INVADER 340 OVER OILING

[IraqvetUSMC]

That's not to far from me. I live in lowell, the town just south of crown point. Are their any signs that I could look for for the crank seals being bad? With a baby and all I am not sure if I will have the time this summer to tear out the engine. I would like to get the carbs cleaned and rebuilt atleast and check the check valves for my over oil issue. I work a lot so bit much free time here lol.

[rminier]

....crank seals...yeah, you can rig up some rubber gasket material to fit between the exhaust y-pipe and the motor, and do the same on the intake side by putting a solid rubber gasket between the carb boots and the motor to seal up the motor completely. Then you can put air pressure to the innards of the motor...up to only 5 or 6 psi....and see if the pressure holds for a couple minutes. But it's almost certain that those seals are pretty "iffy" and you risk sucking air through one of them and seizing a piston.
  Probably as important to the sled running reliably as cleaning the carbs and putting gas in the tank.
  But, look at the bright side, if you replace them now, the crank seals should be good for several years.

[IraqvetUSMC]

I definitely know what you mean about just getting them changed now and being done with it, id really hate to run lean & burn up a piston. Realistically how long should it take to pull the engine, r&r seals & reinstall?

[rminier]

  IDEALLY, if you had a compression tester, you could check to see if both cylinders had compression within 10 percent (or less)of each other, then you could assume the pistons and cylinders are in pretty good shape. If it ran pretty well during the time you got to ride it last winter, they are probably good to go. IDEALLY, you could install 2 new pistons while the motor is out, but that's gonna add $100 bucks to the project and another 3 or 4 hours time.
  Removing the motor for the 1st time, allow a couple hours. Then, the battle to remove the flywheel begins.
  If your pistons and cylinders are OK, and you are just replacing the crank seals, you can lay the motor on a workbench with the cylinder heads down. Then you can just remove the the bolts from the bottom of the motor that hold the crankcase halves together. Then you can get to the crankshaft with the seals on each end. There is a pressed on gear on one end of the crank that you gotta remove to replace the seal on that end.
  You have to clean everything up well, particularly the two mating halves of the crankcase, which will get sealed back together with some Yamabond or ThreeBond 1184 sealant....don't use regular silicone. I'm sure if you entered "crankcase sealant" in the search part of this site, you will find some other good sealants.....I can't remember their names. I have always used the ThreeBond stuff, with good luck. It used to be called ThreeBond 1194, but the new, environmentally friendlier formula  is now called 1184.
  All told, it would be a pretty good 8 hour day for someone that is doing it the first time. And that's if you don't have to fight too long removing the drive clutch, the flywheel, or the crankshaft gear.
  But, break it up into segments. Remove the motor one day. Tear it apart to change the seals  another, and install it whenever you get a couple hours.....
  Take your time...you will probably have questions as you work through this.

[rminier]

  Another good thing, once the motor is out, the carbs are removed, the exhaust y-pipe is removed...you can look into the intake and exhaust ports and see the pistons and parts of the cylinders. You can tell if they are all scuffed up, or still look pretty good.
 

[rminier]

  OR...if you have a way to haul the Invader....plan a trip to Delphi sometime this summer. I have 4 WEEKS vacation saved up....I intend to take 1 in late May, 1 in June, one in July...another....whenever.. .
  I have everything on hand to tear into this.
 I plan on spending LOTTSA time on the lake with my kids and the boat and jet skis....but I would be happy to spend a day helpin'.... .
  The only out of pocket cost, other than the new crank seals, and the gas to get here and back, would be (most importantly) a cold 12 pack when we're done...

[jimvw57]

doing the "seal the motor and pump it up test" will tell if the seals are shot, but it also is kind of a backwards way of testing it. You want to be able to see if the motor is PULLING air into the motor, and pressurizing it will tell if it is leaking out. (kind of backwards) so it may pass the test, but still have bad seals.

I can pull a motor, reseal it and have it back in on a long saturday, but I usually spend a day to get it apart, and resealed, and a second day cleaning up the chassis, lubricating everything under the motor, replacing fuel lines, etc before putting the motor back in place.  Perfect time to get things right with the motor out.

[IraqvetUSMC]

Sorry this is so late rminier and jim. I have been so busy lately and just got around to getting my sled to my house from my friends house last weekend and I am just getting into tinkering with it now. I do really appreciate your kindness on helping me with this old girl and going as far as wanting to help me personally term into this thing. Since I got such a late start I am not sure I want to change the seals this summer. I am hoping to clean it all up and clean out the carbs and check the little ball check valves for any issues. Speaking of cleaning, I would really like to clean the engine and pan as best I could with gunk without removing the engine since its all oily, dirty and some debris in it. Unfortunately their is no access panel to drop but on the right side their is a hole. How have you guys in the past cleaned this out with out tilting it on its side to let everything drain out? Will it just wash out that hole? And i tried a electric staple gun on my homemade seat cover and ya right lol the staples just hit that hard plastic and flew across the room haha. I was thinking of heating the plastic to soften it up a bit.

[rminier]

  I have used a variety of things to clean out the belly pans...Formula 409 spray, something I think was called "purple power" degreaser from NAPA worked well to cut through grease....sometimes just hot, soapy water if it's not too bad.
  Usually the water just runs out of the area beneath the motor..sometimes kinda slowly, but there are enough small gaps around rivets, seams, etc. that allow the water to drain.

[IraqvetUSMC]

So I went to town with about 2 cans of gunk and a pressure washer on the sled and had it tilted sideways. That cleaned it out pretty good lol. Just need to get this thing running right I installed new seals in carb float bowel and drain plugs as the plug seals were blown out and both plugs were loose. Its almost like the sled doesn't want to stay running and you have to keep playing with the throttle. It doesn't want to sit at an idle. I have spark, air (open) now lol and I believe fuel as the carbs are full of fuel. Im starting to wonder if I have a compression issue or bad rings. Do you know what the compression calls for?

Thanks

[rminier]

Hey, how are you doin' young man?
 The compression you should have...depending on the variability of various compression gauges...(cheap Chinese or Bangladeshian) ought to be somewhere from 120 to 140. It is more important that the difference between the 2 cylinders is less than 10 percent.
 Apparently, you have it running...so, a couple comments...
  It is tough to get these motors to always idle perfectly. They are much more high strung than a new Chevy Impala. I have had times with my various sleds when I have had everything dialed in perfectly, apparently, and I could warm them up and go watch an NFL game on TV, and come back to find them idling perfectly....obviously, you can't do that because they will quickly overheat. Other times, I have everything set pretty close, but still need to blip the throttle occasionally when the idle speed tends to fall back.
 The air screws on the side of the carb are very important. They are the ones that the head is about a 1/4 diameter and uses a straight blade screwdriver. They are normally set about 1 1/2 or 2 turns open from the lightly seated position.
 Unfortunately, trying to adjust these during an 80 degree August day will result in a much different setting than you would need in winter when it's 20 degrees....hot air is so much less dense than cold air....you may have to open them up 2 1/2 turns, or more, to get the best idle in warm weather.
 Never expect these engines to always idle as perfectly as a new fuel injected, computer controlled car.
 It's important to try and keep these screws adjusted nearly the same between the 2 carbs.
 
Unfortunately for you, us old farts on here are gonna continue to beat you up about the rubber crank seals, and the likelihood that they have deteriorated over the years and are no longer creating a perfect, air tight seal.
 And, take a close look at the rubber carb boots, to make sure they don't have any cracks that could leak air into the motor.
Keep gettin' that Invader ready....and think SNOW!!!

Rick

[jimvw57]

If you have less than 100 psi, you will have troubles. Ideally you want about 150 or better, and the cylinders should be within 10% of each other. The normal is around 120-130 for a good sled. Also a compression check will tell you NOTHING about the crank seals.

You want to block the carbs wide open and pull over the sled until the compression gauge tops out for a good reading. Best to do a cold reading and then a hot reading (warm the motor up )

Another quick shot from an old guy about crank seals, checking them with the air pressure test will tell if they might leak with the motor cold, they usually fail once the motor warms up and you are doing top speed across a lake. That way you are sure to melt a piston and cylinder before you can stop the motor.

Crank Seals, Crank Seals, Crank Seals.... I have said enough.

[IraqvetUSMC]

Hi Rick

I am doing fine.  A few months back I bought an older dirt bike to start riding motocross again to get in shape. I rode MX as kid for a long time and haven't rode in 13 years so I got a bug up my A$$ to start riding again and in a couple years I am going to get a bike for my son so we can ride together. I rode yesterday and this morning I feel like I got hit by a semi lol. I am deff not 15 anymore, I used to be able to ride for hours as a kid only stoping for gas, food and drinks not because I was all worn out. Now I know why my dad would ride for a half hour and then crack open a beer. Getting old sucks lol. You made a valid point with the air screws on the carb and the hot weather outside. From day one the sled would idle fine even after the whole hill climb ordeal that started this issue once it got it started again it would idle fine. I think since I set the air screw to factory settings in this 80 weather that messed it up. Once I chop the throttle and play with it I can get the sled to run great wide open with the track suspended in the air. I believe I have the seals, they are made by Winderosa and the part # is GS1149. Im just worried about fighting 40 years of rusted bolts lol.

[mswyka]

Read back through a couple of these posts.  Sounds like the crank seals have not been changed.  If that is the case, there is probably no benefit in doing any fine tuning.  As far as idling, when you go to put it back together, make sure that all of the pilot jet passages are thoroughly cleaned and the "moat" in the needle jet has been cleaned of gunk.  The moat shows in the attached photos.  There is an air passage at the base of the moat that helps to mist fuel into the carb at idle.  And I will add that I recently sold a perfectly good sled because I needed the space, and I couldn't get it to idle.  New owner changed the carbs and was back in business.  Even though I had new pilot jets, something must have been up.  So,  if you do everything else right and she still won't idle, it might be time to change the pilot jets again - and/or swap in a pair of carbs from a running sled.

[IraqvetUSMC]

I definitely think that its my carbs now. That day that my sled died out on me and i couldn't keep it running once i got it running i never pulled off the second carb to inspect. When i cleaned the sled the other day I had removed both carbs and then reinstalled them without taking them apart. When I  tried to start the sled after filling it with fresh fuel it ran shortly and died thats when i noticed underneath the puddle of fuel. I removed both carbs and found the float bowl plug on the inside carb was very loose and had a blown o-ring, i am assuming it came loose that day and was sucking air and thats probably what caused the initial problem and since the sled was oily underneath and snowy i didn't realize the fuel spill from the get go. I noticed that left jug was full of oil and the right jug was dry without a spec of oil on the spark plug. Now the book calls to seat the idle stop screw and back off 6 complete turns and the air screw 1.5 turns from seat. But like Rick said this isn't the correct setting for 80 outside. To test this theory should i turn the idle stop screw only 3 turns from seat and what about the air screw? Also i noticed it a little wet with fuel around the rubber intake where the carb slides in which could be from not being adjusted properly.