Search results for query: Crank seals

Hi, I recently bought a 1988 Yamaha Blaster that ran away on me, luckily I was able to stop it before it blew up. I took it apart, performed a leak down test, and identified the clutch side crank seal as the cause of the air leak. I removed the seal and installed a new one from Vito's...

When you pull the choke out it just uncovers a hole and allows more fuel to dribble in on the engine side of the carb. I would guess an air leak at the crank seals or youre running lean normally. Does it randomly idle up while its sitting?

...called a Schrader valve which this "cheap" one might not have? I honestly have no clue. Regardless though, it's either due to the crank seals being bad or this it's just natural due to it's 2 stroke nature and age. The actual question I have is regarding the operating temperature of the...

I appreciate all the help and replies. I replaced the crank with a new vitos stock crank. New seals again. I bought a cylinder and piston from Ken O'Connor Racing. Spoke to him and put a 330 main jet in. Did my leak down test, it passed. I'm happy to say it's been running great with over 10...

I will be taking the Blaster in to a local shop for a leak down test & a compression test on Monday. I haven't had great luck finding a mechanic that can get it in, get things tested & get me pointed in the right direction, regarding repairs. I have even looked at buying a complete, running...

First off it’s bone stock just like it came from the factory. I ended up with a 190 main jet and it’s running really good. The crank seals are easy to replace and the clutch cover gasket is cheap on eBay. Being that everything on my bike is original I’m slowly replacing all the gaskets and wear...

Well messed with jetting all day then decided to do a leak down test. Went to Home Depot and spent $18 on a gauge and some pvc pipe fittings. Then to the hardware store for a rubber plug. Got home and grabbed my bike pump and instantly found a huge leak from the stator side crank seal. Hopped...

A leak down test is actually where i would be starting. Almost sounds like you are running lean even though you upped your main jet. Leak down test is checking for air leaks that may be causing the lean condition, i.e. your engine is sucking in unregulated air than the carb can handle. Super...

So the crank seals is that something I can do when I have the top end off?

...carb can allow unregulated air in causing a lean condition. This would include the carb boot, reedvalve gaskets, cylinder base gasket, crank seals, crank case center gasket, and in some cases even a head gasket. But in the case of a badly leaking head gasket, most times you won't hardly be...

Crank seals are what gour outside the crankshaft bearings and seal the crank case keeping unregulated air out. With a 2-stroke, the fuel/oil/air mix is delivered into the engine crankcase during crankcase vacuum created by the piston moving up. Most of the 2-stroke oil falls out of suspension...

I thought so. On this one I just did a meticulous top end on it. What exactly are the crank seals? They sound intimidating..

With proper tuning, no air leaks, and good maintenance, a rebuilt 2-stroke should last many hours of operation. I don't remember exactly what you did to rebuild this engine, did you do crank seals?

Just put a new top end on my blaster (eBay kit) . I have plent of compression and spark is good. Carb is clean and clear with pod filter. Fuel is reaching the carb from the tank. Here’s where I’m confused: I poured some gas in the cylinder and it still didn’t fire!!! Possible crank seal??? Any...

How about if the port on the carb that used to be the oil supply was just a cut off hose would that be some of my problem? Just wondering.. I capped it anyways once I realized that's how it's supposed to be.

Crank seals, carb boot (dry rotted, cracked or just loose) cylinder base gasket and reed valve gaskets are the most common causes. Other less common cause could be a crack in the crankcase between the crankcase and transmission or other outside source of unregulated air can be taken in. But...

...Honestly, with a machine as old as the newest Blaster are getting, I would do a full rebuild, top to bottom. Crank and CB bearings, crank seals, possibly have the crank rebuilt, determine what bore the top end is on and get the cylinder bored and a new matching piston for a fresh clean slate.

...is apart, check float adjustment and adjust as necessary to Keihin factory spec. If all of this checks out check for engine air leaks. Crank seals, base gasket, and reedvalve gaskets are the most common causes of air leaks. Case center gasket can also but is less common. If the engine is...

Awesome information I certainly will thank you sir 👍🏻

...There can be quite a few different causes, most common with a 2-stroke would be a lean condition caused by an air leak. Base gasket, crank seals, reedvalve gaskets are the most common. Evidence of a lean burn-down with loss of compression would be in the form of the piston crown on the...