TDC on compression stroke

[TxAg66]

Question on my 2003 DF25 4-stroke triple

My manual tells me to be sure the top cylinder piston is at TDC on the compression stroke when installing the fuel pump.

Question is, how can I tell if it's on the compression vs exhaust stroke?

I'm studying up on how to pull the carbs, & the manual tells me I need to pull the fuel pump which, of course, means I need to be able to put it back in.

Thanks in advance for helping me with what might be a pretty elementary question.

[Harper]

You can pull the valve cover and check that both valves are closed on that cylinder, indicating that it's on the compression stroke and not the exhaust stroke.

[jHydroman]

Remove the top spark plug, place your finger over the spark plug hole. Turn fly when in direction when engine is running. You will feel pressure on you finger stop rotating when TDC marks line up.

Jim

[TxAg66]

Remove the top spark plug, place your finger over the spark plug hole. Turn fly when in direction when engine is running. You will feel pressure on you finger stop rotating when TDC marks line up.

Jim

Jim, thanks. That makes sense + is simple. Simple is good!

[Hoosmatroos]

+1

And when you feel the pressure rising then you know that's the compression stroke. To be shure that your on top, put a straw or something like that through the spark plug hole against the piston and then you can find out what the TDC is.

[Harper]

Much better idea than mine...

[TxAg66]

Thanks to all. One more piece of very useful info I now have in my bag. Damn, I love this forum! Just think: constructive input ranging from TX to WA to the Netherlands. What a database!

[Harper]

Thanks to all. One more piece of very useful info I now have in my bag. Damn, I love this forum! Just think: constructive input ranging from TX to WA to the Netherlands. What a database!

Don't forget Australia.

[TxAg66]

Don't forget Australia.

Oops, did I miss The Land From Down Under? Sorry .. Thought I was just referring to the folks who replied to my dinky little question. But maybe there's an Aussie who might live in the TX Hill Country?