I just put a new 2 into 1 exhaust on my 89 FXSTC. The pipes I replaced were basically drag pipes with fake mufflers. When I pulled the old pipes, I found the po had installed torque cones which I left out of the new install.


The New exhaust looks good, sounds good, and I'm consistently getting 53 mpg.


I believe the bike has the original carburetor, What should I look for that would suggest re-jetting>

 

Why do you think it needs to be rejetted? How does it run now, any worse than before with the old pipes? How's the throttle responce? Are the spark plugs hot looking or sooting up? I'd just ride it and feel her out, look at the plugs after a long ride.

 

I don't think it does need to re-jetting but since I completely changed the emission system, I thought it prudent to ask what possible telltale signs to look for.
Also, the instructions that came with the new exhaust said I may need to re-jet.

 

Look at your plugs.
They will tell you what you need to do.

 

But put in a fresh set. Does it pop on decell? If not at least it's not lean.

53 MPG is very good...

 

Here's what the plugs look like.

 

About jets...evidently there are at least two main jet thread diameters. Obviously they install in different tubes. My 87 evo FXST has a CV carb - but its provenance is unknown... I bought a 185 and a 190 at Harley... They don't fit.

a 45 pilot and a 185 main seem about right in my application...

But I closed it up with the old main - a 180 (small OD).

The two different diameters, measured across the brass threads with a dial caliper are
0.183" and 0.228"

I am not familiar with the CV Harley 'tooter".
So this is a heads up, but also a question - when did they make the change from small thread to big thread? Are the tubes interchangeable?

 

Sounds like your carb has been reworked with after market emulsion tube and main jet,possibly the slide,spring,and velocity needle,that is why your harley main jets don't fit,your plugs look a little rich but not too bad,better than too lean,like they said put a new set of plugs,take a good ride,check plugs later,if it's running good no need to fix what ain't broke,nice looking bike

 

Sounds like a Dynojet kit.

 

I was thinking that...

Thanks fellas..

Just took the old gal out on the highway and ran her hard in 104 degree summer heat with 180 / 45 jets and she goes great, maybe a bit rich.

Nothing to change.