cpi vs. shearer vs. rocket

[dajogejr]

I too say CPI.

To be honest...I wish someone made a pipe with CPI power delivery with Shearer fit/function.

Gas valve/spark plugs are a pain with CPI or Rockets.

 

I would never go with rockets for a variety of reasons, but most importantly:

1. Fit and finish...if you like smacking your knees or beer kegs, or trying to change plugs through the front of the bike...go ahead

2. The fallout from previous owners. He said/She said, bird shit welding, I ran this, you ran that...blah blah. That made it an easy choice....

 

Other than having to shim out the left pipe a little, I like the fit and function of the Shearers better, spark plugs and gas...no problem. They go up and over the carbs/air filters, no worry about burning them.

 

Ask whom ported your motor what they recommend.

[Bansh-eman]

Hey what does the spark arrestors do?

And DAMMMM who polished those silencers?

Those look awesome.

Spark arrestors are nothing more than a thing built to stop hot carbon or metal from being able to fly out of your pipes and catch something on fire. They are normally made of a screen mesh or many screens and some sort of insert. It's all bullshit, just another requirement the tree hugger where able to get the government to buy off on, because those "possible" stray carbon fragment might catch something on fire, while those bottle rockets, fireworks, and 20 foot race fuel induced bonfires are safe.

 

As for the polishing, I think he sent them to Kiel (theshee)

[jbooker82]

Hey what does the spark arrestors do?

And DAMMMM who polished those silencers?

Those look awesome.

 

Yep like Bansh-eman it is supose to keep hot carbon from coming out the exhaust pipe and starting a fire. It does suck having to run them on a 2 stroke. They need constant cleaning due to the oil pluging them up. On a 4 stroke it isnt a big deal because they dont plug up with oil. All they are is a fine screen dome that fits in the end cap.

 

One of the places I ride at is in a National Forest so a spark arrestor is manditory.

 

theshee polished them for me. I think he charged 60 buck pluse a little return shipping. Here is what they looked like before.

 

[locogato11283]

I too say CPI.

To be honest...I wish someone made a pipe with CPI power delivery with Shearer fit/function.

Gas valve/spark plugs are a pain with CPI or Rockets.

 

I would never go with rockets for a variety of reasons, but most importantly:

1. Fit and finish...if you like smacking your knees or beer kegs, or trying to change plugs through the front of the bike...go ahead

2. The fallout from previous owners. He said/She said, bird shit welding, I ran this, you ran that...blah blah. That made it an easy choice....

 

Other than having to shim out the left pipe a little, I like the fit and function of the Shearers better, spark plugs and gas...no problem. They go up and over the carbs/air filters, no worry about burning them.

 

Ask whom ported your motor what they recommend.

 

dave, i ran rockets for like 6 years. i never had an issue with hitting my knees. and i gotta be on the tank at some of the hillclimbs ive been to. also dune rode it at LS and dragged it there. the whole hitting your knees thing is a big misconception. never happened to me.

 

as far as changing plugs, once youre jetted properly there was no need to pull plugs. at least, i never did. as far as fit and finish goes, my brother and i both had good sets. welds were perfect. no fitment issues or anything. the later model rockets apparently did have some issues though.

 

just lettin you know my experience! :biggrin:

[dajogejr]

I live 20 minutes from Ray (minkia) and I borrowed a loaner set. They had the shit welds on them....and ugly silencers, but...mechanically they were sound. I'm 6' tall. Riding through some trails on private property I kept smacking my knees on them.

 

And they have NO give...so, it literally felt like I was smacking the inside of my knee against a half barrel of beer all the time.

 

Now..the plug changing, I can be for/against. I am a freak when it comes to checking plugs. Not like I pull off on the side of the road to check them..but on my old stocker...I would check them once or twice a day....when I knew we had a 20 minute smoke/BS break.

 

Now...is that overkill? Probably...but, I check my plugs... A lot. Free and 2 minutes is alot easier compared to what could happen if not caught in time.

 

I know you were a big fan of them... After a ride on them in an afternoon...never on my bikes...

[locogato11283]

I live 20 minutes from Ray (minkia) and I borrowed a loaner set. They had the shit welds on them....and ugly silencers, but...mechanically they were sound. I'm 6' tall. Riding through some trails on private property I kept smacking my knees on them.

 

And they have NO give...so, it literally felt like I was smacking the inside of my knee against a half barrel of beer all the time.

 

Now..the plug changing, I can be for/against. I am a freak when it comes to checking plugs. Not like I pull off on the side of the road to check them..but on my old stocker...I would check them once or twice a day....when I knew we had a 20 minute smoke/BS break.

 

Now...is that overkill? Probably...but, I check my plugs... A lot. Free and 2 minutes is alot easier compared to what could happen if not caught in time.

 

I know you were a big fan of them... After a ride on them in an afternoon...never on my bikes...

youre right. checking your plugs 2 times a day is overkill.. i might check mine twice a YEAR! :laugh:

[dajogejr]

I wasn't REAL bad on my trail bike.

On an alky dragster...in my opinion, it's critical....

 

By the way...you should try some small bores on your 10 mil when you can. Matt Shearer himself said that the current big bore pipes (which I have as well) were designed for 535cc Cheetah motors....

 

He told me 300 foot I'd do better with a Small bore. He said guys running the hill (sand mountain) or other LONG, Wide Open Throttle hills can benefit a little on the big bore. From the hill climb videos I've seen of you...you're in/out of the throttle a bit much to qualify...

 

Just a thought...

[baddsheee]

I have no experience with the rockets, but last year I switched from Shearers to CPI's. Of course Shearers had more on top but no bottom. My bike is a duner and CPI's worked a lot better for my type of riding. CPI's have good top, just not as much as Shearer. Can't have everything :shrug: .

[dirtfreak]

id prolly just go ahead and run shearers. great pipe that should work well with that application. you might not give you as much on the bottom as cpi but youll have more on top. if you feel your bottom end is lacking with the shearers gear it down a little and youll still have a ton on top.

 

im not a fan of cpi in any way. i would never run them.

 

honestly on this setup id run the rockets. ive run them on a wide variety of motors and they perform well on all. problem is youll prolly never find a set of them.

 

 

 

 

 

ive seen several set of rockets 4 sale used lately on ebay and craigslist etc.

 

they also still sell them new.

 

greg@rocketpipes.com

Kevin@rocketpipes.com

[bansheejoel]

thanks guys for all the help. Im going to build my engine for "aggressive" dune riding and still drag it a few times. jbooker82 those spark arrestors are amazing looking!!! So with a 4mill dune ported stock cylinder engine with a good set of pipes and coolhead with 20cc domes, +4 timing and a set of different carbs would i need a lockup and/or override?

 

Im going to be running my engine for this year and picking up parts as i go along. Prolly start with a new set of cases and build up from there as i find a "good deal" on parts so i kinda need to know what i need. Thanks guys!

 

BTW what is backloading a override?