what to use for oil lines?

[olds-455]

Im working on my GT380 cafe build and bought a engine that I was told was a runner. After a cleaning and a good look over I found that the 3 lines that run from under the block to the cylinders are leaking and falling apart. What is a good replacement for these 3 lines? Something that the oil wont destroy in time like it does to rubber hoses. Thanks for any info.

[oldjapanesebikes]

To be clear - you are not referring to the injector lines, but to the three small diameter black SRIS lines at the front of the engine ? The SRIS hoses are still available from Suzuki under part number 09352-20503-600. It not something I personally would do, but some folks just plug them off, and it may suit a cafe project - you can search on this board for previous threads on the topic, plus I'm sure others will comment. If you do plug them off, just make sure you plug both ends.

[H2RICK]

If it IS your SRIS lines that have failed then someone must have been running a synthetic injector oil in that bike at some time. I can't imagine anything else that would cause problems with those lines.
My SRIS lines on Indy are still in perfect condition with no softening/hardening/swelling/cracking/leaking after all these years.
I have used ONLY mineral-based injector oil since I got the bike in 1990......and am not about to change.

[tz375]

Rick, at the risk of opening up another can of worms on oil, are you saying that synthetic oil causes SRIS lines to deteriorate or was it more of a question? If it does have that effect, what about oil seals - or are they a completely different material?

Could it be that ethanol in fuel settling in the cases might be the issue? or maybe that the motor sat for a long time with fuel in the lines instead of oil?

[olds-455]

Its the 3 small black lines. The SRIS Lines yes. They werent original, they were rubber. Thanks

[olds-455]

called up a bike shop and got them ordered. Thanks for the info. Will post pics when its finished.

[Coyote]

Did you remember to order the retaining clips? Part # 09401-04401. Readily available from Suzuki.

[oldjapanesebikes]

Did you remember to order the retaining clips? Part # 09401-04401. Readily available from Suzuki.

Good catch Chris - thanks !

[olds-455]

I did not, thanks again

[H2RICK]

They werent original, they were rubber.

Aha....okay thanks for the clarification. Who knows what someone has used in place of the original lines ??!!??

are you saying that synthetic oil causes SRIS lines to deteriorate or was it more of a question? If it does have that effect, what about oil seals - or are they a completely different material?

TZ, without any precise facts concerning the material used for factory SRIS lines, I wouldn't assume anything re effects of synthetic oil.....BUT.....erring on the side of caution as I have always done, when it comes to old bikes, I will not subject my SRIS lines to any kind of synthetic (or semi-synthetic) injector oil. The original lines were made with mineral oil in mind because synthetics were just barely known at that time, so I'm assuming that the material for the lines would NOT have been subjected to testing with synthetic oil of any kind. Would the lines be compatible with synthetics ?? Maybe someone somewhere has done some thorough testing of that kind of thing but I've not seen any results if they have.
As to the materials of the seals versus materials of the SRIS lines:
I'd be going out on a limb here because I don't have my library of seal books any more and I don't have the chemical composition of the SRIS lines.....but considering the totally different operating conditions for the two items, I'd say that, yes, they are two different elastomers. How/where different ?? Only an industrial chemist could tell me/you that.

Could it be that ethanol in fuel settling in the cases might be the issue? or maybe that the motor sat for a long time with fuel in the lines instead of oil?

Both are real possibilities......but, again, without any proper testing, this is all speculation.
Now that we know that the lines were NOT original Suzuki items, who knows WHAT they were made of ??....so it's no wonder they failed.....for whatever reason.
There is a really good chance that some goof used windshield washer line or engine vacuum line, NEITHER of which is rated for conveyance of gasoline or oil, although such line can be had in close-to-correct sizes.
Sooooo, if it's the right size AND black AND flexible, it must be the right stuff......right ?? (Shakes his head in despair )

[dgloor]

I'm not sure your asumption about synthetic oil is correct. My 74 sat for 30 years and the SRIS lines were brittle. I feel real sure that no synthetics were used since I bought it used in 78 and the only oil I used was mineral oil. I only put oil in it once in 78 before it got parked.
Of course I can't be sure what was used before me, but as was mentioned synth was not popular back then.

[Suzsmokeyallan]

The SRIS lines would more than likely get hard from the heat of the pipes and cases if the bikes ridden often and more so if dripping exhaust sludge is allowed to build up around them accelerating the heating process.
Age would do it too as well as repeated exposure to sunlight or any chemicals that attack the plasticizers in the hoses.
Since they are still available its easy to replace them for minimal cost.