Hit back at the thumpers!

[Martin Cole]

A few weeks ago I posted a question asking if anyone had tried the carb vent system marketed by PC Racing. I had no replies but decided to fit one anyway. It's supposed to prevent bogging after long jumps and in corners.
We managed to get out today - first time for a month - to give it a try and the answer seems to be that it works well. Our YZ 125 wasn't lacking anything in acceleration out of the corners when the track started drying out but for the first few laps we were lacking traction as the snappy power delivery meant we had a lot of wheelspin.
All in all, I'd say it was well worth the investment and it could easily be worth two or three seconds a lap - enough to get back some of the ground the four strokes have stolen.
I'd still be interested to hear from anyone else who has fitted one of these kits to see if they've had a similar experience.
MC.

 

[oldfrt613]

All in all, I'd say it was well worth the investment and it could easily be worth two or three seconds a lap - enough to get back some of the ground the four strokes have stolen.
MC.

WOW - 2 or 3 seconds a lap !!!!!! Not exagerating there, are you ;) - I'm estatic when I can find something to get me 1/2 sec a lap.

 

[Rcannon]

Do you possibly have a picture of this vent system??? It sounds interesting.

 

[BMWPower]

Ya post some pics for us

 

[adam728]

http://www.pcracingusa.com/carburetorventsystem.php

 

[Masterphil]

Sounds like snake oil to me...
I've not yet had a problem with my 125 bogging or hesitating even in the rough stuff.

 

[crazy4nitro]

Sounds like snake oil to me...
I've not yet had a problem with my 125 bogging or hesitating even in the rough stuff.

I'll second that ...

Crazy

 

[MXP1MP]

It does help in the fact that it helps move the venting tubes up n out of the dirt like they are stock. I'm going to stop being lazy for once and do it to my YZ 125 I've noticed on really muddy days when the vent tubes get caked with mud. I've noticed an increase in the tendecy to bog the PC unit is just an nice easy way to do it. You can do the same just with some T vents and extra hose.

 

[Masterphil]

You can do the same just with some T vents and extra hose.

That's what I planned on doing before my first HS/enduro in the event of any water crossings.

 

[Martin Cole]

Hi guys - 2 or 3 seconds a lap obviously depends on how long the course is and the number of turns where you'd get any bogging. I can't say any more than we've tried it and the rider, my eldest boy, is really pleased with it. He's complained about it bogging down since we bought the YZ and although we leaned it off a bit on the pilot jet to make it pull sharper off the line it didn't cure the probem. Maybe its psychological but what the hell! If he thinks it's faster and more responsive I'll settle for that.
For those of you wanting to see a picture or two of how I installed the system, you'll have to wait till I can borrow a digital camera from someone. I'd guess there is a PC Racing website somewhere with the system advertised but I have to say it took a lot longer to fit than I expected. It was obviously designed for bikes that had plenty of room in the airbox and these days that's a luxury you don't get. I had to get extra tubing and mount a plate between the airbox and the frame cross member below the seat. This allows you fit the filter box in. The guy who gave me the kit had the same problem with his RM 125 - there was no room to install the thing as per the instructions - so he never bothered and it sat on his bench for a couple of years. He gave it to me and asked me to try it but because it was a real fiddle to fit it I didn't bother for a few months. Now I wish I'd done it straight away.
The tubing is just ordinary 3/16" windscreen washer piping and most auto shops stock it along with plastic T-pieces you need to make connections.
The real proof will be if we get an improvement in the results. I'll keep you posted - especially if we can stick it to the CRFs - and by that I mean the ones that normally finish just ahead of us.
We are still running a stock motor except for a DEP pipe and silencer.
MC.