Does this look stock?

[TheHarp]

'08 YZ 450 ... bought the bike used, so not sure what was done to it by previous owner(s). It looks to me like the surface has been ground down a bit.

[KJ790]

Not stock, that's been ported. Looks like a home job. Now you have to find out if it was done by someone with any idea what they were doing or just a guy with a grinder thinking bigger is better.

[FarleyMX25]

yeah that doesnt look very pretty who ever was in there:bonk:

Edited January 8, 2010 by FarleyMX25
spelling

[TheHarp]

Yeah...I'm thinking someone went after it with a dremel tool.

[locomike]

Not stock, that's been ported. Looks like a home job. Now you have to find out if it was done by someone with any idea what they were doing or just a guy with a grinder thinking bigger is better.

I have my suspicions it is the latter. I cried a little inside when I zoomed in on the picture...

Anyway, how does the bike run?

[TheHarp]

I have my suspicions it is the latter. I cried a little inside when I zoomed in on the picture...

Anyway, how does the bike run?

It's a little slower than my CBR600RR race bike. I don't really have anything to compare it to, but I have no complaints.

[grayracer513]

If Ron Hamp has seen this, he is probably still vomiting at this moment. Or laughing. Or shaking his head in disbelief.

The bad part is that the 3 valve intake port is very easy to modify incorrectly and actually reduce the power output significantly. A really good head shop could correct it, even if it means material needs to be added back, but the first thing out of your mouth when you take it in should be, "I did not do this..."

[426 NOOB]

damn, that looks horrible. The previous owner should be shot.

[KJ790]

There are a few things going for it that suggest it may not be too bad. You can see he didn't touch the dividers, port bowls, or the short side radius, that's a good thing if you don't know what you are doing. It looks like the throats are ground slightly, hopefully it is nothing more than blending them into the seats a little. It looks like he cut into the floor right at the port entrance, then let the floor come up to the original height right before the start of the short side. I've seen head porters do this with success, and the good thing is that if it's done wrong it is an area of the port that least affects the overall performance. It sure isn't pretty though.

[grayracer513]

You can see he didn't touch the dividers,

Better have another look at that.

[Wes Woodin]

ugly:crazy:

[KJ790]

Better have another look at that.

The dividers look untouched to me, you can see they are darker gray than where he was grinding, and they still have a blunt edge.

[Qqqqqqqqqqqq]

[Ga426owner]

geez that is a hillbilly hack job ...... hopefully you can get it filled in and done correctly, but I would not wait. Call RHC Ron or someone knowledgeable to repair that mess. Makes me wonder what other wonderful things have been done or removed from your ride.

Edited January 8, 2010 by Ga426owner

[firemanmatt82]

If Ron Hamp has seen this, he is probably still vomiting at this moment. Or laughing. Or shaking his head in disbelief.

The bad part is that the 3 valve intake port is very easy to modify incorrectly and actually reduce the power output significantly. A really good head shop could correct it, even if it means material needs to be added back, but the first thing out of your mouth when you take it in should be, "I did not do this..."

Hey thats my line-if everyone starts using it, my mechanic will find out I can't ride or wrench on my bike. Lol

[TheHarp]

There are a few things going for it ...

That's good to hear...not sure I can spend the bucks this year to get it fixed. We'll see what else I find when I continue the tear-down.

[TheHarp]

Had a local machinist take a look at the head today. He said the porting is ugly but no real damage was done. He also found that I need new intake valves and a valve job. He has a flowbench, so he's going to measure the flow before/after cleaning up the porting.

He also recommended that I replace the rod with one from Hot Rods...so I'm probably going to be tearing into the lower end. This is my first time working on my own engine...wish me luck!

[TheHarp]

Update...flowbench says 188 CFM max flow....which, apparently, isn't too good. It doesn't mean much to me, I've asked him (the engine machinist) to provide some point of reference.

[grayracer513]

Ask him what the stock head flows on his bench.

[Ga426owner]

Had a local machinist take a look at the head today. He said the porting is ugly but no real damage was done. He also found that I need new intake valves and a valve job. He has a flowbench, so he's going to measure the flow before/after cleaning up the porting.

He also recommended that I replace the rod with one from Hot Rods...so I'm probably going to be tearing into the lower end. This is my first time working on my own engine...wish me luck!

this is going to get expensive with a new head and all of this otherstuff.....you need to decide if it is worth the cost. How much did you spend on this bike if you don't mind me asking? I hate it when sellers sell crap like this....