How To build A Leak Down Tester then test it on your 2 Strok

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LC Cnd
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How To build A Leak Down Tester then test it on your 2 Strok

#1 Post by LC Cnd » Tue Feb 07, 2017 2:44 pm

Interesting tutorial on how to build a leak down tester. However requires a pancake compessor. This one is on a Yamie Blaster (single). 12.5 mins. https://www.google.ca/url?sa=t&rct=j&q= ... 4739,d.cGc" onclick="window.open(this.href);return false;
Also found this tutorial, for crank case leak down testing a crank case with a hand pump. 20 mins.
https://www.youtube.com/watch?v=qoX3SZAMoR8" onclick="window.open(this.href);return false;
Curious to know what someone has used to plug the exhaust and carb openings to preform the leak test on an RD/RZ. The 2nd vid gives me some idea. Going to use a bulb, from a broken blood pressure tester, to create pressure for the leak down tester.

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JonW
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Re: How To build A Leak Down Tester then test it on your 2 S

#2 Post by JonW » Tue Feb 07, 2017 6:04 pm

Maccas on Norbos forum sells a kit for not much money and plenty have used them on there, hes sold lots.
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RuZty
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Re: How To build A Leak Down Tester then test it on your 2 S

#3 Post by RuZty » Tue Feb 07, 2017 7:36 pm

The main thing is to get a gauge with some resolution at low pressure. If you are trying to test at 5-8psi and your gauge reads to 5-120 it won't be too useful. I was fortunate to find a 4" dial 0-30psi in 0.25psi increments for free. I used some electrical conduit fittings that are a nice snug fit into the intake manifolds, one with a hose to the gauge and one with a hose to a schrader valve. I use a small bicycle pump for pressure and a MityVac to pull a small vacuum. I made some plates to bolt over the exhaust studs with an O-ring, or if the pipe spigots are in I use some expanding rubber plugs from a pool store.

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tacky1
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Re: How To build A Leak Down Tester then test it on your 2 S

#4 Post by tacky1 » Tue Feb 07, 2017 11:50 pm

This is what I use....


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1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

LC Cnd
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Re: How To build A Leak Down Tester then test it on your 2 S

#5 Post by LC Cnd » Wed Feb 08, 2017 2:17 am

Russ where did you find the gauge and Tacky what are the aluminum bits - they look like caps for a super sized pint pocket metal flask. Like the exhaust flange cover idea way better than corking it.

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Re: How To build A Leak Down Tester then test it on your 2 S

#6 Post by tacky1 » Wed Feb 08, 2017 3:49 am

Its a kit I bought, They are solid plugs he machined out of solid bar, I had an old leak tester I used for years, It wasn't very accurate, But it held pressure and I could tell if a motor had a leak.
I treated myself to this kit,

Bought it from Nik over at 2t labs, Great guy, http://www.ebay.com/itm/Yamaha-Tzr250-T ... SwuhhXVuX0" onclick="window.open(this.href);return false;
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

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kpke
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Re: How To build A Leak Down Tester then test it on your 2 S

#7 Post by kpke » Wed Feb 08, 2017 11:51 am

I am poor so…

Expandable freeze plugs from the auto parts store for the exhaust ports. I don’t remember what size, 1 ½ inch or 1 5/8 inch or???

PVC pipe fittings for the intake rubbers.

A Schrader valve into a brass fitting that houses a low-pressure gauge that the PG&E guy left at my house when checking for leaks at the meter. Thank you sir. :smt045

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two-stroke-brit
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Re: How To build A Leak Down Tester then test it on your 2 S

#8 Post by two-stroke-brit » Wed Feb 08, 2017 2:47 pm

ken
Last edited by two-stroke-brit on Wed Feb 08, 2017 2:49 pm, edited 1 time in total.
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

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two-stroke-brit
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Re: How To build A Leak Down Tester then test it on your 2 S

#9 Post by two-stroke-brit » Wed Feb 08, 2017 2:47 pm

kpke wrote:I am poor so…

Expandable freeze plugs from the auto parts store for the exhaust ports. I don’t remember what size, 1 ½ inch or 1 5/8 inch or???

PVC pipe fittings for the intake rubbers.

A Schrader valve into a brass fitting that houses a low-pressure gauge that the PG&E guy left at my house when checking for leaks at the meter. Thank you sir. :smt045

Image

ken how do you keep the reed valves open so you are testing the whole motor and not getting a false reading from the closed reeds.
thanks mark.
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

RuZty
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Re: How To build A Leak Down Tester then test it on your 2 S

#10 Post by RuZty » Wed Feb 08, 2017 9:39 pm

LC Cnd wrote:Russ where did you find the gauge and Tacky what are the aluminum bits - they look like caps for a super sized pint pocket metal flask. Like the exhaust flange cover idea way better than corking it.
I found it on a shelf in a building that was about to be demolished at my last job, knew what I could use it for right away. I scored a hydraulic lift table big enough for a bike from there too.
The rubber plugs are easier than bolting up the flange and save removing the exhaust spigots if you have chambers on the bike. They would probably work in the ports too but I haven't tried.

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kpke
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Re: How To build A Leak Down Tester then test it on your 2 S

#11 Post by kpke » Wed Feb 08, 2017 10:50 pm

two-stroke-brit wrote:
ken how do you keep the reed valves open so you are testing the whole motor and not getting a false reading from the closed reeds.
thanks mark.
I think I stuck tie wraps in there. I'm not so sure it really needs it tho. Do they really seal that good?

LC Cnd
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Re: How To build A Leak Down Tester then test it on your 2 S

#12 Post by LC Cnd » Wed Feb 08, 2017 11:12 pm

About the reeds, bit of hassle but would't you just remove them? 2ndly, what is the maximum PSI range required for a proper test 8-10?
Last edited by LC Cnd on Thu Feb 09, 2017 1:43 am, edited 1 time in total.

tacky1
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Re: How To build A Leak Down Tester then test it on your 2 S

#13 Post by tacky1 » Thu Feb 09, 2017 12:11 am

I pop Tie warps in the reeds just to be sure, They leak back anyways, they are not 1000% sealed, I always test at 7psi..
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

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South_Oz
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Re: How To build A Leak Down Tester then test it on your 2 S

#14 Post by South_Oz » Thu Feb 09, 2017 3:03 am

Reeds are one way and you would be lucky to get them to seal against a low pressure- volume.

Ive never bothered holding them open.

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Re: How To build A Leak Down Tester then test it on your 2 S

#15 Post by RuZty » Thu Feb 09, 2017 11:52 am

Think about it. You are putting air in through the intake, so it has to go through the reeds to pressurize the engine. Even if the reeds did seal perfectly in static conditions (doubtful) and you had a leak on the intake side it would show on the gauge. If you had a leak on the engine side you would create a pressure differential across the reeds and they would allow flow into the cylinder from the intake as they are intended to, and it would show on the gauge.

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