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Did Leak down test ..unsure of results..

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Alright, so the problem is that my 05 crf450r will bump start and run well, but refuses to kick start. It was suggested that i try to check the compression...this is what happened.. Any help would be greatly appreciated. Thanks..

1. Disabled auto decompression.. I could get 1-2 kicks in before it became to much compression to kick..however by moving the kickstart level up about half way( instead of all the way up), i could continue to get short kicks.

2.Installed compression gauge into spark plug2.gif hole. Put bike in 5ht gear and attempted to push it down the street. Tire wouldnt turn at all, would just slide on the street..So nothing useful from that..

3.Tried to do a leak down test. Got to around 95 PSI in the cylinder. However, i have gurgling in the oil. It has to be coming from the crank case.No noise from air box or exhaust.

Here is a video. At the beggining of the video is when i start to open up the regulator . The gurgling starts imdediatley..

Can you guys derive anything from this??

To me it means air HAS to be getting past the rings...??

http://s146.photobucket.com/albums/r...t=102_1584.flv

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I don't think he got an % at all. If you have the piston at TDC on combustion stroke so the cam lobes are off the valves, meaning free play from cam followers to rockers, and you still get gurgling then I'd say you have a hole in the piston. But if that was the case you'd have been able to kick it over like it didn't have a spark plug in the hole, and you can't kick it very well you said. I wonder if it's partially siezed and the pressure is going past the rings and scored cylinder walls.

If you are at TDC and don't hear any air from the intake tract or ear to the muffler, then I'd say top end damage.

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all you have to do is look at the gauge on the leak down tester.

yea, the damn thing wasnt working. I mean, after thinking about it now, how can i get a percentage loss when i couldnt get a base pressure?

I mean, as soon as i started pumping pressure into the cylinder the pressure was escaping so i couldnt even get a base pressure to go from.

It would just constantly take air pressure from the tank(ai compresor) so the air pressure had to be going some where.

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I don't think he got an % at all. If you have the piston at TDC on combustion stroke so the cam lobes are off the valves, meaning free play from cam followers to rockers, and you still get gurgling then I'd say you have a hole in the piston. But if that was the case you'd have been able to kick it over like it didn't have a spark plug in the hole, and you can't kick it very well you said. I wonder if it's partially siezed and the pressure is going past the rings and scored cylinder walls.

If you are at TDC and don't hear any air from the intake tract or ear to the muffler, then I'd say top end damage.

i guess the simple way to check is to full the top end off and check? I had the top end off a month or so ago and the walls of th cylinder looked reallllly good. It had ver even cross hatching and no nicks or deep scratches at all.

Also, my best guess is that the part about not being able kick it very well is due to the fact that i disengaged the auto decompressor.

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If you cannot get any pressure build up, the guage would be close to 90-100% leak there. It is really simple tool to use and figure out.

Sounds like cylinder could be oval, piston/rings and gaskets/seals are leaking.

I think your best plan is to expect to put in a new crank/bearings/seals, do the counterbalancer bearings and seals, inspect the water pump, measure the cylinder and replace as needed, new piston/rings and since you are that far, new valve train in the head, cam chain and tensioner. Basically complete motor tear down.

But that is just from the info you have posted as to having close to 100% leak in the bottom end.

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If you cannot get any pressure build up, the guage would be close to 90-100% leak there. It is really simple tool to use and figure out.

Sounds like cylinder could be oval, piston/rings and gaskets/seals are leaking.

I think your best plan is to expect to put in a new crank/bearings/seals, do the counterbalancer bearings and seals, inspect the water pump, measure the cylinder and replace as needed, new piston/rings and since you are that far, new valve train in the head, cam chain and tensioner. Basically complete motor tear down.

But that is just from the info you have posted as to having close to 100% leak in the bottom end.

yea....thattss alot...:bonk:..

I dont know if you have seen my other thread. The thing i dont get is the bikc will bump start. It will run with great power. It just pops a little on hard decel. It will not kick start however...thats whats promting all this.

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Is it the oil gurgling, or possibly coolant? I just cant see the oil gurgling like that.

nope. couldnt be coolant. There was no coolant in the bike..

i know..the oil bubbling right off the bat is blowing my mind..

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I see the bike runs, but sounds like not very well. I would suggest to redo the leak test with the valve cover off, header pipe off and carb off. If you dont find anything different, tear down the top end and inspect/measure things up.

The reason I said complete motor rebuild is for one I dont have the bike nor will I to diagnose it better, plus if you do either top or bottom and not the other, you may have a failure on the parts you did not fix. Might as well spend the money now, have a fresh motor and piece of mind. But that is the way I do things, dont skimp

oil bubbling is from a leak past the rings or hole in the piston or oval cylinder or crack in the cylinder/cases. Make sure you know if it is the engine and/or tranny side.

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yea....thattss alot...:bonk:..

I dont know if you have seen my other thread. The thing i dont get is the bikc will bump start. It will run with great power. It just pops a little on hard decel. It will not kick start however...thats whats promting all this.

The reason it bump starts is because when you do that the decompressor is out of the mix and its got enough compression to start. The popping on decel hasnt got anything at all to do with whats going on.

see if you can do this.

Pull the cam tower off the bike. Pressurize the cylinder again and listen in the intake. You need to have everything else quiet. after pressurizing the cylinder, turn the compressor off.

Make sure the piston is at tdc. if its not, it'll just run to the bottom of the stroke and leak past the rings into the bottom end and you'll end up hearing the bubbling oil. You want to listen in the intake and the exhaust.

More than likely youve got a valve hanging open somewhere. You could have bent an exhaust valve and youre getting a double dose of "decompressor action" and thats why it wont kick start. Honestly the easiest thing to do is just pull the damn head off and look.

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The reason it bump starts is because when you do that the decompressor is out of the mix and its got enough compression to start. The popping on decel hasnt got anything at all to do with whats going on.

see if you can do this.

Pull the cam tower off the bike. Pressurize the cylinder again and listen in the intake. You need to have everything else quiet. after pressurizing the cylinder, turn the compressor off.

Make sure the piston is at tdc. if its not, it'll just run to the bottom of the stroke and leak past the rings into the bottom end and you'll end up hearing the bubbling oil. You want to listen in the intake and the exhaust.

More than likely youve got a valve hanging open somewhere. You could have bent an exhaust valve and youre getting a double dose of "decompressor action" and thats why it wont kick start. Honestly the easiest thing to do is just pull the damn head off and look.

Yea, i understand what your saying. I pulled the head off a while back and i didnt see anything abnormal. Here are some pics.. All the valves look to be sealed pretty well to me.

102_1327-1.jpg

102_1320.jpg

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broken ring

Probably.

If you had the head off already and didn't pull the cylinder, you made a mistake. :bonk:

If it was at TDC when you did the leak, and it didn't push the piston down and you did hear gurgling from the oil fill hole, the ring is leaking, and not just a little. If that is the case, I'm kind of surprised you haven't noted a fog bank of blue smoke out the pipe when it does run.

You really cant look at a valve and declare it to be sealed. Youve got to, at a minimum, fill the combustion chamber with alcohol and look for leaks into the ports. And a better test is to pressurize the intake and exhaust ports, or the combustion chamber with a block off plate.

Proper inspection requires the valves to be removed and the faces and seats inspected closely. This you can do in the garage.

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Probably.

If you had the head off already and didn't pull the cylinder, you made a mistake. :bonk:

If it was at TDC when you did the leak, and it didn't push the piston down and you did hear gurgling from the oil fill hole, the ring is leaking, and not just a little. If that is the case, I'm kind of surprised you haven't noted a fog bank of blue smoke out the pipe when it does run.

You really cant look at a valve and declare it to be sealed. Youve got to, at a minimum, fill the combustion chamber with alcohol and look for leaks into the ports. And a better test is to pressurize the intake and exhaust ports, or the combustion chamber with a block off plate.

Proper inspection requires the valves to be removed and the faces and seats inspected closely. This you can do in the garage.

oh...i see. The whole alcohol in the chamber thing i doubt i can do. Pulling the valves im sure i can do. I believe i just need a valve spring compressor correct?

Well the next thing im going to do is pull it all apart and look at everything.

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I haven't read all of the posts in this thread, or all of the posts in your other threads, but have you pulled the top end yet?

top end as in cylinder, piston, and rings?? No i havent. I just pulled the head off.

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Hard to tell from the picture but look at you left exhaust valve seat (right side in picture). Kinda looks like the seat is chipped right next to the plug hole.

your absolutly right. could that be the problem??

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