Expansion chambers

[Stacy1968]

Hello all im new to 2 strokes and am building a rd350. I wanting some feedback on JL pipes and if they are a good choice.

[Seizer]

Hi,

Before buying any chambers for your build, it's important to consider a few things:

What's your budget? JLs are a high end pipe on the upper part of the cost spectrum. They are beautifully constructed and offer different materials and silencer combinations.

How will the bike be ridden? The JL GP pipes are built to make power at the upper RPM range. They also build their Street Retro line which appear to be a more midrange pipe. There are people here who can offer their opinion on the Retro pipes as I have no experience with them.

I have JL GP chambers on my 400 and they're fantastic. Great quality, exact fitment, good power and they're gorgeous.

[Striker1423]

Hi,

Before buying any chambers for your build, it's important to consider a few things:

What's your budget? JLs are a high end pipe on the upper part of the cost spectrum. They are beautifully constructed and offer different materials and silencer combinations.

How will the bike be ridden? The JL GP pipes are built to make power at the upper RPM range. They also build their Street Retro line which appear to be a more midrange pipe. There are people here who can offer their opinion on the Retro pipes as I have no experience with them.

I have JL GP chambers on my 400 and they're fantastic. Great quality, exact fitment, good power and they're gorgeous.

Street Retro's DO NOT fit the RD350 very well. A ball peen hammer and time is what's needed to make them fit. Also, a long chunk of wood to tweak passenger footpegs a bit.

[Djg8493]

Reading through the pipe identification thread is a good place to start, there are also a few other discussions around this topic.
As mentioned budget, type of riding and engine modifications will all factor in. The rest will come down to preference, I have run FPPs and love them, I like the look of DG when you can find them at a reasonable price but am not a fan of the sound or performance.  In the end I just bucked up and bought JLs.  I readily admit however the final decision was more about looks than anything else.  Garrets pipes on here seem to have the best overall reviews from everything I have read.


http://www.2strokeworld.net/forum/index.php?topic=177.msg956#msg956

[Stacy1968]

Thanks for the feedback. I've already split the cases and media blasted everything and have it polished, painted and back together with a Vito's crankshaft. Gary at spec2 did a stage 2 porting, he bored the cylinders and milled the heads as well. I've installed Gary's clutch kit and springs and am going with the vape Ignition/charging system. I got the 30mm round slides and I did order the stainless JL performance pipes. I've built lots of ground up 4stroke jap bikes 1960's-70's but this is the first dealings with a 2stroke. My initial question about the JL pipes is because I was told by a reputable engine builder those pipes are the worst on the market and will not work well with my build, since I had already purchased them and it will be awhile before I get the frame, seat and tail section fabbed i was needing some reassurance those pipes would work well for my engine with the modifications I've made to it. Again thanks for the comments this is new territory for me, perhaps I should've done more homework initially but true to nature I just jumped right in 🤷🏻😁

[m in sc]

they work great. i have a set on my lc hybrid build. have a set of garys f1's on another bike.  the lomas pipes will work well with a ported motor. Id recommend reaching out to john at economy cycle, consider getting a zeeltronic ignition box & programmer. Have that on the bike with the lomas pipes and on my 72 R5 with pipelyne chambers. .

[paul1478]

JL to me are the best sounding pipes and seem to make good power like Mark said with port work.
if Spec 2 built the bike why not there pipes? Just wondering. That is what I have and they make great power.

[Stacy1968]

Thanks guys I feel better already 👍 I choose the jl's because I think they look bad ass and would go in the direction of my build. I know not all expansion chambers are created equal but assuming without investigating (my mistake) that they would be a good fit for my bike and any issues could be jetted or timed out. I was disturbed to hear such bad reviews from a reputable source and had me thinking had I possibly blown a grand on nothing more than eye candy ? I'm sure they will be great , and again thanks for reinforcing what I had assumed. Anyone ever build a oil tank tail section ?

[m in sc]

some tuners hate them. i dotn know why. prob just out of their comfort zone on whatever they have been tuning for the past 40 years.

as far as the oil tank in the tail, i did it to an S2 years ago. look at overflow containers for a car radiator. cheap and effective.

[teazer]

Last RD350 I repaired came in with JL pipes.  They are gorgeous and sound great and make great power.  Admittedly I spent time running simulations on different port specs to match the pipes.  Loved those pipes on that bike.

My own RZ350 came with Spec2 pipes and they are really sweet.  also a great sound and nice powerband, but with stock porting perhaps slightly less manic than the JLs. 

If someone was to buy a box load of different pipes and run them on a few sets of different port configurations, I'd love to see the results.

[2 Smoker]

I have also not purchased chambers as of now and have come across these, anybody ever run them.
These in the photos are tight with retaining the stock foot pegs and looks like uncut center stand brackets on the frame.
K2 TEC
http://www.moto-works.jp/k2tec/rd400.html
Developed for street use.
Provides increased torque and throttle response at Mid RPM range.
Carburetor jetting is not needed for street use.
For use in racetrack, where prolonged high rev situation is necessary, increasing main jet setting is recommended.
Exhaust pipes are spring jointed to deal with vibration.
Chambers are build to order and lead time is about 4 weeks from the date of order to ready to ship.
NOTE:Chambers might slightly interefere with bike's frame caused by indivisual frame difference.

Chambers on above link will fit on your 1975 RD350B AC, but might require some modification.
2 into 1 system listed will not fit for sure.

Shipping fee is US$220 to USA.

Best Regards,
Rick
Moto-Works.jp

Location Japan

[m in sc]

ive never had a chamber not affect jetting, even those shitty period j&r power pipes. well, they were ok but still.

[Striker1423]

I have also not purchased chambers as of now and have come across these, anybody ever run them.
These in the photos are tight with retaining the stock foot pegs and looks like uncut center stand brackets on the frame.
K2 TEC
http://www.moto-works.jp/k2tec/rd400.html
Developed for street use.
Provides increased torque and throttle response at Mid RPM range.
Carburetor jetting is not needed for street use.
For use in racetrack, where prolonged high rev situation is necessary, increasing main jet setting is recommended.
Exhaust pipes are spring jointed to deal with vibration.
Chambers are build to order and lead time is about 4 weeks from the date of order to ready to ship.
NOTE:Chambers might slightly interefere with bike's frame caused by indivisual frame difference.

Chambers on above link will fit on your 1975 RD350B AC, but might require some modification.
2 into 1 system listed will not fit for sure.

Shipping fee is US$220 to USA.

Best Regards,
Rick
Moto-Works.jp

Location Japan

I looked into them... I think they look absolutely B.A. However, the price tag had me go with a used set of JL's. But.... the future.... I kinda really wanna try them lol.

[RDFL]

I'm very curious too will try one eventually, probably the chrome Kerker looking ones.

[Czakky]

I agree they look super cool, would love to hear how they perform.