Porting and Polishing

[99tjrockcrawler]

What do you guys know about porting and polishing?  How much more power does it really give?  Any recommendations on where to get it done on the west coast.  I live in vegas.  I am really getting tired of those darn 450's beating me.  I run mostly in the sand and I know my bike is faster but with my weight the 450's take me a just a hair.  I want to add more power but not really tear intot the motor because I want it to stay reliable and it seems like the more mods you do the more it breaks.

Thanks for any help!!

MIke

[Arigato]

It definately makes a difference on the K5.  Send it to Eric Gorr and have him to the "mo betta everywhere" port job to the cylinderl.  There are a lot of casting flaws in the stock cylinder.  I live in 'Vegas too.  We should hook up and ride.

[reknelb]

You may want to check on turn around time before sending to Gore. I've seen alot of complaints online about turn around. I've also seen some of his responses to unhappy customers on a certain website. Not sure I would send anything to him myself, although I hear his work is really good. (and cheap)

[gowen]

I'd be for the porting from Gorr too, but I am a little pro-Eric, as he has hooked up most of my dirtbikes with no trouble and pretty fast too. Just be patient, he is one person handling hundreds of jobs. The outcome is awesome. Yes, dirtrider has had complaints, but I've never had any and have had 10 motors sent to him, 5 being ones I owned.. (including my KX, it is in for the second time (520 ) due to my own stupidity)

[gwcrim]

I had Gorr do my top end.  I even went with an over sized bore.  Isn't bigger always better?  I've been 100% satisfied with Eric Gorr's service.

[delusionised]

What do you guys know about porting and polishing?  How much more power does it really give?  Any recommendations on where to get it done on the west coast.  I live in vegas.  I am really getting tired of those darn 450's beating me.  I run mostly in the sand and I know my bike is faster but with my weight the 450's take me a just a hair.  I want to add more power but not really tear intot the motor because I want it to stay reliable and it seems like the more mods you do the more it breaks.

Thanks for any help!!

MIke

How much do you weigh? I weigh 248 and i race up against an 02 crf450 all the time and my buddy is around 200 lbs, when I was bone stock and so was he we pulled dead even on a road drag race, I then put a fatty on and vforce reed cage, I stayed with stock jetting and now I pull away, I let him go ahead and then I caught him and past him and he was nevergoing to see me again. I think 450's will run with ya until ya hit 5th and are on the pipe then they start falling behind, Dont ask me how cause we have mega torqe advantage and about 5-8 more peak horsepower STOCK! . Are you piped or valved? any way I wish you luck on smokn them bastads.

[mikesmith]

I cleaned up my own porting and suggest you talk to Doordie if you want to do your own,otherwiase try Pro-Circuit.

[Brett]

Just one thing on the porting side of things (ignore polishing as is just for dickywackers), i have seen a few dividers between main and auxillary transfer ports being knife edged which i have allways rounded rather than sharpened as flow is travelling up the transfers and as we all know the shape of a teardrop sureley this is the best approach.  I just actually cleaned up my ports last night and found the worst spot (best spot to fix) is the passage between where the reed block bolts and the main transfer port, there was tonns of casting flash here that required removal. The only other spot i thought was worth time on was the three passages between the crankcases and cylinder, these are an abrupt entry into the crankcase and also required rounding.  I was very surprised by the match quality of the main and auxillary transfer ports to the crankcase.  I am still yet to play with the exhaust ports but having a quick look reckon that there is possibly good cause to soften exit of auxillary exhaust passages(where powervalve drum seals off) as is a very sharp exit.  When i get down to a bearing store to buy my replacement pins for my powervalve i will get to have another play with the windy.

[99tjrockcrawler]

Thanks for all the info.  Who is Eric Gorr and where is he?  Does he have a website?  I tried a pro circuit pipe but it did not seem to help the top end just the low to mid.  I have a Reed valve from 1Dir Racing which did improve eberything.  I weigh about 250-255.  And I always lose to the new crf450r's.  Not by much but I can't pass him if he gets the holshoot.  This is always in sand topping out in 3rd if I hit 4th it bogs.  10 paddle skat trak.  How much about would a porting and polishing job cost?  Not worried about time as it is summer here and I don't do much riding in the summer.

Thanks again.

p.s.   Arigato...where do you ride most of the time?

[Arigato]

In the summer, we go to Coral Pink (June 17 is the first one) and Little Sahara.  Both are in Utah.  I also try to hit Mesquite and Glen Helen for a moto fix.  Come to Coral in June.  There will be some cool 500's:  2 custom KX's, 2 CR500AF's and 2 steel-framed CR500's.

[mikesmith]

You probally have the Pro Circuit MX pipe,there desert pipe will give you more mid/top end.

[doordie]

Look in "favourite mods" and "sticky part of rebuilding a top-end" by John!

//doordie

[99tjrockcrawler]

In the summer, we go to Coral Pink (June 17 is the first one) and Little Sahara.  Both are in Utah.  I also try to hit Mesquite and Glen Helen for a moto fix.  Come to Coral in June.  There will be some cool 500's:  2 custom KX's, 2 CR500AF's and 2 steel-framed CR500's.

We are going to coral pink next weekend (memorial weekend) for the first time.  Do you have to rejet for that area?  Where is little Sahara?

[Arigato]

You may have to lean her down one jet, but the sand is really soft so go in small increments.  Make sure you have buggy whips for all of the toys.  Little Sahara is about 2-3 hours north of Cedar City.  Both places are awesome....We stay away from both on the big weekends...Too many yo-yo's on the dunes with beer.  We wait until after the last ride to get hammered.

[Timbowe]

Looking choice there bro! Digin the XGx.