Gearbox oil being drawn in and burnt so smokier than . Sometimes it wont run at all, other times it will race away. live with the start-up smoke, until you need to rebuild the engine. The clutch side is harder to tell because there is oil on the clutch side. The process of replacing valve seals involves disassembling, The entire engine until you can reach the valve spring. Why would these seals need If its out if true, balance, runout is out of spec, bearings in the crank are bad, it has tons of hours and is assumed bad, etc. Remove the cylinder head cover, the spark plugs, pushrods, and rocker arms. If you get fuel droplets spitting out of the front of the carb at idle.that's a good sign of a broken reed. Remove the pipe from the cylinder to look at the condition of the rings or seal. On 2 stroke dirt bikes, there is a rubber seal on either side of the crankshaft. Once this fuel air mixture has been sealed off by the reed . The first thing to look for is brass shavings in the lowest oil hose under the carbureator. other hand retarding ignition timing will allow the engine to rev higher and. One is to prevent dirt and oil from entering the lower end of the crank and the other is to prevent the blowing out of the compressed intake charge. EZGO Gas 2 Stroke . What came out was rather dark & dirty looking. Model of your vehicle. Gearbox oil has a very distinctive smell when it burns so it is easy to tell it apart from the two-stroke smell. If you find that your 2-stroke engine is leaking, it is likely due to the seals or O-rings. If you find this problem, suspect the main bearing seals. You know, $250 for a rebuilt crank is not a bad thing. Other than the smoke. Pull out the dipstick and try burning the oil on the dipstick with a match; If the oil on the dipstick spatters, there is water in the engine oil. Some bikes you can replace it from the outside, some you have to replace from the inside which sucks cause you have to split the cases to do it. Then it starts all over. Small leaks can cause oil to accumulate on the undersides of the engine, while larger ones may produce a drip of oil from the front of the engine. Sep 19, 2010. Only show this user. It all depends on the size of the leak. but as Robert mentioned, they are suppose to remover liquid gas/oil from the crankcase to keep it from building up. InfiniteMiles. The SRIS and CCI injection system both have valves and theoretically won't leak, but you can . On 2 stroke dirt bikes, there is a rubber seal on either side of the crankshaft. . Does it pop and fart out the carb like a burnt intake valve on a 4 stroke? * VISUALLY EXPLAINED * Efficient Understanding!Uniquely explained like never before, this video will give you a firm understanding of how this system works. Oil leaks Oil leaks are the most common symptom of a problem with the crankshaft seal. hard starting,backfiring,blowing crank seals out,damaging recirc valves&hoses.while most of these symptoms have more todo with older/smaller engines,any reed damage can give these type . I decided to flush out the RV case. Once you've found a leak, fix it and retest. Carburetor choke: Choke Lever down if engine is cold, if hot; choke lever up. It could be timing, it could be an oil seal, the pistons rings, it could be carb or intake related, or it could be your oil pump if you have one. A crankcase air leak is a problem many pro saw engines have at some point in their life. Unlike all 4 cycle engines, the two cycle engines in all two-stroke engines must have a completely air tight lower end. The BEST sign that your seals are gone is failure of a leakdown test. #1. Dirty oil gradually drips down through the foam cowling liner and onto the swivel tube/tilt bracket area. Locate the joint between the cylinder head and the cylinder block. Most technicians will suspect a problem with the reed valves only after they have exhausted all other potential problems. I've checked closely and excluded other possibilities like the oil lines/fittings and . The only way to tell is to look for other signs or to go through the problems one by one, I'm in the same boat as you right now and it sucks. I have always been curious how a bad reed valve reacts to a two stroke engine? If it passes a pressure test, apply a vacuum. 1. Go. Quote. Ask the customer to hit the unlock button 2 times on the remote, make sure the tether is plugged in correctly before you try any troubleshooting if the customer has 2 of the same bikes. A plug is inserted into the intake manifold and another plug or block off plate is used on the exhaust to create an airtight cavity. incorrect. advanced. With that said, here are the most common symptoms of a blown 2 stroke engine: Engine seized (won't crank over) Bike won't start Starts but doesn't want to stay running Power is significantly less Fouled spark plug This CR85 engine is locked up but I'll have to tear it down to figure out why S. I had that same problem on my shee when i bought it. Head gasket failure. Oil leaks are the most common symptom of a problem with the crankshaft seal. Remember that cranks seals have 2 sealing surfaces. Your idle will hang and/or the bike will rev erratic randomly. Regular use of additives such as Quickleen, Techron, Ring-Free, etc help to keep the ring lands clean and carbon free. Reed valves are used in many two-cycle engines, including motorcycles, snowmobiles, and lawnmowers. The fuel air mixture screws on the side of the carburettor are marked H for High for the engines high speed adjustments and the L means Low for the engines low speed adjustments. To check them on the ignition side is easy, just pop off the flywheel and ignition stuff and see if there is dust or dirt accumulating on the crank and the case near the seal. When the piston rings becomes old or damaged then the oil from the engine will start leaking into the combustion chamber, this leaking of oil will start burning and producing and thick grey and white smoke from the engine of your dirt bike. Piston skirt seizure in the cylinder. If its bad it can run very lean and potentially seize. That will tell you if the pump is good or not. So, clutch side crank seal must have gone. 00:00. That's the static part that seals against the crankcase housing so that can also leak. On the. Symptoms of bad crank seals GT380? Burning Oil. Symptoms of a Blown Head Gasket. How to do a leak down test on a 2 stroke dirt bike with a homemade tester. To ease your mind get the engine pressure tested and buy a clutch puller for future. You need to look at it and feel for a gritty feel in the bearings. Labyrinth seal failure symptoms. Logic being that the diesel would flush the bearings, soften the seals and also soften any rusting on the seal faces. 00:00 00:00. Low octane fuel. Location. If it is. Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment. The cost of this replacement job will be between $900 and $1,800, depending on the make and. CDI unit faulty. Nov 23, 2007. I decided to flush out the RV case. In the end it was engine out and stripped .The owner had a fresh crank fitted a couple of weeks before and it turned out the new labrinth seal was under size .Once sorted all was well. A leaky seal on the other side will lean out the air fuel mixture causing pinging and loss of power. The valve can only go in one way unless you modify it or damage (not likely) it. Pumped up to 6psi again and sprayed the seal with detergent. 3000 miles on the bike still starts easy and runs . (856) 785 9455. Grrrrrrr. Reed valves going bad can be difficult to diagnose as the symptoms can often be mistaken for problems. Next Last. 3:51 PM - Jan 31. . Brought to you by Barnacle Bill's Marine Supply. Nov 16, 2010. Wrong. Written by Teddy Henderson in Two Stroke If you're noticing a strange smell coming from your 2-stroke or experiencing an issue with it revving up, it might be time to replace the crank seals. Its doing everything a four stroke does, just does it using two strokes or cycles. One of the most common traditional symptoms of low compression is the smell -- and possibly smoke -- of burning oil coming out of your exhaust. And then this one that's inside here is lower down and seals on the drive shaft. CDI unit trouble. Moderator. top dead center (factory setting) there should't be any need to advance. Carefully look down the side of the cylinder block until you see a very fine and straight "crack" that runs completely around the block. What I did was hook up a vacuum pump to the RV oil return line to the tank. Symptoms include: over reving, overheating, stalling on acceleration, failure to idle, and worst of all, an engine seizure if the problem is neglected. I've checked closely and excluded other possibilities like the oil lines/fittings and . If this symptom shows up in conjunction with one of the other symptoms, a compression check is definitely in order. Small leaks can cause oil to accumulate on the undersides of the engine, while larger ones may produce a drip of oil from the front of the engine. The first thing to check before anything else is the mixture screws. if the clutch cable goes into the area under the ignition cover, there will be an oil seal which seals the clutch actuator arm shaft from leaking gear case oil inside the ignition cover and this seal's condition can be evaluated by visually looking for any signs of oil seepage or leakage which would need to be addressed before riding the dirt I pretty certain I have an oil leak from the bottom crankcase seal (s) on my 2007 115HP. A faulty or . A good test is also to rev it out of the water. The Theory of Air-leaks. Those seals can not be changed by a home mechanic. Posts: 19,285. I pretty certain I have an oil leak from the bottom crankcase seal (s) on my 2007 115HP. No problems there, Both of them held just under 2 pounds of pressure with zero loss in 24 hours. The SRIS and CCI injection system both have valves and theoretically won't leak, but you can . Started by pulling the engine out and having a good look around and a clean. A four stroke is leak down tested at 100psi and a 2 stroke at 6-10psi. sledcrusher said: dodgetruck2 said: i would think a bad crank seal would cause to low of idle, because the lack of presure and fuel that should stay inside the engine but is bein leak through the seal. Check spark plug; Replace if black and worn electrode is found. No Engine Start. If the seal on this side goes bad, you'll get air leaks. Do not pressurize the bottom end more than about 10psi or is will turn the seals inside out. I believe on the 400 that the impulse runs off of the pto side. If no start go to step #3. Strong smell of fuel in side cases. Dry running damage. Mixture Screws. More air means higher idle. Excessive carbon buildup behind the . A 2-stroke engine requires a properly sealed block to run right because it uses the crankcase vacuum created from the rising piston to pull the incoming charge into the crankcase; the downward stroke of the piston pressurizes the charge, pushing it into the . The cylinder head is the metal "cap" on top of the engine and is recognizable because the spark plug (s) protrude through this piece. M. MajorMotion New Member. Last active. Alan H wrote:Never checked the seals on my 550 resto some time ago, but took the top off and filled all three crankcases with diesel, then kept turning the engine over steadily over a period of a few days.Drained and repeated. Spark plug not correct. It's basically a metal disk that has the purose of sealing the crankcase during the downward stroke of the piston. If the crank seal on the primary side fails you will get transmission oil coming into the bottom of the crank and get a smokey exhaust and a fairly distinct smell of burning tranny fluid. Engine performance issues. So, it was definitely looking like crank seals were the culprit. Over time these dry out. The seals between the cylinder and exhaust pipe are the most common place that exhaust leaks can occur. Originally Posted by bitzz Lousy idle, screams at top end, plugs show lean after screaming at top end. A small "air leak" at a crank seal or an intake gasket will cause the usually perfect fuel/air mixture in the crankcase to become slightly lean.sometimes very lean. midlifecrisisrd. The Pressure Test The step by step is : When we see smoke coming out from the exhaust is not a good sign in your dirt bike . The first thing to check before anything else is the mixture screws. This means oil got out and it could have only come out the crankcase. Triple Cranks. A four stroke is leak down tested at 100psi and a 2 stroke at 6-10psi. One example is a failing PTO bearing causing the seal to elongate and allow air to enter the crankcase leaning the fuel air mixture on that side eventually detonating the piston. I warmed it up on my lift, put it in 3rd gear and gave it some brake drag to replicate a modest load. the powerband will be shorter and the engine can not rev as high. Joined. #2. If there is any tattering, cracks, or abrasion to the O-ring, it . What I did was hook up a vacuum pump to the RV oil return line to the tank. Will a 2 stroke run with bad crank seals? Ignition timing . (856) 785 9455. If the RPMs hang up and dont drop right away its no bueno. If you had bad crank seals, the motor would puff LOTS of white smoke when it runs. This happens because the bad seals let transmission oil into the crankcase and it gets burned with the other gas. Bingo, did the leak down test with motor on the bench (could have done it in the bike but was sure its the seal leaking) with the clutch basket removed and the crank sprocket removed (clutch holder tool worth every cent) so you can see the seal. #3. The seal on the magneto side (left side) prevents air from getting into the combustion chamber. So the question is what are the symptoms of shot seals - guessing lack of power and running like a pig, guess it would also affect starting. The fuel air mixture screws on the side of the carburettor are marked H for High for the engines high speed adjustments and the L means Low for the engines low speed adjustments. Mixture Screws. Most of the time the story ends with a blown engine. Backfire, Blowing Crankcases Or Spitting: If you notice that your engine suddenly started backfiring or one carb started spitting more than standard, that is the earliest possible indication of bad reed valves. Symptoms vary but possibly; Hard to start. Step 1. If your crank seals are shot (like mine) - the drive shaft will have black soot all over - esp near the top.. pull the lower unit and inspect the drive shaft.. if the crank seals are gone ull prob see oily mucky water spitting out the mount seals as well.. a good sign those are shot too - No oil puking. When it comes to leaks, vacuum is just as important as pressure. So, it was definitely looking like crank seals were the culprit. No timing on a rotary valve. Location: Kansas City, Missouri. A typical sign indicating you need to replace a two-stroke crank seal is an oiled plug or oil dripping from the exhaust pipe. The two stroke actually has four things going on also 1. compressing the cylinder mixture while 2. drawing mixture into crankcase 3. blows (ign) the piston down while 4.transferring/savaging the mixture. When grey or white colored smoke comes out from the exhaust. Only show this user. Dirty oil gradually drips down through the foam cowling liner and onto the swivel tube/tilt bracket area. Knocking: Carbon built up in combustion chamber or on piston crown. Bad Piston rings shown some signs of which we are going to explain:-. Some engines will hold 6 - 8 lbs pressure, but not be able to hold a vacuum. This would be a sign that the brass gear is sheared off where it . Smoke coming out from your dirt bike exhaust is a obvious sign of something wrong. Overheating of the engine. Symptoms of bad crank seals GT380? Ignition timing not set properly. JS440. What came out was rather dark & dirty looking. Which way do crank seals go? Crank Seal Replacement on Stihl motor. gaz. Brought to you by Barnacle Bill's Marine Supply. A lot of guys have wrecked engines using hammers to get clutches off. Cracked and leaking lines will give the same symptoms as a bad crank seal. I replace all 4 on my C40 when changing out the crank, only 2 were bad, but I figured if 2 are bad the other 2 are not far behind. Proper ring seating and sealing is also critical to 2 stroke engine performance. Quote; Post by tz375 Wed Feb 17, 2016 9:17 pm. Quote; Post by tz375 Wed Feb 17, 2016 9:17 pm. Crankshaft bearing worn or damaged. There's an o-ring around the outside. If the seals are the same type that's in an Lc or pv, they have an outer rib going around them which means a crankcase split, but I'm not familiar with your bike - a microfiche pic will help you determine that. Re: 2 stroke crank seals, what r the signs.. Possible flooded engine: Try starting with throttle wide open. Jul 12, 2011. Crank Seals and Compression. 4 Symptoms Of A Bad Reed Valve: The symptoms of bad reed valves are usually similar to the below-explained indications: 1. A. No problems there, Both of them held just under 2 pounds of pressure with zero loss in 24 hours. If the crankshaft seal dries out, cracks, or breaks, it can cause an oil leak. is it running OK? Symptoms of a blown head gasket vary depending on how a gasket fails, but common signs include: Overheating. The oil hose connects to the side of the engine at the very bottom. A center crank seal will leak a little oil, into the engine, and cause it to smoke on start up. Bad crank seals will not affect compression, they do not leak fuel. A leak down test works by pressurizing the crankcase cavity and cylinder. Aug 2, 2005 Blown crank seals are usually a symptom of another problem. Spark plug. Overheating: Ignition problem: Spark plug fouled, broken, or misgapped. It is a 12mm hose ( almost 1/2 inch inside diameter ), not the smaller hoses. An often overlooked item on 2-stroke motorcycles is the crankshaft seal/s. Id think a bad crank is a pretty broad thing. If it is a BN carb the plastic cap for the fuel inlet will leak. Apr 26, 2021 at 2:40am via mobile. This leaking of smoke is not good for your engine. Check its not gearbox oil, its unlikely but worthy of being sure, Check it. 1. Beyond checking compression, carburetion and ignition, Brad says the single most important test to run on a 2-stroke is a leak-down test. Do not pressurize the bottom end more than about 10psi or is will turn the seals inside out. It could be timing, it could be an oil seal, the pistons rings, it could be carb or intake related, or it could be your oil pump if you have one. Re: What are the symptoms of a bad rotary. Click to expand. If the crankshaft seal dries out, cracks, or breaks, it can cause an oil leak. Thread starter MajorMotion; Start date Apr 7, 2020; 1; 2; Next. I was going to refresh the piston anyway at some stage so good chance to check it. A leaky crank seal could be allowing air or gearbox oil into places it doesn't belong and causing all kinds of issues. Check spark fire by laying spark plug with wire connected on engine head fins while . Here are 10 reasons and fixes to help prevent lack of fuel to a 2-stroke engine. Apr 7, 2020 #1 My question is will there still be good compression (140) with bad crank seals? A typical sign indicating you need to replace a two-stroke crank seal is an oiled plug or oil dripping from the exhaust pipe. A small air pump is used to pressurize the cavity to 5psi and the pressure is monitored in the cavity for around five minutes.