FCR MX Slide Roller Replacement

[odyssey]

Hello all, 

I appreciate the help this forum has given me over the past couple of years. I recently picked up an '01 DRZ400s and decided to do the FCR carb swap. I feel pretty confident that I managed to read almost all of the valuable threads regarding the CV to FCR swaps on this forum and others. 

Being a fairly competent mechanic, I opted to pick up a local FCR MX off of a YFZ450 from Craigslist. I've rebuilt quite a few carbs and I feel like I now have a greater appreciation for why the experienced group recommends people go for the new FCR swap kit or something that's off of a validated running bike. There are so many moving parts inside of the FCRs that are prone to wear, the margin for issues can grow pretty large. It was my first time inside of one, so I know for the future. 

Regardless, I have a used MX that was worked on with heavy hands and I'll do my best to make it run for me. Moving parts are in pretty fair condition as far as I can tell, but I'm having some issues with the rollers on the slide. There are 3 rollers which are fixed with bearings and 1 that's removable. 2 fixed ones with bearings have a little drag and you can feel that the bearings have some wear. It's not terrible, but I'd like it sorted while it's opened up. 

Prior to replacing a slide, my questions are:

Could these bearings be gently removed and replaced with the rollers that don't have bearings? https://www.jetsrus.com/individual_parts/021_027_su.html

Are there replacements for just the sealed bearings? I assume you'd have to take measurements and just find aftermarket ones, which is likely not worth it at all. 

Has anyone found any good tricks for cleaning these bearings? I believe they're sealed, which is generally a tough one to fix. I've heard of people soaking sealed bearings in solvent for 24 hours and then heating the bearing before spinning the solvent out. 

Thanks for your help,

 

[S.O.A.N.Z]

Flick the cap off & take some bearing measurements - see if you can match something up

[odyssey]

Thanks, SOANZ. My head went there too. 

Since I don't have small precision pullers I think I'll support the bearing from the bottom with thin metal plate and tap the 'axle' shaft with a small punch.

[S.O.A.N.Z]

2 minutes ago, odyssey said:

Thanks, SOANZ. My head went there too. 

Since I don't have small precision pullers I think I'll support the bearing from the bottom with thin metal plate and tap the 'axle' shaft with a small punch.

Yeah something like that   ?

[odyssey]

I always appreciate a good follow-up so I'm returning to report my failure. 

The bearings were very difficult to fixture due to the minimal clearance between them and the slide so I opted to carefully pry them off. The shaft that the bearing rides on is not integral to the slide body, but rather a steel (I think) shaft that's pressed into a hole. The fit was tighter between shaft and bearing than shaft and slide so the shafts came out with the bearings... so I was kinda shafted.  

Upon close inspection, I could see that even gentle prying around the edges caused the hole to expand and lose concentrically. The bearings appear to be 3mm ID x 4mm width x 10mm OD, which is standard. I think that if you really wanted to do this it could be done should you fixture it just right, but it's probably a waste of time. I'd recommend being patient and sober too. 

I bought a used slide on eBay for $40 shipped and the seller said the rollers spun freely - if I'm not satisfied he'll take it back. 

[S.O.A.N.Z]

It was worth a shot 

[Greg 4stroke]

Hi there, thought I'd share my experience with fcr mx throttle slide rollers.

Firstly would one roller be bearing less for a purpose? Can't imagine Japanese engineers doing it? My slide body is worn mostly where this roller is. What is more it's slightly smaller in diameter then the rest ~0.4mm. I thought mine was worn due to lack of bearing, but to my surprise a brand new spare came smaller too. It's a tiny difference, but big enough to make the whole slide rocking. I'm now tempted to fit a bearing there too. Just can't find a good used slide to merge two into one. Couldn't find a new one, but if there is one it will most likely cost arm and leg. Let me please know if you know a good source. 

Thanks Greg

[William1]

That is a great question, why is one roller 'bearing-less'. Makes no sense to me. I could make speculations but I'd have a hard time convincing myself.

I have to wonder if a wider bearing could be used and be all metal with no plastic 'rim'. The wider contact area should yield less wear as the load is spread out over a larger area.

The is a guy in Europe I think that sells ever so slightly wider plastic wheel to ride over worn bodies, but that will only give you a little time. Worn bodies must be resurfaced, with epoxy and then milled flat.

[Greg 4stroke]

It stills works well, but I'm afraid that wear will deteriorate quickly now. On a hunt for a 2nd hand carb to pull the slide. Trouble is people reluctantly supply pictures of the interior. Anyway I'm from UK what place in EU you had in mind? The best source for keihin I know of is Frankmx in Netherlands...

[William1]

1 hour ago, Greg 4stroke said:

It stills works well, but I'm afraid that wear will deteriorate quickly now. On a hunt for a 2nd hand carb to pull the slide. Trouble is people reluctantly supply pictures of the interior. Anyway I'm from UK what place in EU you had in mind? The best source for keihin I know of is Frankmx in Netherlands...

I do not remember, but... it was in the last few weeks. If I find it, I'll put a link to it here.

[William1]

Found them: https://www.rege-carb.pl/index-uk.html

I am a bit skeptical and I'd like detailed information regarding how they restore the carb body. It seems to my feeble mind that with the right epoxy and tooling, there is no reason you should not be able to restore the carb. But until I see the job, it would be buyer beware. I do think it could be a worthwhile business for a small shop. Loads of worn FCR's out there and still in demand. Certainly worth say, $400.00 for a truly restored to 100%, good as new carb vs buying new for twice the price.

[blittlej]

22 hours ago, Greg 4stroke said:

Hi there, thought I'd share my experience with fcr mx throttle slide rollers.

Firstly would one roller be bearing less for a purpose? Can't imagine Japanese engineers doing it? My slide body is worn mostly where this roller is. What is more it's slightly smaller in diameter then the rest ~0.4mm. I thought mine was worn due to lack of bearing, but to my surprise a brand new spare came smaller too. It's a tiny difference, but big enough to make the whole slide rocking. I'm now tempted to fit a bearing there too. Just can't find a good used slide to merge two into one. Couldn't find a new one, but if there is one it will most likely cost arm and leg. Let me please know if you know a good source. 

Thanks Greg

 

Edited February 18, 2022 by blittlej
question was answered early in thread.

[Greg 4stroke]

17 hours ago, William1 said:

Found them: https://www.rege-carb.pl/index-uk.html

I am a bit skeptical and I'd like detailed information regarding how they restore the carb body. It seems to my feeble mind that with the right epoxy and tooling, there is no reason you should not be able to restore the carb. But until I see the job, it would be buyer beware. I do think it could be a worthwhile business for a small shop. Loads of worn FCR's out there and still in demand. Certainly worth say, $400.00 for a truly restored to 100%, good as new carb vs buying new for twice the price.

Check this guy out. I bought quite a few spares there. https://www.frankmxparts.com/epages/62910900.mobile/en_US/?ObjectPath=/Shops/62910900/Products/2724&ViewAction=ViewProduct

[William1]

12 minutes ago, Greg 4stroke said:

Check this guy out. I bought quite a few spares there. https://www.frankmxparts.com/epages/62910900.mobile/en_US/?ObjectPath=/Shops/62910900/Products/2724&ViewAction=ViewProduct

[William1]

@Greg 4stroke I tease.

FrankMX has a stellar rep. I'd like to see what his solution is. The shame is there are a lot of riders who ride at low RPM, and only use the bottom third of the carb and so get excessive wear. The downside to wheels moving over a short range VS a 'slide in a bore of Yore'.

[Greg 4stroke]

21 hours ago, William1 said:

@Greg 4stroke I tease.

FrankMX has a stellar rep. I'd like to see what his solution is. The shame is there are a lot of riders who ride at low RPM, and only use the bottom third of the carb and so get excessive wear. The downside to wheels moving over a short range VS a 'slide in a bore of Yore'.

That's true. I found him on eBay and then his online shop. Since then always shop directly. He even created a listing for me for a single Venturi insert seal out of a kit the same day so I could order in the evening. Had a few shipments to UK. Always within or under 5 days. Top guy.

[bumtarder]

On 2/17/2022 at 1:54 PM, William1 said:

Found them: https://www.rege-carb.pl/index-uk.html

I am a bit skeptical and I'd like detailed information regarding how they restore the carb body. It seems to my feeble mind that with the right epoxy and tooling, there is no reason you should not be able to restore the carb. But until I see the job, it would be buyer beware. I do think it could be a worthwhile business for a small shop. Loads of worn FCR's out there and still in demand. Certainly worth say, $400.00 for a truly restored to 100%, good as new carb vs buying new for twice the price.

I emailed him about his services and unfortunately they do not offer services on this side of the pond. So, we may never see or review his work. That only leaves FrankMX's slide roller repair kit at this time for the masses unless some enterprising machinist metal epoxies the raceway and resurfaces it back to stock. Alumalloy and Diamant Moglice may or may not work either, haven't heard of any success there or the practicality of it for a FCR.

[William1]

5 minutes ago, bumtarder said:

I emailed him about his services and unfortunately they do not offer services on this side of the pond. So, we may never see or review his work. That only leaves FrankMX's slide roller repair kit at this time for the masses unless some enterprising machinist metal epoxies the raceway and resurfaces it back to stock. Alumalloy and Diamant Moglice may or may not work either, haven't heard of any success there or the practicality of it for a FCR.

I've heard of a few backyard guys epoxying it and then smoothing it out with a file, but never seen the end result or heard long term test results.

I find it hard to believe (and not doubting you at all) a company would not want to take your money if you shipped them your carb. Who turns away paying work? I've done plenty of transactions via email with companies located all over the world, even those that spoke no English and me not speaking theirs. Makes me wonder about the true value of the services they offer. Perhaps a local guy will stumble on this thread and chime in.

[bumtarder]

Me either. It seems to me that there would be a lucrative market for those types of repair.

This was his response;

Hello,

Do you offer these services and shipping to the United States?

 

 

Paweł Marecki

1:09 PM (2 hours ago)

to me

Hi, unfortunately no

 

Best regards 

 

 

Edited February 19, 2022 by bumtarder

[Greg 4stroke]

3 hours ago, bumtarder said:

Me either. It seems to me that there would be a lucrative market for those types of repair.

This was his response;

Hello,

Do you offer these services and shipping to the United States?

 

 

Paweł Marecki

1:09 PM (2 hours ago)

to me

Hi, unfortunately no

 

Best regards 

 

 

Not sure why they wouldn't send if all the costs are still with buyer? Try asking if they could at least send wider rollers? To be honest getting them made doesn't sound like a big issue. They are made from either PA, Delrin or similar? Same diameter as stock just wider. Most likely wider both ways, outside and towards the slider body to run over the worn groove. Any machine shop can do it just get them a right drawing. Of course it depends on the wear.