ChadD 44 Posted January 26, 2021 Complete rebuild on a 2001 400ex . I don't believe there is a nut or bolt I have not touched on this thing. Anyway the problem I'm having is that no matter what I try it pumps all the oil out of the engine and into the oil tank. I've tried 1 quart in the engine and 1 in the tank, 2 quarts on the engine and none in the tank. I have even changed the oil pump with a brand new honda one. It wont even generate enough oil pressure the disengage the decompression release on the cam. Any and all help or suggestions are greatly appreciated. Share this post Link to post Share on other sites
jeepwm69 7,719 Posted January 26, 2021 @oh400ex you have any ideas? Share this post Link to post Share on other sites
Tim-ANC 202 Posted January 26, 2021 I there an oil pressure relief/bypass valve on these? Share this post Link to post Share on other sites
Fishfiles 20,147 Posted January 26, 2021 @SlammedRanger would be the EX guru !! 1 Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 @SlammedRanger look forward to hearing your thoughts. Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 1 hour ago, ChadD said: @SlammedRanger look forward to hearing your thoughts. Man my head grew 3 sizes! He called me a guru hahaha. So you have a clog somewhere in your oil system. Most likely place is the screen in the bottom of the oil tank. The lower line screws onto a removable bung that has the screen built into it. Remove the lower line then remove the bung. My bet is the screen is clogged up bad. 2 Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 @SlammedRanger this motor was completely torn apart, new hotrod crank, wiseco factory size piston and new jug etc etc. That was one of the first things I did was pulled the oil tank bung and cleaned it and sprayed it inside and out with some brake clean. No change. Last night out of running out of ideas I even cut that screen off of the bung (I do plan on replacing it) there was still no change. I wish it was that simple. I also forgot to mention that I don't think the oil pump is ever priming on the suction side as my oil filter was pretty much dry. Fyi I did take the time to spray brake clean and blow the lines and cooler with compressed air afterwards. Thanks again. Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 1 minute ago, ChadD said: @SlammedRanger this motor was completely torn apart, new hotrod crank, wiseco factory size piston and new jug etc etc. That was one of the first things I did was pulled the oil tank bung and cleaned it and sprayed it inside and out with some brake clean. No change. Last night out of running out of ideas I even cut that screen off of the bung (I do plan on replacing it) there was still no change. I wish it was that simple. I also forgot to mention that I don't think the oil pump is ever priming on the suction side as my oil filter was pretty much dry. Fyi I did take the time to spray brake clean and blow the lines and cooler with compressed air afterwards. Thanks again. I have to start simple and progressively get harder here. So dont take this the wrong way. Is the oil filter in the proper direction? Rubber side with hole facing the outside of motor. And the spring in place behind it? Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 I understand completely, not everyone has the same mechanical ability. Yes the oil filter is installed correctly. Spring in first then the filter with the rubber grommet side outside then the engine cover. Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 Ok. Next thing i will ask. Did you put any oil in the new oil pump? Kinda bench bleed it like you would a car oil pump? Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 That I did not do. May be keeping it from priming. Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 Just now, ChadD said: That I did not do. May be keeping it from priming. Yeah when i did my stroker build i actually learned a cool trick when doing a rebuild on my dads vw dunebuggy engine years ago. Take a bit of moly lube. Assembly lube. And put it in between the rotor and gear in the oil pump. It helps it prime instantly. Before that on all car engines i have rebuilt we always just bench primed them and made a huge mess lol. 1 Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 We always use an old distributor to prime out engines. I will take it apart tomorrow and fill it up with oil. Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 Just now, ChadD said: We always use an old distributor to prime out engines. I will take it apart tomorrow and fill it up with oil. Yeah we do that too. But if you fill them first it can keep from getting an air pocket stuck and it not priming. That method works until you run into an engine with a crank driven oil pump. Like my dads vw buggy engine. 1 Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 Like a ls engine. 1 Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 26, 2021 4 minutes ago, ChadD said: Like a ls engine. Thats wicked! Me and my brother built his ls1 in his transAm. Not even close to that caliber! Did a mild cam and tougher bottom end (since he killed one of the stock rods with a 300 foot burnout lol). Polished crank and king bearings and stuff. We built it for a 150 shot but he never got to the point of spraying it before our track closed for the year because of covid. He did go 11.4 n/a. We were really trying for a 10 but never got it. 1 Share this post Link to post Share on other sites
ChadD 44 Posted January 26, 2021 That's cool. It's just a run of the mill 6.0 600+ lift cam, 160 bosch injectors, forged pistons, h beam rods and a 94mm turbo. Pretty sure I'm gonna run out of fuel pump before I run out of motor but we will see. And everything you see was done by me, good or bad. Lol 2 Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 27, 2021 18 minutes ago, ChadD said: That's cool. It's just a run of the mill 6.0 600+ lift cam, 160 bosch injectors, forged pistons, h beam rods and a 94mm turbo. Pretty sure I'm gonna run out of fuel pump before I run out of motor but we will see. And everything you see was done by me, good or bad. Lol Everyone told us to just get a 6.0 and forget rebuilding the ls1. But i told him if we rebuild it we know its all new. That 6.0 could have had a rough life? Who knows? We did H-beam rods aswell. He also did a ls3? Intake. Fast 92mm throttle body? Its stalled and geared. Has texas speed long tubes. Im sure im missing things and butchering names of things lol. Not my car and we did this build 2 winters ago. He had to upgrade injectors and he runs a wide band on it. Factory injectors couldnt handle the "sloppy stage 2" cam. I know i got that one right! Because its hilarious! 1 Share this post Link to post Share on other sites
ChadD 44 Posted January 27, 2021 Old sloppy changed the way people are doing this stuff. It's crazy some of the stuff he used to do. Sounds like a really strong build. Share this post Link to post Share on other sites
ChadD 44 Posted January 27, 2021 Ok so after working a 12 hour midnight and getting a 4.5 hour nap I'm out in the garage and I'm about ready to burn this P.O.S to the ground. At one point a few weeks ago I actually got the cam to turn and saw oil pumping but it would run the engine dry and lose prime to the oil pump. I actually got the motor to start for a few seconds. Bought a brand new honda oil pump and installed it. Now It doesn't ever build enough oil pressure to disengage the decompression release so the cam never turns. This was a complete tear down, new hot rod crank and bearings, new tranny bearings, wiseco 10.1 factory bore piston, new jug etc and a new ebay stage 2 cam that came with the decompression crap on it so I bought a new spring and plunger. Anyway I tore the clutch side case off and checked everything again and even cranked it over and it shot oil out of every hole I could see. Put it all back together putting 1 quart each into the oil tank and the engine. Cranked it over for probably 3-5 minutes off on and I never saw oil come out anywhere on the top end. I have the header side rear valve screw off so I could watch. I did put a little bit of air pressure on the oil tank vent hose which actually did fill up the oil filter with oil. Anyway if anybody can think of what in the crap I'm missing I'd appreciate it. Share this post Link to post Share on other sites
Wheeler 2,527 Posted January 27, 2021 K so I’m not a sport quad guy. Don’t know the 400ex. However I rebuilt entire engine, everything was done correct &cleaned. New oil pump, & top end not getting oil? so that tells me either a line/passage must have dirt in it.. only thing that makes sense. If the oil can’t get thru, she gonna run dry... Share this post Link to post Share on other sites
TBRider 1,411 Posted January 27, 2021 If the oil filter is put in backwards, does that not restrict oil to the top end ? 2 Share this post Link to post Share on other sites
ChadD 44 Posted January 27, 2021 (edited) @Wheeler I'm beginning to think the same thing. I know I'm sure that I don't want to have to rip it all back apart but you do what you have to. Edited January 27, 2021 by ChadD Share this post Link to post Share on other sites
ChadD 44 Posted January 27, 2021 @TBRider I would almost guarantee you would be correct but I can assure you that the oil filter is installed spring first then oil filter with the gasket side on the outer cover. 2 Share this post Link to post Share on other sites
SlammedRanger 1,559 Posted January 27, 2021 Well the cam should turn reguardless. All the decomp does is crack a valve open slightly by holding the rocker arm tab. If your cam aint spinning there is a big problem. The piston will have done hit a valve 100% for sure. If your getting oil spitting out everywhere but the topend there is one small passage running up there. It runs up the right side of the jug and head and into the valvetrain area. I would remove the oil filter and blow air up the hole leading up there. It should be about 8 or 9 o'clock if looking at it from the right side of the quad. Did you by chance replace the clutch side cover when doing the rebuild? There is an oil seal that goes in that cover held in with a clip that slides over the snout on the end of the crank. That is what oils your crank and 90% of the bottom end. 3 Share this post Link to post Share on other sites