wera803 Posted June 25, 2015 Share Posted June 25, 2015 The water is not getting around or through the spark plug threads and into the engine. No water in the plug/COP cavity prior to removal, in fact this time, the COP was dry as it was removed from the cavity. Thanks for the clarification. It seemed like several were speculating water was passing the spark plug threads. I know you probably know the details of these bikes better than anyone else I know, but personally I thought looking at a picture would help me. So fresh air comes in the top of the air box (white arrows). Looks like the PAIR could let water in on the exhaust valve. Blow-by gas comes thru the breather and into the air box as well. It shows the fresh air going through the air funnels and the blow-by gas going through some small passage along side the air funnel. Not sure why they show it like that though. If water was getting in the breather system anywhere outside the airbox, it would end up in the oil, not in the piston. So it seems airbox or PAIR cover would be the logical spots. Maybe you could stuff a wash cloth in the intake track, put it together, then use a hose to soak it down. Pull it apart and see if the washcloth is wet and if water is still in the cylinder? Link to comment Share on other sites More sharing options...
Member Contributer CornerCarver Posted June 25, 2015 Author Member Contributer Share Posted June 25, 2015 Ken thanks for adding the diagram to the discussion! It really helps everyone visualize the possibilities. We initially thought it was coming in through the airbox as I have been running a open lid airbox on my 5G for years and Mini copied this when he put his Frankenviffer on the dyno to program the PC to provide proper fueling for a 5G engine running a VTec ECU. We now have one of the tightest airboxes I have ever seen on a motorcycle and no water is getting anywhere inside that. I will circle back to Cogswell and your idea of a tattletale and place something in the intake tract as well as surrounding the plug and re-install the COP then soak sufficiently with a garden hose to see if we can recreate the issue. For now Mini has ordered another set of Pair block off plates and we are waiting for them to arrive but this test would certainly give us more confidence in that as the solution. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted June 25, 2015 Member Contributer Share Posted June 25, 2015 We now have one of the tightest airboxes I have ever seen... No need to brag! Link to comment Share on other sites More sharing options...
Member Contributer CornerCarver Posted June 25, 2015 Author Member Contributer Share Posted June 25, 2015 We now have one of the tightest airboxes I have ever seen... No need to brag! The reason most people toot their own horn is because no one else knows the tune... Link to comment Share on other sites More sharing options...
timmythecop Posted June 25, 2015 Share Posted June 25, 2015 yet another reason to leave the pair alone. Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted June 25, 2015 Member Contributer Share Posted June 25, 2015 Tight airbox and a good PAIR. What else could a guy ask for! Link to comment Share on other sites More sharing options...
MVinOZ Posted June 26, 2015 Share Posted June 26, 2015 Haha, quality thread! Never seen a problem like this before, but logically, it could only be coming in via the inlet or valves... Unless it is coming from inside the engine itself. Hope you solve it, curious to see what it is! Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 You can visual inspect for a leaking head gasket by pulling the sparkplug and peering down suspect hole... if the top of the piston is blackthen no leak that cylinder... if the top of the piston is a brightshiny aluminum then leak detected... because a leaky head gasketallows coolant in and that produces steam under the heat ofcombustion... the net effect is a super clean piston dome instead of nastyblack... Link to comment Share on other sites More sharing options...
Member Contributer kebrider Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 You can visual inspect for a leaking head gasket by pulling the spark plug and peering down suspect hole... if the top of the piston is black then no leak that cylinder... if the top of the piston is a bright shiny aluminum then leak detected... because a leaky head gasket allows coolant in and that produces steam under the heat of combustion... the net effect is a super clean piston dome instead of nasty black... Pretty sure the problem only occurs when the bike sits in the rain. PAIR system looks like the most likely culprit though looking at the posted diagram the blow-by gas path indicated is another prime suspect. Also looking at the vacuum hose diagram in the shop manual the way the 5-way tee is configured if water were to get into the tee the majority of it would drain into Cylinder 1. That is based on the diagram and I don't have a VFR anymore to check it out. Be a great test to pull the number 1 hose and extend it with a fitting to a long section of tubing and then spray the bike down. Could also put some soft paper under the PAIR plate and do the same test to see if that is the point of entry. It's supposed to rain here all day tomorrow. Ride the bike to Knoxville and we shall test it proper. Got plenty of VFR braintrust members that live within a few miles of each other up here, maybe a fresh set of eyes will help. KEB Link to comment Share on other sites More sharing options...
Allyance Posted June 26, 2015 Share Posted June 26, 2015 Water may be collecting in one location, then getting sucked in on first crank. Check after rain but before cranking. Link to comment Share on other sites More sharing options...
Member Contributer CornerCarver Posted June 26, 2015 Author Member Contributer Share Posted June 26, 2015 The GDC 6G that we built last year has been plagued by an engine that will not start after a rain. We initially thought it electrical but found some water in the oil. We wondered about head gaskets as the engine has over 65k miles on it now. They are also good. We have been getting heavy rain this year in the south. We have tried to find an area where water/rain could get into the engien and hydro-lock it unsuccessfully. This past week we confirmed that the only cylinder that is getting filled with water is the left rear. We have fabbed up various brackets and gaskets to seal the COP's to the 5G heads and do not think that rain is getting in past the COP's. We have had the airbox off more than 2 dozen times to search for issues and have had the throttle bodies off half a dozen times to look for loose hoses. We placed the bike on a rear stand for the latest round of thunder storms to eliminate the thinking that leaning on the sidestand was somehow contributing to this. We have found no loose hoses or vacuum lines that could funnel rain into the cylinder. After a heavy rain the engine will either not move at all when the start button is pushed or (if the left rear cylinder is close to the bottom of the bore) the engine will turn for less than a quarter revolution and then lock. That is not enough rotation to pull liquid in through a vacuum line or loose hose even if submerged in a container of water. Any ideas or recommendations? Our next step if we cannot solve this issue is to put the 4G back on the road for commuting and remove the engine from the frame to start over. TIA Not coming in via a vacuum hose....no where near enough revolution to generate any vacuum. Actually usually no rotation at all. Link to comment Share on other sites More sharing options...
SEBSPEED Posted June 26, 2015 Share Posted June 26, 2015 If the PAIR system is letting water in, then it will also let blow by vapors out... any grimy areas near the system parts that would indicate a leak? Link to comment Share on other sites More sharing options...
Member Contributer Rice Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 I am completely baffled by this. Hope you figure this out Carvers. Not sure if you've doneit already, but pur some water on the bike and see where it goes... PAIR block off plate is VERY unlikely, unless you have an upturned funnel screwed into it. Spark plug is also a no go, since there is a drain channel (presumably not blocked). Vacuum is also not a problem since there is none while parked. Air box? No way in hell. Injector not sealed properly and letting water stream into the cylinder? Big Maybe. Baffled, as I said. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 Just for my satisfaction I would put that cylinder on TDC and pull the plug and insert a adapter and pressurize the cylinder. Then listen for escaping air. Don't know if it will enlighten the problem or not BUT we are fast approaching a brick wall . Roll On .. Link to comment Share on other sites More sharing options...
Member Contributer Rectaltronics Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 Water may be collecting in one location, then getting sucked in on first crank. Check after rain but before cranking. In Soviet Russia, crank sucks you. Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 Pretty sure the problem only occurs when the bike sits in the rain. PAIR system looks like the most likely culprit though looking at the posted diagram the blow-by gas path indicated is another prime suspect. KEB At this point you want to eliminate every possibility... Pair is the exhaust side... any water that collects there will be blown out... check the intake side... like the screw below the intake boot that seals off the throttle synch port... Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted June 26, 2015 Member Contributer Share Posted June 26, 2015 Pretty sure the problem only occurs when the bike sits in the rain. PAIR system looks like the most likely culprit though looking at the posted diagram the blow-by gas path indicated is another prime suspect. KEB At this point you want to eliminate every possibility... Pair is the exhaust side... any water that collects there will be blown out... check the intake side... like the screw below the intake boot that seals off the throttle synch port... RC Forty-What? No, RC46. PAIR has two tubes per bank that lead directly onto the inside exhaust valves of each cylinder. It is possible that the valve on cyl 1 is slightly blocked and not sealing. That would allow water direct access from the pair to the cylinder. Same with intake ports. Even if there was a leak, the valve would have to be blocked from completely sealing. On either side, it would have to be an incredible coincidence that every time he parked it and it rained, that valve was sitting open. Oh by the way, the spark plug tubes have drains just above the spark plug threads that drain directly out and under the exhaust ports. Anything else looks like it would just allow water into the valve train area. That would only drain into the bottom of the crankcase. Even if it somehow filled up the valve spring seat, it would have to drain down past the valve guide seal. That would present burning oil in the exhaust far sooner than filling up a cylinder. I've got a completely disassembled RC 46 engine in my garage, and there just aren't any more paths into the cylinder other than through the valves via intake boot leak, PAIR leak, valve guide seal leak, or head gasket leak (which would present other, bigger issues). Same with spark plug leaking. #1 there's a drain, #2 combustion would have done far worse coming out. The exhaust ports are angled down, and have a lip over them. No way for rain water to counteract gravity. May want to do a valve clearance check to see if one is way out of line. My vote is the inside exhaust valve on #1 cylinder. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 27, 2015 Member Contributer Share Posted June 27, 2015 Is there a chance you have a crack in valley in between the two air intake ports at the top part of the airbox ? Roll On .. Link to comment Share on other sites More sharing options...
Member Contributer CornerCarver Posted June 27, 2015 Author Member Contributer Share Posted June 27, 2015 Rained pretty hard here today (again - sorry California) so on my way to remove a spark plug and take some video so Mini can get home from work...BRB. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 28, 2015 Member Contributer Share Posted June 28, 2015 Can't wait . Roll On .. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 29, 2015 Member Contributer Share Posted June 29, 2015 Long video ? Roll On ... Link to comment Share on other sites More sharing options...
Member Contributer Rush2112 Posted June 29, 2015 Member Contributer Share Posted June 29, 2015 Long video ? Roll On ... I'm dieing to know what is causing this... I logged on last night to see the video... Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted June 29, 2015 Member Contributer Share Posted June 29, 2015 Maybe we'll get video of the house remodeling instead... Link to comment Share on other sites More sharing options...
Member Contributer Polarbear Posted June 29, 2015 Member Contributer Share Posted June 29, 2015 That would be fun too. Is it also hydro locked?? ............ I, too, keep checking back to see the progress. C Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted June 29, 2015 Member Contributer Share Posted June 29, 2015 Maybe we'll get video of the house remodeling instead... Hot dam that's funny ...... Your suppose to remove the motorcycle BEFORE entering the water ... Roll On .. Link to comment Share on other sites More sharing options...
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