Porting on a CR85

[Cody305]

What will porting a '05 CR85 do for the bike?
Someone in another forum said that this will not give the bike that much "more" power, that I'd be better off sticking the money in suspension. The bike handles very good now and it never looks to be getting "pitched" on jumps or bumps so...

I am currently running a DEP pipe and V-force 3 on the bike and haven't done anything else to it.

Race gas(Turbo Blue) & 93 octane pump gas blended 50/50 with Silkolene.

We race the series at Millville, and my kid is getting beat on the hills. For indoor riding this winter, I went one tooth bigger in the rear sprocket. It seems to help.

Any info would be greatly apprecited!

 

[TimberPig]

It really depends upon who does the porting and what kind of powerband you are looking to create. It could be set up to have stronger midrange, rev better with more high end power, or anywhere in between. Unless you know what kind of power you have ,what type you want and where it is lacking currently, you may end up getting a port job that doesn't produce what you were hoping for.

This article may help you determine what you are looking for, and what is involved.

2 Stroke Tuning

 

[bubbaxr]

Suspension is usually the first place you get some return for your dollars because it will enable the rider to go faster in conditions where he or she was previously having to back off to keep the bike under control. If the lad is at or near WOT and still slipping back a little each lap you may want to keep your ears open with respect to where the other folks are getting their engine work done. Now and again one comes across a combination of boring, porting, intake, and jetting that really hauls.

 

[Jasle]

if you still have stock suspension then your money is best spent getting the suspension set up correctly for your rider. not many kids use the power to its full potential but MANY are on bikes not set up for them. WE left our YZ stock and noticed huge improvments after getting the bike where he needed it. Got the right springs to get sag set right and set up rebound to his liking and he is way more comfortable. The 05 has much better stock porting than the 04-older so the mid range is better. You can get a slightly broader power band but I'd spend my money on suspension.

 

[Cody305]

We had the guys at Pro-Action of Mn go through the suspension last fall.
We switched to the Honda mid-season last year after racing a RM for 2 years before that.
My kids lap times at Millville dropped from the 2.40's to 2.20-30's. Over 10 seconds a lap better!
He says the bike doesn't get headshake like his Suzuki did, and we had the suspension completely done on the RM.(race tech)
Maybe just a better fit for him on the Honda, but I am hoping that porting the motor will give him a better chance of a top 3 finish.
We will reevaluate the handling when we can get back outdoors in March to see if we need to improve in that area as well.

Thanks for the feedback!

 

[Jasle]

porting will get you what you want out of porting. you can change port timing to get more topend but less bottom. less topend and more top. You should probably give Eric gorr a call and tell him what you want and he can then get it set for how you want it.