Curtis Sparks MX pipe - issues

[troybilt]

Those of you that have or have tried this pipe, does your kick starter come EXTREMELY close to the pipe? I'm afraid I'm going to dent this thing...

http://i74.photobucket.com/albums/i260/robltc/DSCN1399.jpg
http://i74.photobucket.com/albums/i260/robltc/DSCN1398.jpg

[hartwill]

My kicker doesn't come that close. However at some random times the whole pipe will blow apart at its connections at the expansion chamber and the exhaust flange. Has this ever happened to you?

[troybilt]

Originally posted by hartwill
My kicker doesn't come that close. However at some random times the whole pipe will blow apart at its connections at the expansion chamber and the exhaust flange. Has this ever happened to you?

Not yet, cause I haven't ran this pipe... Seems to me I read about that before and there was something wrong that causes that. Over on the other site...

[jcs003]

my ESR trx-6 pipe is like this. i made an extended knuckle and it didnt work as well as i had wanted it. i started a thread about the issue on the other two sites, if you care to take a look.

john

[hartwill]

I think the exhaust mount that goes to the motor mount is offset.. can you flip it around? Or put it on the inside of the mount?

[cdrookie]

Originally posted by hartwill
My kicker doesn't come that close. However at some random times the whole pipe will blow apart at its connections at the expansion chamber and the exhaust flange. Has this ever happened to you?


your springs are either too long or not strong enough(ie cheap hardware store springs).

[JM317]

Originally posted by cdrookie
your springs are either too long or not strong enough(ie cheap hardware store springs).

I had the exact same problems with one a few years ago and I used brand new exhaust springs from Moose that were the correct length.

[hartwill]

troy, i lied mine is just as close as yours, mines just not all blinged out like yours so i didnt really give a sh** if it dented up or not. and i had all brand new springs on mine and sealed it up with hi temp silicone and everything and it still blew apart. so i sealed it up again and ran some short self tappers in the expansion connection. if it blows apart this time im buying a different pipe.... its deffinately got a wicked power band though, i think you will like it...

[k7mm]

Hey Troy.My kick starter never came close to the pipe on my 87 or on my LSR.Did you bolt the bottom tab of the pipe to the motor mount?I bolted to the front bolt,out of the two,on the motor mount.It's tuff to get a bolt on those tabs because there is'nt much room.
Keith

[troybilt]

Keith, I haven't bolted that up yet, I need another exhaust bracket... It should help some but still will probably be 1/4" or so of clearance.

Hartwill, As far as sealing, I'm trying something new on this pipe. I picked up a high temp Cat "back-up" seal that is rectangular cross section, fits perfectly... I hate RTV crap gets everywhere... hopefully the seal will work. Keep you posted. I've also got all new springs from TLR-Online, they are stout springs...

[K-Dub]

I have had that problem on other brands of pipes. Both time it was that the end bell where it goes over the exhaust flange wasnt welded on square (or pulled when welded) and came off the engine at an angle. This put the expansion chamber out further than yours, I couldnt think about getting the kicker past it. I had the pipe on a stock flange no problem, couldnt use it with a dual oring flange. Might check that out. Addicted to Mud was a witness to both pipes being this way, infact he is the one that figured it out.

As far as the pipe blowing apart, that is not a pipe problem. Its not one single thing that can cause it every time. Can be jetting, ignition problem, or another type of carb problem. My first 250R I had did this and I changed the whole carb and the problem disappeared. That carb ate plugs for breakfast, I think it was cracked cause no matter the jetting it fouled plugs and blew the pipe apart.

[troybilt]

Seems to me Neil, mentioned that to another rider on the other site, that was having pipe blown off issues... Said something to do with the ignition being too far advanced or something if I remember right, but like K-Dub said could be any number of issues...

[rablack21]

Troy,

I have the very same pipe you do, and mine does the same thing. I thought it was going to interfere when I first put mine on. It comes awful dang close. I am very careful when I kick it over. Other than, not sure what else to do. My FMF pipe never came that close. I guess it's just the way they made them.

[hartwill]

Troy, the only thing I changed on my R was the pipe. My fmf never blew apart like that, but im pretty sure the self tappers will keep it together. The bike is running a little rich and Im gonna lean it out tonight but im not sure how that cuses the pipe to do that. I did read the two stroke explanation under the ARTICLES tab on this site and found it quite interesting, especially the exhaust explanation it kind of cleared up how it works for me. Oh and it only seemed to blow apart like that when you first started it, it didnt matter if the bike was cold or you have been riding it all day. I am going to attempt to find the thread on the other site you spoke of.

[CanuckR]

My Sparks pipe is that close to the kicker too. I ended up messing around with both mounts on the silencer to suck it as far in (to the center) as possible. Then I set up the mount for the expansion chamber after it was sitting where I wanted it.
There is a definitely some pressure on the silencer mounts. But I've run the bike like this for a couple years with no issues.
Ive had my pipe blow apart before as well. Its pretty much always caused by some form of lean issue or timing problem causing backfiring. My bike would run well but when I'd go to start it it would blow the pipe off.

[hartwill]

You think its from running lean? I thought if anything it would be because of it running rich and not burning all of the fuel mixture... In the two stroke explanation I mentioned earlier it said that the cylinder actually pulls unburnt fuel back in from the exhaust.. Someone must know the answer to this.. http://www.atvriders.com/articles/twostroke.html
look at the animation all the way at the bottom.

[2-330s]

Originally posted by troybilt
Those of you that have or have tried this pipe, does your kick starter come EXTREMELY close to the pipe? I'm afraid I'm going to dent this thing...

http://i74.photobucket.com/albums/i260/robltc/DSCN1399.jpg
http://i74.photobucket.com/albums/i260/robltc/DSCN1398.jpg

i want to know how you are holding the kicker there??? lol

i had some ct whale pipe blowing apart problems when i first put it on. the pilot went lean from the prior pipe. mabye start there?

[CanuckR]

Hartwill. Backfiring is almost always a lean condition or a problem with the timing.
Yes you are correct, about the unburnt fuel going back into the cylinder. Its pulses in the exhaust pipe that are pushing some of the unburnt charge that escaped back into the cylinder.
However running too rich will not cause the engine to pop and backfire. (which is what blows the pipe off) Rich will make the bike stumble and get all blubbery. Most bikes that are running too rich foul plugs all the time and have black exhaust spooge oozing out of everywhere. Not to mention not running as hard as they should be.
(sorry for the hi-jack/slightly off topic post)
Derek

[hartwill]

I probly should have started my own post. however, I do foul plugs. Maybe my pilot is lean or maybe I have weak spark. Oh well Ill figure it out eventually.

[CanuckR]

Hartwill do you blow the pipe apart at times? If so you're probably lean on the bottom and rich up near the top, if you foul plugs frequently.

[k7mm]

Troy I do not remember useing a exhaust hanger to mount to the motor mount bolt.I just found a small bolt that was big enough to mount directly to the frame engine mount.I did use a exhaust hanger back on the silencer.I wonder if the exhaust hanger on the mounting tab is bringing it out more?

[DoonRider]

I have the same pipe but I have about 3/8" of clearance. The pipe is touching the frame after it does its 180 after coming out of the head though. Looks like I need to space it out a little by the frame there which will put it closer to my kickstarter as well.

[troybilt]

Originally posted by k7mm
Troy I do not remember useing a exhaust hanger to mount to the motor mount bolt.I just found a small bolt that was big enough to mount directly to the frame engine mount.I did use a exhaust hanger back on the silencer.I wonder if the exhaust hanger on the mounting tab is bringing it out more?

Keith, I don't have anything bolted there right now. I ordered another single hole exhaust bracket. The pipes really should be iso-mounted, or rubber isolated from the frame. They pulse and cause vibration. That's why the stocker has rubber mounts on the entire exhaust system.

With that said, its probably not too big of a deal, I know some aftermarket exhausts mount directly to the frame...

I'll try and move the exhaust closer to the motor, but damn its solid now, without mounting the front mount to the motor mount. I just know with riding boots that pipe is going to get scratched up!!! ...which I can't stand.

[k7mm]

Originally posted by troybilt
Keith, I don't have anything bolted there right now. I ordered another single hole exhaust bracket. The pipes really should be iso-mounted, or rubber isolated from the frame. They pulse and cause vibration. That's why the stocker has rubber mounts on the entire exhaust system.

With that said, its probably not too big of a deal, I know some aftermarket exhausts mount directly to the frame...

I'll try and move the exhaust closer to the motor, but damn its solid now, without mounting the front mount to the motor mount. I just know with riding boots that pipe is going to get scratched up!!! ...which I can't stand. What is your width at the front motor mounts?Here is MY lsr just for comparison sake.The pipes propably should have a exhaust hanger on that tab,but for some reason it just seemed to fit perfect without one.I do'nt understand it?