Engine Rebuilt, Now wont start, and makes horrible dump valve sound when turned off
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Hi, looking for some advice...
I rebuilt my bottom end and have put it back in the frame, connected electrics and put coolant in the radiator. I just tried kicking it over (about 10 kicks) and nothing happened. I then turned the on/off switch from on to off, and all of a sudden the bike released a load of pressure, it sounded like a dump valve. Did it once more (only a couple of kicks) to see if it was a fluke, and it happened again. To add insult to injury my coolant is now drip leaking from the crank sealant. Has anyone got any idea what might cause thise to happen or how to rectify it? Could wiring it up wrong have caused this?
Thanks
James
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Did you have the rad cap off when kicking it over?
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No! Which i then realised, so when i tried it again i did have it off. Although that might have caused the leak initially i still dont think it explain the dumping noise and lack of ignition? Any ideas? Thanks for your help.
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@jamesdowning Always keep it on dude, as the cooling system needs to be pressurised.
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@NINJA if you've put fresh coolant in an empty system you need to bleed it though
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@finnerz89 yeah, but it shouldnt stop the engine starting should it? So confused now haha.
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The main concern is that it wont turn over, and that pressure (pressure that i dont think should be there?) is dumped when the on/off switch is turned to off.
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@jamesdowning You sure it's not just the powervalve mate.
Turning the ignition on and off isn't going to dump any pressure.
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@jamesdowning It sounds like something is not connected correctly or you've damaged a seal when bolting everything back up? If the system is not pressurised and air is trapped in there, then that would most likely give you the dumping sound which you refer to? As @finnerz89 said you need to bleed the system and put new fluid in without adding air. Using a plastic syringe which can be easily bought off ebay is ideal for this, as well as being perfect for bleeding brakes too. If you can connect it at the bottom and pump fluid up-hill, leaving the rad cap off, then using the plunger in the syringe pull it back and forth to pump fluid in and out, that will blow air out of your system.
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I'd say the pressure noise would be the plug igniting fuel in cylinder, noticed on my dtr it would produce a weak spark couple times after kill switch was set to off.
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@Calum my dtr doesnt have a servo style powervalve, it has the old style where you set it how you want it. Therefore dont think the ignition would move it. I agree the switch shouldnt have any effect on the dump noise but it deffo did. Bit weird, hence why i think i might have wired it up wrong somehow
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@NINJA Thanks fir the tip mate, yeah think the seal is now damaged, but think the damage was caused as a result of the sudden high pressure build up, as apposed to me damaging it on assembly. Cheers for the pointers
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@jamesdowning It's nothing to do with Age about having a powervalve on a DTR.
Since the LC's were fitted with YPVS Servos.
The earlier models were about proving you had the appropriate license to have one. The later models were restricted in other ways, but kept the servo.
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@DTR-NSR ok, definitely possible and sounds like it could be the case! I'll have a look
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@Calum So a 97 dtr can be fitted with a servo? Bit confused mate haha
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@jamesdowning Yeah, the older models ran an independent 3 wire servo. Unlike the 5 wire ones on the later models.
Having a servo is well worth it. All benefits no cons.
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I'd check you've got a healthy spark kicking it over with kill switch set to run. Does sound electrical with it being connected with touching switch.
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@Calum I'll look into it once this bloody bike runs! Cheers mate
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@DTR-NSR thanks! checking for a spark will be next on the cards! If theres no spark does anyone know the most likely causes? Or is that a stupid question? Guess theres plenty of reasons for not getting a spark?
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I imagine the sound you heard was like the first few seconds of this vid?
In that bike's case it was the bottom end on the way out and there was play in the conrod but obviously shouldn't be the case with your bike.
Could be compression related though I guess.. Did you get your cylinder checked for correct sized piston?
