HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
dstark

Daves carb mods

22 posts in this topic

Anyone have any pictures of a drilled slide on an '06 XR650L? Where to drill and how big? A little nervous taking a drill bit to my carburetor.

Share this post


Link to post
Share on other sites

Pretty sure you use a 5/32 drill bit, very carefully, drill press if possible. Do a search for pictures there are lots out there, also a good video by :thumbsup: Dave :thumbsup: (doesnt show the drilling part).

Share this post


Link to post
Share on other sites

All the pics are over in the hoinda tech section at 4strokes . com.

But, its the 2 holes not in the center of the slide.

Dave

Share this post


Link to post
Share on other sites
All the pics are over in the hoinda tech section at 4strokes . com.

But, its the 2 holes not in the center of the slide.

Dave

What Dave said.

Plus, as mentioned, use a drill press, if at all possible. Make a couple of dry runs at the first hole to endure you are lined up properly. Whne sure, then slowly bring the press down to ream the first hole. Repeat for the second hole.

Ensure there are no burrs on the edges of the holes. Blow the slide off with compressed air.

You're done. (with this part of the mod).

EZPZ.

Share this post


Link to post
Share on other sites

Also, the holes are deeper than what I expected so a drill press really is the only way to go to ensure a straight, smooth bore operation. I did it to mine and can only tell a marginal difference. I've also re-jetted both jets (used the kit from Baja Designs that includes the needle and spring as well as the main jet). Replacing the main jet, needle, and spring made the most difference. Replacing the slow jet and drilling the holes cleaned up the remaining minor problems. As one of the others mentioned, there are several postings explaining all of this on this site as well as others. Main thing is to take your time and do it right.

Still think I'd like to get away from the vacuum slide and go with a cable operated model carb. Any recommendations? I'm searching this site for this. :thumbsup:

Share this post


Link to post
Share on other sites
A little nervous taking a drill bit to my carburetor.

Doesn't matter if it's new or old, beat or in good condition. These tweaks are the cure for this fickle & leaned out CV carb. Best part about it though is that it makes a big improvment over the stock set up :thumbsup:

These mods have been around long before the XRL. Problem is that this bike really suffers from the ultra-lean factory settings so rejetting is also necessary. Better have a service manual as well if you're planning on reassembling everything properly. :thumbsup:

Share this post


Link to post
Share on other sites

I'm having a bit of a problem getting the idle right. That Pilot Needle Jet Screw or whatever it's called I set to 2 1/2 turns out (with the tab ground off); but I'm having a tough time getting it to idle well, If I used the thing that sets the butterfly stop, it seems to either idle too high or too low (and die at a stop). I also removed the "snorkle" as well; I've been running a K&N and Big Gun exhause all along.

I also noticed that sometimes at steady high RPM; sometimes it seems like the fuel is cutting out intermittently. I didn't have this problem before with the stock jetting (but did get rid of most of the backfiring). I'm running 165 MAIN Jet and 58 Pilot Jet, needle shimmed, slide drilled (6ft Below Sea Level).

So which way should I be adjusting that idle screw?

TIA.

Share this post


Link to post
Share on other sites

dukeryder:

My neighbor and I have identical setups similar to yours. Only difference is we both have White Bros pipes and 55 pilot jets. We worked together and did the exact same things and same parts on both bikes. The two bikes ('06 XR650L's) run differently. Mine has problems problems similar to yours. Mike's doesn't. We had to play more with his needle adjustment than I did to get his to idle right. We started at the 2.5 turns and tried working in with 1/2 turn increments. We then went back to 2.5 after going in 2 turns with no improvement. Working out in 1/2 turn increments, I believe he settled on 3. His bike still has an occasional pop on deceleration but doesn't have that "running out fuel" sensation. We live in Galveston County and are about 16 - 17 ft. above sea level. :thumbsup:

Share this post


Link to post
Share on other sites

Guys, I'm knee deep into Dave's mods and am very concerned that the previous owner was into this before. No other Dave's mod evidence but the needle looks much different than the pic on 4 strokes. I don't know how to post, but my needle has no top. There is a spring clip or "C" clip a few notches down and there was already a washer. It appears that based on where the spring clip and washer were installed, it was shimmed way beyond the .020 - .030".

Not sure if i should be spring clip on top and use the new #4 washer from Radio Shack.

Please help, this project was way above my pay scale and now i'm concerned.

Share this post


Link to post
Share on other sites

Sounds like they used the DJ jet kit.

Did they give you any parts with the bike?

You could contact them and see if they have the stock needle.

Dave

Share this post


Link to post
Share on other sites

No shot at getting any past parts. The mixture screw had not been modified, the slide had not been drilled out to 5/32, but the jets are 58/155. I was going to put in 55/160

Not sure what to do with the needle.

Share this post


Link to post
Share on other sites

Well, the bike ran too rich, now i guess we know why, it has a non-stock needle that was shimmed way up. I raised the spring clip 2 notches and have 55/160. I'm going to put it back together and see what i end up with.

Share this post


Link to post
Share on other sites

Posting in old thread I guess is better then starting another one. :cry:

I am living in a country where they have chucked the queens measuring system and are using the easier metric one. :cry::ride:

I see the slide should be drilled to 5/32 inch which is equal to 3.96875mm

Do you think that it should be a problem to drill it to 4mm? Doubt that I would find a 5/32" bit anywhere here...

Share this post


Link to post
Share on other sites

I can't imagine making the holes 0.03125 inches larger would make any diff...

might be careful about that, .03125 happens to be exactly 1/32 larger...so an additonal 20%, might make more of a difference than you'd think.

Share this post


Link to post
Share on other sites

Do you think that it should be a problem to drill it to 4mm? Doubt that I would find a 5/32" bit anywhere here...

Hey I'm curious if you would want to do a trade? I would love a set of metric drill bits.. would you be interested in a trade for a set of SAE bits?

Share this post


Link to post
Share on other sites
I can't imagine making the holes 0.03125 inches larger would make any diff...
might be careful about that, .03125 happens to be exactly 1/32 larger...so an additonal 20%, might make more of a difference than you'd think.

The hole is not 0.03125 inches larger, its in mm. This is only about 1.6% larger in terms of area. I doubt Dave determined the proper hole size to that level of precision. For what its worth, before I moved to an FCR carb I did Dave's mod on my CV carb with a 4 mm drill, it seemed to work fine.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0