Sounds like you have used old gas. Answer. How to Check the Left Crank Bearing And Crank Seal on A 2 Stroke Dirt Bike. 5 years ago. Crank seal replacement, behind the flywheel on a Stihl 2 stroke : How difficult is it…? A leaky seal on the other side will … Improper float height would cause the … I don't know where you're getting a 3cyl 2 stroke crank rebuilt for $250 maybe 3 times that to do it right. Check all the simple stuff before you tear apart your bottom end. Re: t500 bad crank oil seal, process? This happens because the bad seals let transmission oil into the crankcase and it gets burned with the other gas. 98 Indy 500 PTO crank seal test. Backfires while trying to start.....if it does start it misfires feels sluggish and smokes. A crankcase air leak is a problem many pro saw engines have at some point in their life. So far you description of problems doesn't sound like seals. minimal leakage to the outside of the engine. Cracked and leaking lines will give the same symptoms as a bad crank seal. A number of things can go wrong within the workings of a 2-stroke engine. Jan 6th 2016 at 2:17PM. As they rise and hit the top of the piston, harmful gases can now pass underneath them and travel down, eventually making their way into the crank case. How do to tell if the crank shaft is bad on a 2 stroke dirt bike? Expert doesn't sound very expert. It was damaged badly trying to remove it so I couldn't compare it to the new one. The new one appears to seal a lot better to the crank visually though. This is good for main bearing lubrication because the bearing is running in oil. Another way in which blow-by can occur is by the gases passing through the piston ring gap itself. Mercury master technician. The symptoms are classic: You fire up your bike early on Sunday morning, and take it out for a warm-up ride. After using a outboard motor, unplug the gas line and run the motor until … Some of the above symptoms are lean, your pop off could also be too high. Still, if you're going to repair the center seal, you should take the time to find out where your small leak(s) are occurring, thru the tranny, or side seals using the soapy water spray method. 1 0. then after 5 mins of being stopped it wont start. Anyway,the only seal that would vent into the trans would be the RH side behind the clutch cover which can be replaced without total teardown on most bikes.But... that seal would more likely suck the trans fluid into the lower end of the R cyl and cause that cyl to smoke like hell. Symptoms of bad crank seals GT380? Symptoms include: over reving, overheating, stalling on acceleration, failure to idle, and worst of all, an engine seizure if the problem is neglected. If not tight the cylinder will not fill/exhaust properly which will lead to reduced perfomance and other running related issues.

Strange, however, that no oil or fuel is visible as the crancase pressure would force a little amount out if the seal is not tight? - filling the crank case with fluid wont do anything unless you have a complete seal failure, and in which case it real obvious - the saw will not start or if it does, wont idle. 27 cc Was using it last week, started up as normal to blow the grass clippings off the driveway, set it down to move some lawn furniture,,, picked it back up and I had no high RPM’s… it idled but wouldn’t rev. Anonymous. Re: Lower Crankshaft seal bad?? With Engine warmed up spray carb cleaner on PTO seal. Any input good bad or otherwise will be greatly appreciated. Replacing 2-stroke engine Crankshaft Seals An often overlooked item on 2-stroke motorcycles is the crankshaft seal/s. I had that same problem on my shee when i bought it. Can the seal be removed and a new one installed with out dorking anything up? ... fully accept that I should have done but as the crank did not look that bad, or the inside of the cases I thought I would give it a shot on the understanding that I may well have to pull it all down again. I know its a two stroke, cause of the 32:1 comment. You might have cack in your carbs. However, with the proper maintenance and diagnostic ability, many of these issues can be prevented. Seals are often great on pressure, but just fail under vacuum. In fact, the hard-to-reach location of the rear main seal goes to show how this part of the vehicle was never really intended to be replaced during the span of the car’s ownership. If you have a bad crank seal on the right side, it will be spraying oil out the right side exhaust pretty bad. If the crank seal is bad on the transmission side ( which I think is what you are asking ) transmission oil will be sucked into the crankcase and burned. Source(s): Me. Crank seals in two strokes can wear and start to leak, creating problems. ... or reed cage, blown crank seals, or any bad gaskets in the top end. On a 2-stroke the crancase is a part of the air/fuel mix flow's way to the combustion chamber. That would cause the exhaust to smoke heavily and foul . ... A four stroke is leak down tested at 100psi and a 2 stroke at 6-10psi. Running on out the water is a classic crank case leak symptom, but you dont say it does this, so i would look at your carbs first. Asked by Wiki User. It's bad because to change the seal you have to split the crankcases and pull the bearing. Oil leaks. Symptoms of a Bad or Failing Crankshaft Seal. ProX put together a list of 12 key things to keep your 2-stroke running strong. Assuming a normal seal, yours is apparently leaking and bad. The old seal looked like it wasn't sealed completely to the shaft and had oily residue all under the flywheel. 1,019 85 2. Hi. This should be obvious as the bike will be producing loads of smoke even when properly warmed up, and the oil level in the transmission will noticably reduce. If you had bad crank seals, the motor would puff LOTS of white smoke when it runs. If a crank seal is leaking it can allow gearbox oil to enter the crankcase and causes the bike to run rich. Mag seals leak for a number of reasons; if the crank twists and gets out of true it will ruin a seal in a hurry. YourMechanic. remove engine? Top Answer. I spoke to a few people who said they had this same problem and it was the result of bad crank seals. If the crankshaft seal dries out, cracks, or breaks, it can cause an oil leak. Troubleshooting An Air Leak. Servicing the crankshaft seal according to the recommended service interval can prevent the seal from failing in the first place, which can cause other problems. Wiki User Answered . Post by PippiFyrecracker » Fri Apr 24, 2015 2:16 am yes that was happening, but that would also be the same symptoms for any of the crank seals no? 2010-03-09 18:04:02 2010-03-09 18:04:02. Checking the condition of a 2 stroke dirt bike's LH crank bearing and crank seal is something that should be done occasionally and this is true whether riding motocross, off-road disciplines or FMX. The right side crank seal. Andy_C. the spark plug. Your description sounds like only the center seal is bad, i.e. Symptons are awkward..... tempramental on rare occasions it starts first or second kick and ticks over for 15 mins or so. Symptoms of a Front Crankshaft Seal Leak When a front crankshaft seal fails you will have an oil leak The front crankshaft seal located in the front of your car's engine and is designed to hold oil from leaking as the engine is running and the crankshaft is turning. First of all what bike? 2smoke250 # On your intake stroke which occurs after your exhaust stroke, the pistons will then move up. Oil leaks are the most common symptom of a problem with the crankshaft seal. Also check your compression. A typical sign indicating you need to replace a two-stroke crank seal is an oiled plug or oil dripping from the exhaust pipe. 1 2 3. Located on either end of the crankshaft, their task on one side is to provide a seal between the gearbox and crankcase and on the other side a seal between the atmosphere and the crankcase. Rear main seal leak symptoms The issue can be hard to identify because the parts in question are relatively unknown to most car owners. would mix with the gas. I dont think they do have ribs around seals. Do not pressurize the bottom end more than about 10psi or is will turn the seals inside out. So the big question is after I drain everything, and remove what needs to be removed to get to the seal. Engine will stall. 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. Quote; Post by hahahaurugly » Tue Feb 09, 2016 10:10 am. Of course most of the engines that are designed this way are race engines and the seal is easily replaced when you have the crank out for regular maintenance. If the right crankshaft seal was leaking, crankcase oil . This is my Leaf blower – StihlSH 86 C . Crank Seal failure symptoms Crank Seal failure symptoms. Share; 0 Comments; The crankshaft seal is the seal located …