Anyone with straightpipe+baffle experience??

AS I said not all bike are the same. I might start with the jets matching but I would also try them off by the same as stock. Letting the bike tell me what it needs.
Leo.
 
thielb said:
Right, I understood the necessity of rejetting with the pods, I was just wondering if I can go with the same size main for each side or if I would still need to use different sizes. If the need for different sized mains was the design of the stock airbox, would matching mains be acceptable after installing pods?
Click to expand...

If you switch to pods, you will be able to match the jets. It is the stock airbox that restricted airflow to the right carb on DOHC motors. Look at where the battery is mounted - in (yes, IN) the right side of the airbox. :doh:

I've got pods and free flowing mufflers and I've found that 45 pilots, needle up one notch, and 150 mains is the trick. Along with adjusting the pilot screw and float levels. I posted a link to a good article on CV carb tuning. Search for it, read it, and wonder why you are getting into all this... :doh:
 
Your mains are 127.5 and 117.5 on the manual as I read them start by going up 1 jet size as in increments 2.5.For example if your left main is 127.5 it would be 130. Say the right jet size is 117.5 then the next size up would be 120.If I got my figures correct this would be the 1st starting point.I didnt see your pilots but if you only go up 1 size on the mains then the stock pilot should be fine.Now depending on what your bike tells ya,you may have to go up 2 sizes each on the mains and in that case increase your pilot up 1 size.By chance if you have to go larger on the mains which you shouldnt you pilot size being 1 up from stock should be ok.Just remember this once you get this all togetheryour going to fine tune with air and fuel jets and then by syncing them.Now some may differ on how I synced my carbs cause I didnt use a nanometer but I tuned it by sight and must have got it pretty dam close.Knock on wood my bike runs totaly better than last year.I dont use the kick start much only on my good days I have bad knees and back.But when I hit my electric the engine only makes a half a turn before it fires up.I hope all this babbling helps you out.
 
I have straight pipes and pods and it runs pretty good. With propper tuning the bike will run better with less air restrictions, but it is hard to get the tuning right on. I have tried three different size of mains. 127.5 and 117.5 were the stock sizes. It was extremely lean when I ran stock with the pods and straight pipes. I bumped to a 132.5. Still to lean. So now I am running a 135, and it is good from the look of the plugs. There is still a sight crackle of exhaust when I let off throttle in high rpms but Im guessing the thats due to a lean pilot(or so I have been told). So got to change that. Also you can adjust needle hight to smooth out the mid range rpms.

Its kind of a commitment if you change the air system, but its fun to try different carb set ups and see how they react differently with the engine.
 
16VGTIDave said:
If you switch to pods, you will be able to match the jets. It is the stock airbox that restricted airflow to the right carb on DOHC motors. Look at where the battery is mounted - in (yes, IN) the right side of the airbox. :doh:

I've got pods and free flowing mufflers and I've found that 45 pilots, needle up one notch, and 150 mains is the trick. Along with adjusting the pilot screw and float levels. I posted a link to a good article on CV carb tuning. Search for it, read it, and wonder why you are getting into all this... :doh:
Click to expand...


I actually accidentally stumbled on an easy fix for that; the screw would not come out of the air box cover no matter how I tried and I had top break the cover to get it off. The air filter still goes in and seals, but better airflow. I imagine I will go through filters faster, but not a huge problem for me really. I've even shop vacced a dry filter once or twice to get a long good life from them.
 
16VGTIDave said:
If you switch to pods, you will be able to match the jets. It is the stock airbox that restricted airflow to the right carb on DOHC motors. Look at where the battery is mounted - in (yes, IN) the right side of the airbox. :doh:

I've got pods and free flowing mufflers and I've found that 45 pilots, needle up one notch, and 150 mains is the trick. Along with adjusting the pilot screw and float levels. I posted a link to a good article on CV carb tuning. Search for it, read it, and wonder why you are getting into all this... :doh:
Click to expand...

Thanks for all the advice guys, appreciate it. Lots to roll around in the ol' noodle. The more I find out about the change to pods and pipes (particularly having no clue how to go about the battery after removing the stock airbox), the more I see myself seriously messing up a good running bike that I need to get to work every day. Good call Dave. Would definitely like to get new exhaust and pods and all that good stuff but may have to wait until I can make a proper project out of it. Kinda psyching myself out :confused:
 
Not sure if I'm late to the party, but here is a short clip of my bike with straight-pipes. I jetted pretty similar to Scorpio except that I leaned out the needle a little, but I think I might need to richen it back up as I'm running into a slight stumble in the mid-range if I am holding the throttle then try to take off.

 
For those guys running straight pipes and the stock headers, what did you do about the double walled pipes? Did you have to run a reducer to the extra pipe you welded on?
 
markjs said:
I actually accidentally stumbled on an easy fix for that; the screw would not come out of the air box cover no matter how I tried and I had top break the cover to get it off. The air filter still goes in and seals, but better airflow. I imagine I will go through filters faster, but not a huge problem for me really. I've even shop vacced a dry filter once or twice to get a long good life from them.
Click to expand...

Sorry, but no you didn't fix it. Unless you removed the battery mounting completely, the right carb inlet is shrouded. Full throttle airflow will be restricted, hence the need for a smaller main jet in the right carb.

I spent hours looking at the air box last summer before deciding to carve the front of it off and install pods. There are two layers to the front of the air box. The outer layer that the intake boots attach to, and an inner layer that the air filter seals to. Take a closer look and make some measurements. You will see what I'm describing.
 
thielb said:
Thanks for all the advice guys, appreciate it. Lots to roll around in the ol' noodle. The more I find out about the change to pods and pipes (particularly having no clue how to go about the battery after removing the stock airbox), the more I see myself seriously messing up a good running bike that I need to get to work every day. Good call Dave. Would definitely like to get new exhaust and pods and all that good stuff but may have to wait until I can make a proper project out of it. Kinda psyching myself out :confused:
Click to expand...

Waiting would be a good decision! Unless you want to make a POS out of your bike and then have to patch it together before riding it again.

Take your time, do some research, make some plans, save up some money, and do it right the first time!
 
Sorry to bump this one again, but it seems to have gone mostly toward a conversation about jetting.

In regards to baffles in straight pipes... has anyone found a cheap solution that will significantly reduce volume? Or, even just enough to feel OK about riding through a neighborhood at night?
These are a the types of options i'm looking through - http://www.motosport.com/cruiser/search/?textsearch=baffle

Some are basic $5 baffles that don't seem to do much.
With the others, there is a little more going on.

Sorry if I mentioned this in another thread.
 
The volume of exhaust coming out of the pipes can not be reduced. All the exhaust has to come out somewhere, most use the exhaust pipes, some just let it leak out. Now if your talking about the noise volume, mufflers help there. Not only quieter but easier to tune the carbs to.
Now if you just have to run noisy exhaust then when you are trying to get through a neigborhood quietly, shut the bike off and push it. :laugh: :thumbsup: :bike:
Leo
 
So just to clarify....I have a 1980 XS400, so that is sohc. Pod filters. Straight pipes. therefor, my jetting in both carbs will be (or should be) identical, is that right? sorry if i ask any stupid questions, first time bike owner, just trying to learn!
 
In a perfect world, yes. In the world we live in, it is a definite possibility that they may need to be different. Do what works the best, or what is easiest for you.
 
Just asking but do you all your neighbors go to bed at 8-9pm?Im running harley mufflers that are 24" long.The only thing I can do is coast in at idle to be quieter.I supposed if I wanted quieter I could get some baffles to put in them.
 
I'm just wondering.... I have a restored XS400 that had been sitting a long time and also took a long time to get going. LOL. Anyway, I removed the baffle on one side and the other side (Of course) is stuck. But my question is, was there ever fiberglass around the baffles in the stock model? I am planning to take out both baffles and wrap with 1/2"fiberglass to add back pressure and of course, quiet it down a bit.

Main reason is, it won't idle at all, but is improving as I run it, so... I found a real cool removal tool here:

http://www.randomexploits.com/projects/motorbikes/tuono/exhaust_derestriction.htm

I'm going to build and try it, but if back pressure is important to enable better idling, then I guess I am on the right track. Any comments?

I know. Why would anyone want it make it quieter, right? Well, two reasons. I am an old gieser for starters and like a low throaty sound rather than loud crackles. And secondly, live in a small city with no freeways and lots of side roads that lead to fishing spots. I get up before sunrise to go fishing so a quiet departure would be appreciated by my neighbors. They have been through a lot of noise with all of the revving and backfiring as I was tuning and timing, so, there you have it.
 
Loud pipes don't save lives, but they do annoy voters!

You may be better served by replacing your mufflers. I'm currently running a pair from an older HD Sportster. They are heavy, but reasonably quiet. And the bike runs well with them now that I have the jetting correct.
 

Similar threads

Lego
Exhaust headers diameter
Replies
1
Views
2K
16VGTIDave
16VGTIDave
S
Stock exhaust legnth on 79 XS400F ?
Replies
3
Views
1K
xschris
X
Wolfe_11B
Been a while... Updates!
Replies
6
Views
1K
BBS360
BBS360
C
Rear Disc Conversion/Rearset Addition
Replies
13
Views
4K
Charles
C
Back
Top