Re: rejetting after putting sportster pipes......Rejet Kits

CX Customization and Modifications

rejetting after putting sportster pipes


medic0970 11-28-2007, 10:04 AM
How easy is it to rejet my carbs on a 79 CX 500 after putting sportster pipes on it, and what would you recommend for the best mileage?
Life is too short, so why not live it on 2 wheels.

Re: rejetting after putting sportster pipes


CXDowner 11-29-2007, 7:11 PM
It is a rather straight-forward process. Standard jetting is #78 and 112 (secondary and main respectively). Go to the links tab on this site and click on Rob's fix it page. He gives a very detailed set of instructions on carb removel and assembly/dissassembly.
Good luck on your project.
TCG
1979 CX 500
1999 Concours

Re: rejetting after putting sportster pipes


trev_h 12-01-2007, 5:02 AM
Hi, I don't see why you would need to rejet, I have sportster pipes on 2 of my bikes  and they made no difference to performance or gas mileage. They sound a little quieter at low revs and a rasp to them at high speed. They are a lot better made than the Honda mufflers.
cx 650/500c special, 78 500z, 94 bmw k75rt

Re: rejetting after putting sportster pipes


TechJD 12-03-2007, 2:30 AM
 trev_h wrote:
Hi, I don't see why you would need to rejet, I have sportster pipes on 2 of my bikes  and they made no difference to performance or gas mileage. They sound a little quieter at low revs and a rasp to them at high speed. They are a lot better made than the Honda mufflers.

if you havent noticed a differance in performance then maybe you need to rebuild your carbs :)
mine and others have noticed a positve differance in responce and power


1981 GL500I

Re: rejetting after putting sportster pipes


RichD 02-17-2008, 1:41 PM

Medic,

How did the rejet turn out?

I installed some screamin' eagle mufflers awhile back and ended up taking them off due to the noise at freeway speeds. They sure sounded nice below 5000rpm though. I stll have the "H" box on my bike. I'd like to put them back on if I can figure out how to tame the high rpm noise. I'm running 2006 Dyno glide stock mufflers now and they are quiet but deeper sounding than stock.


Rich DeMartile

Re: rejetting after putting sportster pipes


Anonymous 03-04-2008, 10:51 AM
My 1980 has sportster mufflers with 115 jets. At 2200' elevation they work great. I have done no other mods to the carbs than the jets and the bike runs as smooth as can be.

Re: rejetting after putting sportster pipes


Cixxer_80 03-04-2008, 10:54 AM
I run 115 jets on my 1980 custom with sportster mufflers and it runs and sounds great. I live at 2200' eleveation and that's the best combination here. I only have 19K on the bike so the cars are still in excellent shape.

Re: rejetting after putting sportster pipes


dccoleman 03-11-2008, 1:41 PM
 Cixxer_80 wrote:
I run 115 jets on my 1980 custom with sportster mufflers and it runs and sounds great. I live at 2200' eleveation and that's the best combination here. I only have 19K on the bike so the cars are still in excellent shape.


What kind of mileage you getting now? I went from 55 to 44 mpg. I'd like to get some of that back if I can. I have a friend who rides a Yamaha XS650 and he gets better gas mileage (even though he has a hard time keeping up).

***********************
1979 CX500 Deluxe

Re: rejetting after putting sportster pipes


vevogel 03-16-2008, 9:04 PM
Any one have pictures of there CX/GL with the Sportster or Dynaglide mufflers? I stoped by the local harley shop Saturday and they said I am welcome to anything in the scrape bin!
1979 CX500B The Red Dragon

Re: rejetting after putting sportster pipes


RichD 03-16-2008, 10:55 PM

I'll see if I can take a picture tomorrow and post it here for you. I have the Dynaglide mufflers. 2006 model I think. They are longer than the Sportster mufflers by ~3" or so. Not as long as the stock mufflers though. There is a minor loss of ground clearance from the center stand tang hitting the large diameter section of the Dyna muffler on the left side so the stand hangs a little lower. The Screamin' Eagle mufflers are shorter and smaller in diameter so not much of an issue as I remember. It's not much of a problem except on a large bump on a hard charging left-hand turn. You'd have to extend the muffler rearwards about 6" with a straight pipe section to get the center stand to sit right.

The other downside that I didn't notice until afterwards was the rear axle can't be removed unless the left muffler is removed due to interference. The stock muffler angles upwards enough to clear the rear axle.


Rich DeMartile

Re: rejetting after putting sportster pipes


fll1441 03-17-2008, 12:45 PM
Here's a link to a picture on Shep's webpage:

http://www.geocities.com/sheppola/cx500/pinky.jpg
1982 CX500 Custom

Re: rejetting after putting sportster pipes


malcolm in UK 03-20-2008, 6:55 AM

On my JZR 3 wheeler, I have no H-box, headers about 5' long, and Harley Road King Catalyst model silencers (I'm in the UK, we don't have Mufflers).

I haven't re-jetted the carbs from standard, and have no problems taking the motor to 8500 revs, I'm sure it would easily go higher, I just choose not to do it.

MPG around 40 (Imp gallon), but it's pulling much more weight than when in the bike, and also I have a 15" car rim mated to the rear hub, so I reckon the gearing is a tad lower - around 10mph per 1000rpm in 5th.


malcolm in UK

Re: rejetting after putting sportster pipes


malcolm in UK 04-01-2008, 6:38 AM
 malcolm in UK wrote:

On my JZR 3 wheeler, I have no H-box, headers about 5' long, and Harley Road King Catalyst model silencers (I'm in the UK, we don't have Mufflers).

I haven't re-jetted the carbs from standard, and have no problems taking the motor to 8500 revs, I'm sure it would easily go higher, I just choose not to do it.

MPG around 40 (Imp gallon), but it's pulling much more weight than when in the bike, and also I have a 15" car rim mated to the rear hub, so I reckon the gearing is a tad lower - around 10mph per 1000rpm in 5th.

 

I've now fitted another set of (non-Cat this time) Harley silencers, again Road King or the like (not Sportsters, these are too big), and again, I feel there's no need to rejet, the motor revs right through to as high rpm as I'm prepared to take it.

Bought them off Ebay, virtually new £9.99  ($18 - $20?). Seller was local, so no P&P costs either.  Bargain, methinks.


malcolm in UK

Re: rejetting after putting sportster pipes


BearCX 04-01-2008, 10:18 PM
I believe that removing the baffles and/or mufflers, you run the risk of running your engine lean. Possibly burning out a valve. I run air pods on my '78, and changed jets on the bike. (120/90.) Thanks Glen. Uses a little more fuel but man, did it wake the old girl up !!

Remember, you cant get performance without sacrificing economy. Ask any drag racer.

If you're still in control...You're not going fast enough.

Re: rejetting after putting sportster pipes


vevogel 04-02-2008, 9:50 AM

When I had my bike made road worthy last fall, 15 years without being started, I had to go through two other sets of carbs before getting on to work.  The mechanic said the final set had been re-jetted already, not sure what size, but that it ran ok regardless.  I trashed the original air filter about two months ago and put in a K&N H-500, what a difference.  As the left muffler (silencer) was rusted through at the throat just after the Hbox it started to bog down when accelerating/revving.  I am still trying to find mufflers to replace the originals but I have since put in 1 3/4 inch galvanizes exhaust that I tapered at the end to create backpressure.  Sounds a bit louder, nice and throaty, and runs fine.  There’s just a little lag when accelerating now.


1979 CX500B The Red Dragon

Re: rejetting after putting sportster pipes


VTWINRUMBLEKETTLE 04-02-2008, 11:33 AM
Just had to chip in on the back of bears comment re drag racing.i ran a gsx1100 for ten years on the strip turning consistant low 10s /quarter.carefully tuned she had 165 hp at the wheel +averaged 45mpg on the motorway,as good or better than the std bike.Depends where you chose to get your performance!

Re: rejetting after putting sportster pipes


vevogel 04-02-2008, 2:46 PM
165hp that is what the new 2009 Yamaha VMax is suppose to be pulling this summer. I just cannot hold on THAT well!!!
1979 CX500B The Red Dragon

Re: rejetting after putting sportster pipes


dozer1 04-02-2008, 6:02 PM

"165hp that is what the new 2009 Yamaha VMax is suppose to be pulling this summer. I just cannot hold on THAT well!!! "

Trust me, all you want to do is hold on for dear life. It rips your arms from the sockets, but it just nuts to ride.(and this is coming from the older version with only about 150hp after mods)


1980 CX500 Ratbike "Stella"
1979 CX500 Deluxe(Parts)
Dozer1 AKA Snowplow

http://www.youtube.com/watch?v=6TK5VY90ILs&feature=related

Re: rejetting after putting sportster pipes


vevogel 04-02-2008, 9:27 PM
I have a friend who picked up a used one that had been damaged, cheep. He put it back together and now just eats up his H-D buddies, but with all that noise it's no wonder, unused horsepower going out the tailpipe. Although I like the sound of my CX500(A) with straight pipes I hope to get some mufflers on her soon. Maybe she'll run much better with some baffles?
1979 CX500B The Red Dragon

Re: rejetting after putting sportster pipes


Anonymous 04-02-2008, 10:02 PM
 vevogel wrote:
I have a friend who picked up a used one that had been damaged, cheep. He put it back together and now just eats up his H-D buddies, but with all that noise it's no wonder, unused horsepower going out the tailpipe. Although I like the sound of my CX500(A) with straight pipes I hope to get some mufflers on her soon. Maybe she'll run much better with some baffles?


With the crossover in place (assuming yours is still integral) I've noticed very little difference with/without mufflers performance wise.  After hearing the mighty CX without mufflers, I will NEVER run anything but straight pipes, it's like Crack or Meth-once you're used to the rush there's no going back. 

CED

Re: rejetting after putting sportster pipes


vevogel 04-03-2008, 1:54 PM
She sure does sound sweet!  I just have to figure out how to tune the pipes to get the best sound and performance.  I am thinking of adding some 4 inch baffles to add back pressure and to keep her from backfiring during deceleration.  Once I have the measurements all figured out I need to see about reproducing the same effect with chrome pipes.  The galvanized exhaust pipe is good for getting her back on the road but it does look ruff, but the pipe clamps proved a good way to mount the pipes to the existing muffler mounts.  I will try to get a pic this weekend and post it.
1979 CX500B The Red Dragon

Re: rejetting after putting sportster pipes


BearCX 04-04-2008, 12:20 AM
Thanks VtwinRK, didn't know that was possible.....not true for car racing, I should have been maore specific.
Mind you the Gixxer was a hell of a bike. Cheers.

If you're still in control...You're not going fast enough.

Re: rejetting after putting sportster pipes......Rejet Kits


ROne 05-28-2008, 7:27 AM
Hey BearCX,

Just wondered if you could direct me on where to get Carby Rejet Kits for my '78 CX as I asked my local cycle guy and he is unsure that they even made them for that model?   Obviously you can but not sure where to get them?  I'm based in Victoria, Australia and I'm also interested in getting rid of the 'airbox' and adding 'Pod Style' filters....any idea what ones I can get for those carby's?

I've also read about 'Velocity Stacks' straight on the carby's, apparently they work well have you heard and once again, not sure which would be best?

Any advice is appreciated, thanks.

Cheers,
ROne

Re: rejetting after putting sportster pipes......Rejet Kits


BearCX 05-29-2008, 12:50 AM
Cant for the life of me, remember their name...something like Sirius.com. Got off ebay. bag of 6 or 8, all different sizes.
And velocity stacks are LOUD. You can hear the air rushing in, even with a helmet on.!! No noticable power gain. Try to get some with mesh over the intake horn. (especially if you have kids) good place to put stones, bark, leaves etc.


If you're still in control...You're not going fast enough.

Re: rejetting after putting sportster pipes......Rejet Kits


Anonymous 06-02-2008, 6:41 AM
Hey BearCX,

Thanks for the tips (re: carbs, etc.).  Unfortunately, so far all the leads I've been making have been turning up empty in regards to finding a Rejet Kit for a CX500, I tried that website above you gave but it linked back to some Radio Station in the USA....guess that's not the website :)   

I'm real keen to get this done to the beast but so far haven't been able to locate these jets. Would prefer to buy local (in Australia) but if I have to buy from overseas I will, anyone have any contacts for me to buy a kit to rejet the carbs?  (It's a '78 CX500).  Oh, and after some more research, I think I might stick with the Pod Filters and leave the Velocity Stacks alone......might be an overkill for what I want.  I am wanting to get the right advice and links to some good allround mufflers though....or should I stick to the 'Megaphones' I have already?  I do prefer the twin pipe look rather than a 2 into 1.

Cheers, ROne

Re: rejetting after putting sportster pipes......Rejet Kits...damn


ROne 06-02-2008, 6:44 AM
Damn......I forgot to sign in again!  I hate that!.

Re: rejetting after putting sportster pipes......Rejet Kits...damn


wridley 06-02-2008, 7:24 AM
Try this

Willy
1982 CX500C
1980 CX500D
1981 GL500I (wife)

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


ROne 06-03-2008, 2:56 AM
Hey Willy,

Thanks mate......that's the site I was looking for (and thanks to BearCX for suggesting it).  Much appreciated for everyone's guidance, I will be looking into this very soon. Can't wait to give the beast a little more life.  I'm still debating over the 'muffler' scenario though, not convinced as to which way to go but I'll get there......eventually ;)

Cheers,
Rone   

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


Natrik 06-03-2008, 3:51 AM
I put on a set of Harley Fat Bob pipes on my CX and I love them. They look just like the Sporster pipes just larger. They sound great, not really louder, just deeper. I did notice a performance increase as well, and there was no need for rejetting or anything. Highly recommended.....


If it wasn't for physics and law enforcement, I'd be unstoppable.....

1980 CX500 Custom, Hondian (found someone new)
2005 Honda VTX 1800 Retro, customization in progress

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


PirateYarr 06-03-2008, 8:13 AM
I guess I should add my two cents as well.  I have the 883's on mine.  I love them way better style, plus like Nate said, a deeper sound not really any louder.  I too have not rejetted and the performance is just fine and the plugs look good. 

Nate's are actually Harley Street Bobs.

1980 Cx500 Custom "Rusty Bob" - Sold
New Bike: 1999 Honda Shadow Spirit VT1100C

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


Natrik 06-03-2008, 3:20 PM
Ahh, street bobs. I am still very ignorant to Harley names and terms. Btw, is "fat bob" the same as "fat boy"? I keep hearing that term and am still in the dark...

If it wasn't for physics and law enforcement, I'd be unstoppable.....

1980 CX500 Custom, Hondian (found someone new)
2005 Honda VTX 1800 Retro, customization in progress

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


iradiate 06-16-2008, 8:57 PM
I have a shot at a pair of Harley Davidson 1200 Sportster Custom factory mufflers off a 2004 bike. He wants 50 bucks for the pair. Think they would fit and not make the bike really loud? Have no clue about Harley mufflers....I have a 1982 CX500c

:)

Vince

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


Nico 06-16-2008, 9:31 PM
"Ahh, street bobs. I am still very ignorant to Harley names and terms. Btw, is "fat bob" the same as "fat boy"? I keep hearing that term and am still in the dark..."









I'm no Harley guy, but the Fat Bob is a Dyna and the Fat Boy is a Softtail....  

That's about all I know!!  lol 

Dr. Nico
http://forums.delphiforums.com/SoCalHooligans

http://hooligancruisers.proboards102.com/index.cgi


Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


BearCX 06-17-2008, 4:09 AM
Thanks Willy, thats the place. ROne, did mine on the bike with air pods on. Fiddly, but easy enough.
If you're still in control...You're not going fast enough.

Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


ROne 06-17-2008, 6:40 AM
Hey BearCX,

Yep, I think I'm going to do the same. Might try and grab the kits this week or next when some more 'funds' come in.  Will definately do the pods, still deciding on the 'Muffler' scenario though. Not too sure whether to keep the current megaphones or go some Thruxton style mufflers, or perhaps straight pipes?

We'll see.  But thanks guys for the tips and direction, it's definately a good thing these forums. ;)

Rone


Re: rejetting after putting sportster pipes......Rejet Kits...Thats it!


PirateYarr 06-17-2008, 7:28 AM
Iradiate -
Those look similar to the Street Bobs (Natrik's bike), longer and wider than the 883's.  They probably have the same mounting system on the back side as did the Street Bobs.  I'd just make sure the diameter of the mufflers is small enough to fit in the hbox and then it's up to you how to mount them. 

1980 Cx500 Custom "Rusty Bob" - Sold
New Bike: 1999 Honda Shadow Spirit VT1100C
Copyright 1978-2006 Charles E. Smith

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