Suzuki Quadracer HQ
Suzuki Quadracer HQ Discussion => Suzuki Quadracer HQ - General Discussion => Topic started by: Derrik on October 09, 2012, 03:08:13 pm
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I found a cool low psi gauge at a local welding shop for 11bucks,gout the brass fitting hook uo a hose for 7 bucks,and got 4 ft of about 3 bucks.
there was also a schrader valve and the t fitting i got for about 8 bucks so hopefully i can find a way to hook it up and fill my cases to check for leaks after my rebuild.
i cant find the right size freeze plug the cap off the exhaust and i need ideas for how you guys hooked up the pump and or what you used.
worst case senario im going to have to cut out a special block off plate that bolts up to the intake and exhaust.hopeing to find a cheap/easier way.
also ideas for a cheap/effective compression tester.ive read that the harbor freight stuff tend to be inaccurate,and cause the gauge hose is bigger on the harbor gauge its better suited for v8's and not small displacement motorcycle engines.
whats you opinion and experience with this?
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i used a patch of rubber and screwed my pipe flange on to seal the exhaust.
you can pick up a valve stem at lowes to hook a basketball/foot pump too.
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Got the rubber plugs from Mcmaster carr http://www.mcmaster.com/#expansion-test-plugs/=jng2ls
Hole saw a metal or plastic plug at least 1/2" thick (my LT500 was 46mm or 1.812" 1- 13/16)")
Drill and tap Pipe Size 1/8", NPTF use a 1/8" fitting
(http://i192.photobucket.com/albums/z183/erbe03/Suzukiquadracerhq/100_1037.jpg)
(http://i192.photobucket.com/albums/z183/erbe03/Suzukiquadracerhq/100_1038.jpg)
(http://i192.photobucket.com/albums/z183/erbe03/Suzukiquadracerhq/100_1039.jpg)
Spark Plug Seals The Head
(http://i192.photobucket.com/albums/z183/erbe03/Suzukiquadracerhq/100_1040.jpg)
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that is dont nicely,guess i need to look up mc mastercarr!!
any one have an idea what freeze plug may work for a lt 250??
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Ok, so what exactly does the readings tell you? Ring issues, crank sealing issues?
Nice DIY tester Mitch!
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Ok, so what exactly does the readings tell you? Ring issues, crank sealing issues?
Nice DIY tester Mitch!
On engines that have power valves, it usually tells you that you need to figure out a way to keep the power valve from leaking air into the crankcase so that you get an accurate pressure and or vacuum test. :)
Once you solve the power valve sealing issue, a pressure test will help indicate leaking gaskets, cracks in the cases or cylinder and if the pressure lips on the crank seals are leaking. IT WILL NOT REVEAL IF THE CRANK SEAL SUCTION LIP IS LEAKING. Crank seals have two lips. One lip holds pressure and the other suction. The suction lip is the most important lip and the lip that is most apt to leak causing a lean condition at partial throttle. A vacuum test is also necessary to accurately test for leaking crank seals.
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Never seen the vacuum test procedure. I have a mighty vac, what's involved in the vacuum test?
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Dezsled, a hand held vacuum pump works well also ( Brake Bleeder Pump) http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html
Now you know why I told you about double O ringing the power valve.
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Yeah Mitch I'll be doing that double oring trick for sure...
Great tip
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double o-ring trick huh???
would you mind letting me in on this tidbit of info??
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lol.... this is tough one to explain let me see if I can ........ put two little green orings on powervalve shaft ......... between the bearing and pv under the limit plate.
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(http://www.imagessite.com/OEM_Images/Suzuki_atv_images/87LT500R3.gif)
Use (2) of the #8
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interesting,the green o-rings you are referring to are the ones commonly used in a/c systems?
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ok i cant ever remember how much air and how long does it have to hold air for.
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interesting,the green o-rings you are referring to are the ones commonly used in a/c systems?
Just OEM O-Rings, using 2 O-Rings is added insurance of not having any leaks around the power valve is all.
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5lbs
and if you still have 5lbs after 10 mins you're good.
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ok thanks, i just found it again
4lbs for 4 to 5 min, and you can lose 1/2lb in that time and it still ok.
does this sound right.
and who has the o-rings for sale. beside mmcar
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Suzuki. I think I have some extras.
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cool lmk Matt, and what do you have to do pull that bearing out of the power valve, is it behind it.
i just took mine apart and i didnt see it.
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Did it come on on the valve? If not, should be easily visible
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yeah i didnt see it, i really cant see it being behind that bearing tho
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ok thanks, i just found it again
4lbs for 4 to 5 min, and you can lose 1/2lb in that time and it still ok.
does this sound right.
and who has the o-rings for sale. beside mmcar
Personally, i'd never run a bike that has any kind of an air leak.
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Here is a pic with the 2 O Rings, almost room for a 3rd one
(http://i192.photobucket.com/albums/z183/erbe03/100_1108_zps74dda74a.jpg)
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AWESOME!!! im still waiting on finances to get mine together -_-
thanks for the info!!! this **** is priceless!!!errr well THIS **** SAVES ME MONEY!! lol
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JH, what Do you do to prevent the exhaust valve from leaking? Recommendations on how long a motor should hold air pressure?
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thanks for the pic mitch, now i am gonna go look at it again.
matt send me those o rings. lol
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I'll have to get to the shop and look for them. Give me a day or so.
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Matt lmk what i owe you, and can you get a few more sets of them. i might
as well have some spares. thanks
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JH, what Do you do to prevent the exhaust valve from leaking? Recommendations on how long a motor should hold air pressure?
I use a inflatable bladder that goes into the exhaust port upstream of the power valve. Checking engines with power valves is a real pain.
Pressure checking helps find leaks that are due to cracks and leaking gaskets. Pressure is not a good test for crank seals if you are experiencing a lean condition. A vacuum test is what is necessary to test the lip on the crank seal that controls leaks that cause a lean condition.
I generally use pressure and vacuum test for diagnostics before tear down not after rebuilding an engine. With enough experience, you learn where to look and correct the problem areas before assembly.
An air leak that is bad enough to cause a lean condition at and idle or high-RPM closed throttle deceleration will usually need to be around a 3 to 5 psi or more per minute leak. The TM 38 carburetors that are bored to more than 41.5 will usually have what is comparable to a leak that is much worse than a 3 to 5 psi air leak due to bad gasket or crank seal.
A small air leak will have little effect on the air fuel mixture at full throttle. Air leaks, worn out slide bores and overbored carbs cause the most problems at partial and closed throttle operation.
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How deep of a vacuum and how long should it hold? I have a 7 cfm vacuum pump and a micron guage, hoses, etc for hvac work.
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dang,so it looks like i need to build a vacuum setup now -_-
great info tho,im learning so much!!! :D
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ok so looks like i will need a vac tester now.
what is a good one to get, not looking to spend a bunch of money on one.
just need to test a motor maybe every year or so. will a brake bleeder
work good euough.
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I imagine that my hvac vacuum pump and micron gauge setup is overkill. We use these for pulling deeeep vacuum to evaporate any water molocules inside an AC system before we put refrigerant into it. What is probably necessary is a vacuum gauge used to test automotive vacuum systems... Something that measures in inches of water column.. Not microns.
If I hooked one of my pumps to a tight engine, it would probably damage the suction lip on the crank bearing seals.
Hopefully a builder on here can clear this up.
How many inches of vac. And for how long? I would like to know for my current rebuild.
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also more ideas on where to get these pumps and gauges at please =]
cheapest route possible!
i have to much money going out in parts -_-
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One option to consider when building a tester is that you don't have to install the hose barb on the intake plug.
Take an old spark plug and weld a 90 deg pipe thread elbow where the spark plug turns into steel (break all of the porcelain insulation off so it's a clear shot into the engine), then screw on a steel hose barb (or quick connect if you have a good air seal in there).
Install the stubby spark plug adapter, hook up hose, and plug the other openings.
A bonus to this method is that you can also use the same plug adapter for a compression tester.
I use a similar method for differential compression tests on my radial, except that I welded 9 plugs up by installing a quick connect on the ends of every one of them.
It's important to check compression while the engine is hot, and as you could imagine removing all 9 plugs, then installing and removing an adapter for each cylinder can cause the engine to cool off before you're done.
Had the same idea for my hybrid, but I realized that there would be clearance issues with the straight plug and hose so I welded mine up with a 90.
Works great with the limited clearance!
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would a brake vacuum tester be fine for doing the test. i found some that are pressuer tester and a vacuum tester.
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When I Pressure test an engine I use a sheet of rubber under the exhaust spigot with three holes punched for the ex studs and snug up the bolts. I have a aluminum bung I made for the carb side. I pressurize it with a harbor freight radiator tester and an adaptor I made for the spark plug. you can use anything to pressurize the cylinder, I use to use a old squeeze bulb and gauge from a blood pressure cup. just be sure the ports are open or it will take a minute to stabilize a reading if all the air has to pass the rings.
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so it crossed my mind a while ago but i figured i would ask a question that may be obvious to the seasoned builder.
since it is recommended to test an engine at "operating temp" so the operating clearances are achieved,do you just ride the bike and nascar pit crew the damn thing while its hot to install the plugs and pressure/vacume fitting so its as close to operating temp as possible?? or is the whole operating temp thing only important for compression checks?
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It's important for compression testing, the rings seal better when they're hot and a fresh coat of oil.
Leak down tests, I'd say it would give you more accurate data, since clearances, seals, and gaskets change dimensions with heat.
The problem is getting it set up for a leak down test while everything is hot, and completing the task before it gets cold.
Most everyone checks the engine cold with a pressure tester, but there is a way to test for leaks while the engine is idling.
Take some starting fluid and spray it over every possible sealing surface (gaskets, seals, etc.), individually, and being cautious about the possibility of a fire hazard.
Anyway, if there's a leak on the base gasket or reed cage, spraying starting fluid over the leak will cause the engine to run rich and sputter at a reduced RPM.
Usually only good for a quick troubleshoot, or if the problem only arises when the engine is hot.
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ive been using the chit out of that carb cleaner while idle method for years with cars and trucks to find vacuum leaks!!
thanks for the info
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I think 3 - 5 minutes. but if the motor is leaking, it will show immediately on air pressure (watch the gauge when inflating) but not more than 5 bar inflate otherwise you hit with the resulting pressure from the seals around your sleeves. then you can fully open the engine again. all the best Frank
D?
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Ok +k2
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This is a really nice guage, it also has a schrader valve. You can just use a bike pump, I made a tester for under $25.
http://www.ebay.com/itm/350311871137?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
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JH, what Do you use to prevent the exhaust valve from leaking? Recommendations on how long a motor should hold air pressure?
You can get a rubber bladder at a plumbing supply store that can be inserted into the exhaust port between the piston and power valve hole in the bottom of the port. The carbon will have to be removed from the port or the bladder may not seal when inflated.
Zero leakage is ideal but a few psi per minute will not usually cause enough of an air leak to cause the engine to run lean. Do not put over 10 psi into the crank case.
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What happens if you put in more than 10 p.s.i. Into the crankcase?
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What happens if you put in more than 10 p.s.i. Into the crankcase?
It could possibly push the crank seals out of the cases if the seal was not installed correctly or the crank seal bore is loose or damaged. The crank case can experience around 20 PSIG in a healthy highly developed two stroke.
A pressure check will show a leaking gasket or crack in the cases or cylinder. A pressure check will NOT always show a leaking crank seal. For a crank seal that has worn pressure lips, more pressure will make the seal lips grip the crank "tighter" and leak less.
There are two lips in a crank seal. One lip is made to hold pressure and the other lip is made to hold vacuum. If the pressure lip leaks, it just causes a slight loss in power. If the vacuum lip leaks it causes a lean condition and or it will suck oil from the transmission.
Pressure checking a two stroke engine will not usually tell you if the vacuum lip is holding or leaking. It is not usually necessary to pressure check an engine that has a leaking vacuum lip. The engine will exhibit lean symptoms by having the ring-ding-dings on deceleration, high RPM idle and or acts like it is running out of fuel. If the pilot jet is not restricted and the correct size, the engine probably has some type of air leak.
Engines that have experienced a broken piston skirt, often have damaged cases and will leak air. Engines that have had welding done on the cases will often leak air. Engines that have had a big end bearing failure will often have case damage and leak air.
Pressure checking an engine is a diagnostic tool that we seldom have to use. It will not hurt the engine but can be time consuming especially on the engines that have power valve systems.