the jet game.

 

I have had the numbers on a jet so small it took a jewelers magnifying glass to see

Try what Jesse said first

 

Thank you JesseDyna. I appreciate your effort to help me not fall into a "rabbit hole" by suggesting a possible different or less difficult issue. However I did not have the off idle pop/spit/cough before upgrading cam size. Also the reputable mecanic that did cam upgrade said his Dyno machine says its a little bit too lean. He suggested it needs 1 to 2 size larger jet. I've opted to do this myself as I'm fairly mechanically inclined and to save some $ on labor.

Could you please offer a little more info about where on the pilot jet the size is etched. I see it clear as day on top of the main jet, but I see notheing on the pilot. Is it on top of the head like the main, or on the hollow tube shaft of the jet?

oh. Also as I turned the idle mixture needle out the frequncy of the popping lessened. I'm fearful of adjusting the needle out any further as I belive it comes all the way out not too much further from the 4 turn out I'm already at.

Thanks again Jesse. I do appreciate all the input I can get.

 

The stock '99 jets show a 42 pilot and a 180 main. In '02 the jetting increased to a 45 pilot and a 190 main for the same bike. I'd at least start there. I have an '02 88" with basically the same cam and run a 46 pilot with a 195 main. You can get jets here. https://cv-performance.com/jets

 

Thanks lt1-xjs. This is interesting info Thank you!

 

The original owner put the thunderheader pipe on it many years ago. I've heard its not possible to run that pipe without increasing jet size, but I don't know that this is true.

What I do know is:
•Idle mixture plug was removed at some point
•Main jet size is 185
• pilot jet has no size marking
• both main jet and pilot jet have a brand marking that looks like a four pointed star or a lop-sided square.

So, if it originally had a 180 Main jet and it now has a 185 Main jet someone has been inside this carb since it rolled out the show room.

This kind of stinks. I want to go larger but I dont know where I currently stand.

I think the approach I'm going to take is assume the unmarked pilot jet is the stock #42 And install the next size larger #45 without making any other adjustments. If it runs the same then I know it's already been upgraded to a 45. If it runs richer then I know I'm headed in the right direction and I can start making adjustments from that point. I doubt it will run leaner with the 45 but I suppose that is possible too.

Can anybody suggest any flaws in, additions to, or observations I need too look for, with this approach?

Thanks again all!

 

Sounds like your on the right track. Start with the 45. Did the motor have the stock cam before you upgraded... If so your probably gonna need a 190 main. But only make one change at a time. If the 45 gets you 2-2.5 turns out on the idle mixture you should be good on the pilot..

 

Yes, engine had stock cams before upgrade.

 

My clearly marked #185 primary jet.
My pilot jet with no apparent size marking. You can clearly see the same branding mark as is on the primary jet.