Decompression hole plugging

[motopsycho87]

Just wondering if the bikes that don't have the decompression hole above the exhaust port are difficult to start. Getting my cylinder replated and considering getting the hole plugged up..?

 

[TheLetterJ]

Kinda. I actually drilled the hole into my cylinder before sending it out for plating last year (maybe the begining of this year?) in an effort to make it easier to start. Riding my 300 back to back with a cr500, they took the same amount of effort to light. Significantly harder to kick than my old cr250, or any 250f. I have not been back on my bikes since, so I don't actually know how much difference it makes. I know you've been chasing all the little things to get more power (and I'm trying to follow your footsteps on things like grinding the pv flapper) but having the bike start easy is worth any potential power loss to me. Every KTM 300 cylinder I've seen has had the decomp hole drilled above the exhaust port too.

 

[motopsycho87]

I think it's all in tech ique starting really though, I always bring to TDC slowly then kick it a good stomp, seen too many broken kick-start from just hammering it (not that I'm saying that's what you're doing!)

 

[Zman]

When my son was smaller and lighter we needed to make his 2004 DE300 easier to start. The earlier bikes did not come with the decompression hole.

Eric Gorr modified a stock head to include a decompression button that made it much easier to start. We also installed the longer Yamaha kickstart lever.

 

[motopsycho87]

Turns out mine had a blob of weld on the exhaust side of the decompression port. So I didn't really have one anyway! Turns out my low compression must have been from badly seated rings (bore was shiny as hell) or the bore is out of round, anyway, it's off to be plated .