Closing off SRIS recycle system?

General discussion about Street two-stroke Suzuki motorcycles.

Moderators: oldjapanesebikes, H2RICK, diamondj, Suzsmokeyallan

Post Reply
JFISHSOLEVIBE
On the main road
Posts: 102
Joined: Mon May 09, 2011 10:06 am
Country: USA
Suzuki 2-Strokes: 1972 GT380, 1972 and 1969 Honda CB175
Location: Pittsburgh, PA.

Closing off SRIS recycle system?

Post by JFISHSOLEVIBE »

Cheers guys!

Been meaning to drop a line here with this question regarding my 72 GT380. Been wanting to eliminate the recycle lines and was curious as to the best method to close off the ports. Solder? JB Weld? High heat epoxy? If I choose to solder, how should I go about ensuring no solder makes its way too far in?

Thanks in advance!

John
yeadon_m
Road race school
Posts: 792
Joined: Sun Aug 05, 2012 1:18 am
Country: UK
Suzuki 2-Strokes: GT380B, GT550B, GT750A, GSX1400

Re: Closing off SRIS recycle system?

Post by yeadon_m »

John,

It can safely be eliminated and indeed Suzuki did away with SRIS system on the later 380s. The SRIS valves should be removed and replaced with M8 x 1.25 threaded bolts with a 16mm thread length under the head; the head 'should' be (ie originally was on the later GT380s) 12mm AF but you will most likely find modern bolts have a 13mm AF head. Use the same copper or alloy crush washer which is under the SRIS valve.

The brass inlet tubes cast into the cylinders on the intake side must be plugged. If you prefer to do so reversibly, use a piece of rubber tube and plug the end of the rubber tube.

Cheers!
Mike
User avatar
Coyote
Moto GP
Posts: 3404
Joined: Tue Oct 21, 2008 2:41 pm
Country: USA
Suzuki 2-Strokes: GT550x2, GT750, GS1000
Location: Tulsa, Oklahoma

Re: Closing off SRIS recycle system?

Post by Coyote »

Yep. Plain old bolts and washers to replace the valves in the crankcase. Upper inlets behind the carbs can be 'capped' with plain ols vacuum caps - available at any parts store.
If you feel like solder would be more secure, crimp the inlet tube first, then solder up the slit that remains That method is not reversible though. I use (and recommend) caps
I was born with nothing and still have most of it left.

.
1978 GS1000C
1976 GT550 ongoing money pit.
JFISHSOLEVIBE
On the main road
Posts: 102
Joined: Mon May 09, 2011 10:06 am
Country: USA
Suzuki 2-Strokes: 1972 GT380, 1972 and 1969 Honda CB175
Location: Pittsburgh, PA.

Re: Closing off SRIS recycle system?

Post by JFISHSOLEVIBE »

You guys are the greatest! I'm on it!
The Dark Knight
Around the block
Posts: 53
Joined: Mon Jun 03, 2013 10:46 am
Country: America
Suzuki 2-Strokes: GT750M, GT750M, GL1000, KDX200
Location: Fairmont, WV
Contact:

Re: Closing off SRIS recycle system?

Post by The Dark Knight »

Why shut off the SRIS system?
JFISHSOLEVIBE
On the main road
Posts: 102
Joined: Mon May 09, 2011 10:06 am
Country: USA
Suzuki 2-Strokes: 1972 GT380, 1972 and 1969 Honda CB175
Location: Pittsburgh, PA.

Re: Closing off SRIS recycle system?

Post by JFISHSOLEVIBE »

Not the whole SRIS system, but the recycle portion. Just one less thing to leak, break, etc. Can cause big time air leaks if you get a crack in a line. Suzuki got rid of this in the later models.
pull the wire
On the main road
Posts: 105
Joined: Mon Oct 21, 2013 10:04 pm
Country: united states
Suzuki 2-Strokes: 73GT750 75GT750 84RZ350 89 FXRS-CONV
Location: Phoenix, AZ

Re: Closing off SRIS recycle system?

Post by pull the wire »

The brass/plastic filters that screw into the engine case failed on my motor and spread the debris into my crank seals and bearings and caused them to fail. I'm sure age was the cause. I've plugged mine up to prevent that ever again. Some residual fuel/oil will puddle in the lower end but can be blown out easily every time I twist her up!
You gotta pull the wire to go fast
Post Reply