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View Full Version : can I start motor without exhaust pipe?


hntr58
03-02-2007, 09:45 PM
I just replaced the head on my Yamaha and dont have an exhaust pipe yet and was just wondering if I could start the engine to test it? Would it suck air back in and damage the exhaust valve? Thanks
BigReds Forever
03-02-2007, 09:50 PM
ive heard of this happening but never seen it my self, id at least throw the head pipe on if you just wanna test it out
El'Capitan
03-02-2007, 10:05 PM
i agree with bigreds, atleast have the headers on there -- you dont want to risk damage.
general_lee01
03-02-2007, 10:19 PM
if these no exhuast on it it will burn the valves up really quick
Dirtcrasher
03-02-2007, 10:39 PM
It will run HOT and LEAN...Whats the rush anyhow???

Test it? Check compression, thats it.
KASEY
03-02-2007, 11:44 PM
if you want to start it to see if your all put together right ,,, go ahead and start it!!!,,, it won't hurt anything to start it up..... i wouldn't ride it or anything like that but go ahead ,,,, just put your hand on the cylinder and make sure you don't get it to hot,,,,

WOW none of you kids ever took the muffler off your lawnmower to piss of the parents???? :rolleyes:
erectordale
03-02-2007, 11:54 PM
I did this as a kid with a 66 ford truck too piss off the sherriff lol he won that day cost me over $200 in tickets
84honda200s
03-03-2007, 01:15 AM
ive "tested" both 4 and 2 strokes without a exhaust and they are ok. however as said before at least put the manifold on. it will have at least some back pressure than.
Erics350x
03-03-2007, 09:00 AM
just starting it it for a few WILL NOT hurt it, your ears on the other hand....
Yamada
03-03-2007, 09:55 AM
just starting it it for a few WILL NOT hurt it, your ears on the other hand....

When I start my ytm 200 without header itt just make a glou glou sound at idle. But if i give it some gas that an other story.:naughty:

I think that of you just start it and let it idle for a few second you will not damage it.
TimSr
03-03-2007, 10:08 AM
It will be fine. Dont ride it around that way, or do extensive high revs. Nobody ever melted a piston from idling too lean!
will1806
03-03-2007, 05:43 PM
yeait will start but dont run it long. just be carefull. if it doesnt start up right away you will have gas leak out of the exhaust valve and when it will start its gonna throw a nice flame out of the exhaust. so be carefull for fire. i did this with my 500. started a nice little fire and i though my neighbors would shoot me. so just be carefull.