Well everyone was right, I have an air leak that must be causing my high idle on my 01 blaster. Made my leak down tester today and tested. The bottom half of motor where the two halves come together on the top side is where it is leaking. Its leaking so bad you can hear it!! Also, small leak where the reeds bolt on intake. So where to start. Ive rebuilt a top end before on a polaris trailblazer, so I don't mind getting my hands dirty. Do I need a complete gasket set for everything, or how hard is that gasket to replace?? Any help is greatly appreciated!!!
Found my air leak! Now what????
- Thread starter quepasa69
- Start date
there is no gasket for the case halves where your main leak is at. you will probably have to split the cases to fix that. i did fix a leak there once by using compressed air to blow sealant in to the leaking area from the outside. i did it over and over until i thought it had gotten in there. then i roughed up the area with some 80grit sand paper and put some jb weld over the area.(only problem with this is you have to get that stuff off when you need to get back into the bottom end. Pain in the ass! the reed cage leak could be fixed with some yamabond or copper atv. hope this helps. you could replace the reed cage gasket but you still might have to seal it. great job findin the leaks!
if its leaking at the case halves, you need to split the cases, clean and reseal with yamabond. your going to need a clutch cover gasket, a base gasket and reed gaskets.
Then there are the 'might as well's' as long as the cases are split, new main bearings and seals aent a bad idea...
Then there are the 'might as well's' as long as the cases are split, new main bearings and seals aent a bad idea...
that gasket is simple to replace, just unbolt intake(since you need to reseal it also) exhaust, which you prolly already have off to leak test it, then the head, and cylider, i'd normally say just get a top end gasket set, but we've been seeing alot of aftermarket base gaskets leak, and recommend factory yamaha gasket for there,
so i'd just get a new one from the dealer, and a new head and intake gaskets too,
also be sure to get all the old gasket off the base and bottom of the cylinder, and dont be gouging sh*t, use some brake or carb cleaner to soften it up, and gently scrape it all off, dont let any fall into the bottom end, stuff a rag around the rod while doing it
be sure to use some 2stroke oil as lube on the piston and rings and get them rings back on the pins when dropping the cylinder back on
and let us know if that is an aftermarket green colored base gasket that leaked
so i'd just get a new one from the dealer, and a new head and intake gaskets too,
also be sure to get all the old gasket off the base and bottom of the cylinder, and dont be gouging sh*t, use some brake or carb cleaner to soften it up, and gently scrape it all off, dont let any fall into the bottom end, stuff a rag around the rod while doing it
be sure to use some 2stroke oil as lube on the piston and rings and get them rings back on the pins when dropping the cylinder back on
and let us know if that is an aftermarket green colored base gasket that leaked
findong the leak is the most important part, now just take your time and dont screw up, and just to clear things up, if your go the copper seal it is copper"rtv" not atv as scot said, simple mistake 
just making sure you dont get confused, and not smart @$$in scot
just making sure you dont get confused, and not smart @$$in scot oh, he's talkin case halves, dont forget the $100+ specialty tools needed to do this, flywheeel puller, 2 jaw puller, crank puller, and clutch/flywheel holding pliers.
i found it cheaper to tear the top end off and let a shop do the bottom the first time, but have since bought the tools
where you located, maybe another member can help/loan you the tools
and it helps to have the blaster manual while doing this, click the link at the bottom of my sig, i have it linked in there
i found it cheaper to tear the top end off and let a shop do the bottom the first time, but have since bought the tools
where you located, maybe another member can help/loan you the tools
and it helps to have the blaster manual while doing this, click the link at the bottom of my sig, i have it linked in there
well I am planning on going to waynoka ok at the little sahara in 2 weeks, so I might get the reed gasket and try jb welding case halves right now, and then this winter might make a good time to tear it down. Ive only owned this for a couple months and been fighting this out of control reving ever since. Would like to get one more good ride in before it gets really cold. If I tear it down I want to make sure and get all the right gaskets and do it right!
good call awk, forgot about the tools, i plan on slowly investing in all of the tools slowly so when something goes wrong i wount need to buy them all at the same time, if there is someone near you with the tools i am certain they would help out as much as possible
Quick question. The hose that comes off the tranny area where those halves go together, looks like a vent??? It runs up by handle bars and just ends there open. I did plug this off during leak test. Is this definately a vent, or does it need plugged off for good???
you shouldn't plug that for a leakdown. it is in the transmition which is not connected in any way to the area that you are doing a leakdown test on. the two areas(transmition and crank chamber are sealed off from each other. the tube is a good place to put soap to see if air is leaking into the transmition from the crank chamber. yes it is a vent and should be open durring opperation.
the same problem. you are leaking between the case halves. they defanitely need to be split and sealed with some yamabond. and a gasket kit is in order. might as well get an oilseal and gasket kit. but like awk said i would make sure the base gasket you get is an oem one.(an acctual yamaha gasket) the rest can be aftermarket.
dude, if your case halves are leaking externally, and now you say it's leaking out the vent, which means its leaking between the bottom end and the tranny, you needa get that fixed, asap, or you better take a tow strap with you to little sahara, your gonna be sucking air, fry a piston, and then be on here askin for ken oconnors number
/\/\/\ yes, but sounds like you needa click this link.........
Ken OConnor Racing, High Performance Motocross Engines, Performance Modifications, Motorcycle valve jobs, Motorcycle Crankshaft Rebuilds, Motocross Cylinder Porting, Motocross Cylinder Head Porting
or get that topend tore off and get the bottom to a local shop asap
Ken OConnor Racing, High Performance Motocross Engines, Performance Modifications, Motorcycle valve jobs, Motorcycle Crankshaft Rebuilds, Motocross Cylinder Porting, Motocross Cylinder Head Porting
or get that topend tore off and get the bottom to a local shop asap
Lapping is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.
This can take two forms. The first type of lapping (traditionally called grinding), typically involves rubbing a brittle material such as glass against a surface such as iron or glass itself (also known as the "lap" or grinding tool) with an abrasive such as aluminum oxide, jeweller's rouge, optician's rouge, emery, silicon carbide, diamond, etc., in between them. This produces microscopic conchoidal fractures as the abrasive rolls about between the two surfaces and removes material from both.
The other form of lapping involves a softer material such as pitch or a ceramic for the lap, which is "charged" with the abrasive. The lap is then used to cut a harder material—the workpiece. The abrasive embeds within the softer material which holds it and permits it to score across and cut the harder material. Taken to the finer limit, this will produce a polished surface such as with a polishing cloth on an automobile, or a polishing cloth or polishing pitch upon glass or steel.
Taken to the ultimate limit, with the aid of accurate interferometry and specialized polishing machines or skilled hand polishing, lensmakers can produce surfaces that are flat to better than 30 nanometers. This is one twentieth of the wavelength of light from the commonly used 632.8 nm helium neon laser light source. Surfaces this flat can be molecularly bonded (optically contacted) by bringing them together under the right conditions. (This is not the same as the wringing effect of Johansson blocks, although it is similar).
This can take two forms. The first type of lapping (traditionally called grinding), typically involves rubbing a brittle material such as glass against a surface such as iron or glass itself (also known as the "lap" or grinding tool) with an abrasive such as aluminum oxide, jeweller's rouge, optician's rouge, emery, silicon carbide, diamond, etc., in between them. This produces microscopic conchoidal fractures as the abrasive rolls about between the two surfaces and removes material from both.
The other form of lapping involves a softer material such as pitch or a ceramic for the lap, which is "charged" with the abrasive. The lap is then used to cut a harder material—the workpiece. The abrasive embeds within the softer material which holds it and permits it to score across and cut the harder material. Taken to the finer limit, this will produce a polished surface such as with a polishing cloth on an automobile, or a polishing cloth or polishing pitch upon glass or steel.
Taken to the ultimate limit, with the aid of accurate interferometry and specialized polishing machines or skilled hand polishing, lensmakers can produce surfaces that are flat to better than 30 nanometers. This is one twentieth of the wavelength of light from the commonly used 632.8 nm helium neon laser light source. Surfaces this flat can be molecularly bonded (optically contacted) by bringing them together under the right conditions. (This is not the same as the wringing effect of Johansson blocks, although it is similar).
did u just wiki that? i googled it and didnt find much. i have herd of lapping valves but not cases. i put mine together without sealand to see how flush they were and they werent so i used plenty of yamaha bond and made sure to tighten the screws around the crank 1st because those are the most crutial.. hopefully it works. thanks!
