uncorking my BRP today! March 18, 2012

Guys I am very happy with the HRC carb upgrade on my pig but I still have a problem, anytime the bike is cold and I go to a stop light the bike start backfiring and want to shut off, I need to rev it all the time also when I am taking off if I don't rev a couple of time before I take off it will die on me. Any suggestion on what to do? should I change any jet for a bigger ones? please don't have experience with carb, any help will be appreciate it. I want to make a video riding the bike I will try to post it so maybe you can hear what she does if no I will have to take it to the Honda dealership which I really don't want to but I will like to do a valve adjustment anyway so I may end it up bring it in.

When I fitted my exhaust HRC tip my bike started back firing on de-acceleration....moved the clipt o position 4 and it's now virtually gone...still get the odd pop but not very often.

OK BM,

here goes what I would do.
- check valve clearance first, and make sure all's honky dory
- take carb off, disassemble fully & clean, with compressed air! A forceful blowjob is... you'll get it, it'll do the job
- that choke-flap is out innit? If not chuck it, screw, spring & flap, the lot, file-19 it!
- adjust the float level to 19mm (yip, up by 1mm) - and you know you have to do this whilst turning instead of simply turning it upside down? Whilst turning, ie during turning, blow through a piece of fuelline to check it.
- then assuming you did put in all the recommended parts, with the clip on the 3rd groove of the correct needle, set the idle screw (mixture screw, not the slide-stopper!) to 1.5 turns
- put carb back
- screw-up the slide stopper a bit
- start
When running the idle-revs probably will be a bit high. Trun back a bit, leave a bit highish, and let piggie come up temp. Then, adjust the mixture-screw either way to find highest revs - and, to prevent overheating, run a waterhose over a radiator during all this.
When this highest revs point has been found (a little turning either way should give you this!) reduce the revs by turning the slide screw down - and repeat finding highest revs by turning the mixture screw again, but less either way this time.
Then again, reduce the slide screw until you have a normal idling revs.
Kill engine, remove hosepipe, kit up, and start again to go ride, it'll be fine!

burp it sounds too complicated, when you said take the carb back down and adjust it to 19 mm from where is the measure of the 19 mm?

Top-of-float to gasket-surface of the carb housing, without the gasket, measured square to the carb's surface.
Blow through the petrol pipe whilst turning it upside down until the flow stops aka the needle seals off the seat. This is the angle you measure at, and the above mentioned distance should be 19mm.
Slightly bend the metal tab of the float-assy so as to obtain this distance.
Measuring with a vernier or sighting a steel ruler over the floats will work fine.

Why 1mm more than the book's 18mm? These carbs have a tendency to overflow when leant over on the sidestand, and this +1mm is said to cure this as in effect you drop the fuel level by 1mm. But also, it is just very little 'off' from the prescribed setting, it won't affect things too much - and you're going to adjust the idling as er above anyway.

Oh BM,

please, ZERO offense, but obviously you take off the floatbowl first, with gasket.
Read my lot when you have the carb in front of you, it'll make more sense that way.

If you knew all this already have a coffee/beer/whiskey and forget I ever wrote this

Do yu hav an air leak on the intake or the exhaust?

Thanks BURP, I had taken the carb off already like 3 times but I can do it again if it will solve the problem.

Aurora, No leaks That I am aware off but I can double check. I did a tried my mini MD80 yesterday I will see if I can post the video, the camera was too low aiming to the street, I will do another run leater this afternoon and see if I can posted in you tube I guess.

BuRP wrote:Oh BM,

please, ZERO offense, but obviously you take off the floatbowl first, with gasket.
Read my lot when you have the carb in front of you, it'll make more sense that way.

If you knew all this already have a coffee/beer/whiskey and forget I ever wrote this

Ok guys, I just uploaded a video from yesterday after the rain I took my BRP for a ride, Here is the link it is my first video so don't complaint, there is no music only the sound of the BRP, enjoy

https://www.youtube.com/watch?v=Yr-KBBNxP2g

bikerman wrote:

BuRP wrote:Oh BM,

please, ZERO offense, but obviously you take off the floatbowl first, with gasket.
Read my lot when you have the carb in front of you, it'll make more sense that way.

If you knew all this already have a coffee/beer/whiskey and forget I ever wrote this

Ok guys, I just uploaded a video from yesterday after the rain I took my BRP for a ride, Here is the link it is my first video so don't complaint, there is no music only the sound of the BRP, enjoy

https://www.youtube.com/watch?v=Yr-KBBNxP2g

Can't get the YouTube link to work on my IPad.

Did you do this:


Make sure your engine is fully warmed up and set the pilot screw to 1.5 turns out. Then with the 68s installed, turn the pilot screw clockwise until the idle slows. Then turn the pilot screw counterclockwise until the idle slows again. Make a mental note of how many turns you made in between the low idle points. Then turn the pilot screw half way between the low idle points to finish the adjustment. If you turn the adjuster counterclockwise and the idle doesn't drop down, then you need a larger pilot jet. If you turn the pilot screw clockwise and the idle doesn't drop down, then you need a smaller pilot jet. After adjusting your pilot circuit, re-adjust your idle speed if necessary.

This video is private.
Sorry about that.

Come on don't be shy share the video

BM,

if this won't do report back, but this will solve any carb's idling settings you care to mention.
Start bike, let it idle until the choke can be turned fully 'off'.
Allow a little more time to warm up.
Set the idling revs (the screw on the slide) a touch higher.
Adjust the mix-screw either way until it wants to die off, and set it smack-bang in the middle of that range - this means keeping track of revolutions, but you know that.
Reduce the rev's (by turning down the slide screw again).
Again turn the mix-screw either way, but less this time, and set it to the middle of the 'sweet spot' - which will be the highest rev's, however more not so much noticeable as it is audible. Cock yer ears bru, and stuff any chickens
Set the idling revs to what you prefer.
Done.

NB: this 'done' is when the mix-screw is neither too far in our out, but with your 68s this will be the case.

Thanks Burp and Mausser, I will work on it. This is my first time I upload a video to youtube but if you have the link I did send you guys you should be able to watch it. may be tomorrow if I have time I will change it to public. Sorry guys!