drca

Great. Can you tell me what hub / bearings you used?

Yep, that's what I tried to explain (sorry I wasn't clear enough), but I can't find the part number for the hub only. So I don't know if the hubs are the same.

I scored a complete Tech Fork setup for a reasonable price to replace my Marzocchi (which has scratched and bent tubes...) on my 2013 TXT Pro. The setup comes complete with the fork, axle and triple clamp. The front wheel axle on the Tech is 20mm vs 25mm on the Marzocchi. I assume the front hub on the Gas Gas are the same whether they are used on the Tech of Zooch and only the bearings and spacer change (and with the addition of a spacer on the brake rotor). From what I have seen on the 2013 TXT Factory Replica Gas Gas part list (which has the Tech fork), the front bearings part number is C160001 which look like 6004-2RS (20 x 42 x 12). Which would mean, again if the hubs are the same, that they will stick out of the hub by 3mm on each side (the bearings for the Zooch are 25 x 42 x 9). The only other alternative that would fit are the 98204Y-2RS (20 x 42 x 9), which are hard to find and rather pricey! So I was wondering if anyone could confirm: 1) That the hubs are the same for a Tech and a Marzocchi fork? 2) What bearings are used for the Tech fork? 3) if the bearings are indeed 6004's AND the hub are the same that the bearings aren't flush with the hub and stick out 3mm. Thanks. DC

Thanks for all the answers (altho I didn't get the piece of string reference...). The 400 hours is based on riding 3 times a week for about 1.5 hours of bike running per session for about 30 weeks a year. Maintenance wise, here is what has been done: when I bought the bike I took it completely apart and even stripped the frame to the bare metal to inspect and have a few issues fixed: dings in the upper frame tube, rear engine mount cracked. I had the frame, swingarm and fork bottoms powder coated. I rebuilt the rear suspension (all bearings, bushings, seals and fork (seals, bushings, oil change) and the steering bearings. Rebuilt the front and rear brake calipers with new seals all around, new pads too. Then the usual new grips, folding lever, ban ends, chain and sprockets, new air filter, cleaned (ultrasonic) and rebuilt the carb, new reeds (carbon), new sparkplug, and new plastic and sticker kit all around (I recommend the Jitsie rear fender - indestructible!). Since that initial work, I have changed the bash plate and rubbers twice a year (yeah, sportsman rider here!). I check the wheels and rim every time I change the tires (see my other post on corroded rear rim). Wheel bearings are fine, but since they are cheap I'll probably change the this winter anyways. The rear engine mount cracked again (other one), so I had that fixed too. Engine wise I rebuilt the water pump, changed the radiator (bad fall!), fan (whinny fan syndrome due failed bearing) and the hoses (silicone ones). I had to change the clutch basket / main drive gear (see my other post on that, my mistake, the thrust bearing fell in the engine when I put the side case back). New kickstarter seal. I have a brand new exhaust (full set that I got from a guy who turned a brand new bike into an electric one) that I'll probably put on at one point, maybe this winter. Things to do this winter: full service (break it down to the frame, check and lube all the bearing and seals, replace the ones need replacement), new grips, fluid flush (coolant, brake, clutch), new fork (I bent the Marzocchi and I just bought a used Tech in like new condition), probably new rear shock (Ohlins). New wheel bearings, new bash plate and associated rubber pads. Switch from the Dell'Orto to a PWK (carb, intake manifold, reed box, cable). New clutch plates. Probably new clutch pedal (current one is wobbly and has been bent a couple of time). I'll probably throw in a new piston and rings too while the engine it out of the frame. Full bottom end rebuild will probably wait another year... Thanks again for the help.

I have a 2013 TXT PRO 250 that I purchased used a couple of years ago with unknown number of hours. I probably put 400 hours on the bike since I bought it. I am wondering how many hours these bikes go before needing a top end rebuild. It's running fine, but it feels easier to kick than when I purchased the bike (which just might be me getting used to kicking it...) I haven't measured the compression yet, but I could do that if someone tells me what numbers I should expect from a compression test (and how to measure: carb on / off, reed box on/off, pipe on/off etc...). When doing a top end rebuild, what's needed (beside the gaskets)? Rings only? Piston? Thanks. DC

I have a 2013 Gas Gas TXT Pro Racing with the flanged rear tubeless rim. I change my rear tire regularly but it seems that I am always in a hurry and never take the time to correctly inspect my rim when I do it. Well I have been having a slow pressure leak in the rear recently that became worse yesterday so I took the rear wheel off the bike and hunted for air leak with my bottle of soapy water. Turned out that there was some small rocks embedded between the rim and tire and most of the air was coming through there. But there is also a very small leak at the valve level (at the interface rim / valve). Is the tubeless valve on these rims the same as the automotive type or are they special trials rim version? So I took the tire off the rim and decided to clean up the tire were it makes contact with the rim as well as the rim. Well, I am sorry I didn't take photos of the rim before but after I cleaned it up with a wire wheel and sanding pad discs, here is what I had left: There are some pretty bad corrosion with flakes of alloy coming off... Is that common? What can cause that? Thanks. DC

My advice... take the whole thing apart and check all the bushings and bearing, grease or replace as appropriate. Not sure where you ride (dry or wet) and when was the last time you serviced the suspension linkage, but that should be a regular maintenance item on these bikes (once a year minimum). And while you have the shock and linkage off the bike, might as well take and extra 15 mn to drop the swingarm and grease / replace the bearings there while you are at it

I thought I had the video it bookmarked, but apparently not. I searched youtube for "JIm Snell Dell Orto" and the only video I could find was his video on the Dell Orto carb (very useful but nothing on the tuning of carb). From what I remember seeing in the video I am still looking for, the procedure was as follow: Warm up the engine Turn the iddle down at the limit of stalling Crack the throttle open fast If the engine bogs, adjust the mixture screw Repeat until happy with the result. Now... I can't remember which way to adjust the mixture screw function of the result of cracking the throttle... Thanks again for all the help.

I have a 2013 250 TXT Pro with the Dell'Orto carburator. First I was surprised to learn that the mixture screw is actually a fuel screw and not an Air Screw. Now, concerning fine tuning of the fuel screw, what's the standard range of turns? Jim Snell had a video for adjusting the screw but I can't find it anymore. Any other guides / recommendations for doing that? Thanks. DC

Agreed, just wanted to know if a 2014 type radiator would fit on my 2013. I ended up going for a used unit from Trials Bike Breakers for £100 and £40 for the fan. I'll probably look for a US place to fix my radiator. The other alternative would be to get one of the low cost (cheap?) Chinese version on eBay... They go for $100 (for the radiator) including shipping.

I busted my radiator and fan on my 2013 TXT Pro Racing. So I am looking for a replacement. These things are expensive!!!! My radiator looks like this: I was wondering if anyone knew if the 2014 radiator would fit on a 2013. The main reason is that on the 2014, the filler cap is smaller and on the side (which with all the wiring crap under the tank has to help). Thanks.

I screwed up and now I need help to fix my mistake... It all started with a crash and loss of clutch pressure at the lever. It took me a while to diagnose it to a pinched (and punctured) hydraulic line: the line got pinched between the frame and the lower triple clamp dring the crash. In the process of replacing the clutch line I decided to change the hydraulic fluid and "upgrade" to DOT 5.1 (which is compatible with both the oil and brake fluid systems). So to do that I took off the right side engine case to flush the clutch slave cylinder. Since I had changed the oil recently on the bike, I just laid the bike on the left side and proceeded with taking off the side case, flushing the old fluid, replenishing with DOT 5.1 and put the case back on the bike. Then I put in a new clutch line, took the master cylinder apart and cleaned everything, filled up the system with DO 5.1, bled it and off we go. Fired up the bike to make sure it worked, no problem, good to go riding the next day. The next day, take the bike off the truck, fired it up and... clunk clunk cluck goes the engine So right there in the parking lot and lay down the bike and take the clutch side case off and what I saw was the clutch need thrust bearing and washer laying at the bottom of the engine. What I think happened is that then I put the case back on, the washer and thrust bearing must have slid down the slave cylinder and fallen off in the engine main cases. For some reason nothing happened when I fired up the bike after putting it back together, but the next morning all hell broke loose. Here is what the thrust needle bearing looked like (not bad, just a couple of needles dropped off): So yesterday I took the engine off the bike and carefully drained and strained the oil, opened the clutch side case, took the whole clutch assembly apart and looked for damage. I found one of the needle stuck to the magnetic fill up plug 1/4 chewed, and a bunch of metal "dust" on the clutch assembly. I flushed the whole engine several time with gas and didn't see anything else coming out. I put everything back together today, filled up with oil, fired up the engine and here is what I got (video). Not good. It's a little better when I pull the clutch but not much. So I took the engine case off again and it looks like I have some play in the bearing primary shaft: when I push it side to side I can definitively feel and hear some movement. Here and here are a couple of videos. I inspected the teeth on all the gears and there is only superficial scratches on them. So... Looks like I'll need to split the cases and replace at least the primary shaft bearing. Hence, here is the question: How complicated is that? What special tools are required if at all? How much would a shop charge if I were to take the engine to them to do this (not including price of parts of course)? Thanks for the help.

In this video interview from Marc Colomer at the end they show some details of Jaime Busto factory bike. Here is an interesting one: That is one BIG spacer... Looks like extra weight too. Any idea what this is for?

Ok... I found what the problem was. My issue started when I looped the bike a week ago and it fell pretty hard on the right side. Then it got worse last week when I dropped it again, same side (maybe I should work on not crashing so much). Turns out that the clutch line got pinched (and punctured) between the lower triple clamp and the frame when the bike landed on its side. Air got in the line at the puncture point, causing the loss of pressure at the lever. With the air in the line, pumping the lever didn't flush any fluid out of the line at the pinched point so there was no apparent fluid leak, making it hard to diagnose the problem. But it all became apparent once I started pushing new fluid through the bleed nipple and saw the fluid leaking from the line. Usually the line is routed inside the frame which should prevent this problem, but last time I took the front end apart I just re-routed the line outside the frame for expediency... my mistake. Good thing is that I had a spare clutch line (too many project bike finally paid off!). So all is good now. Thanks again to all for the help.

Will do. How do you insure that there is no air bubbles below the nipple down in the slave cylinder? Just tap and pray that the bubbles will move up?

Yeah, I think it might be time to do a rebuild on both the master and slave cylinders. Does anybody knows the rebuilt kit part number for the slave? (2013 TXT Pro - Mineral Oil). Thanks for all the help.

I think any hydraulic fluid used by any shop that services hydraulic things should work.

When I take the lever off and push the cylinder by hand, I have no pressure buildup (just the push back from the internal spring). Master cylinder reservoir is full... I haven't try to push fluid from the slave side yet to see if any bubbles pop up at the master side tho. Denis

Ok, Saturday I had some clutch problems that I attributed to air getting into the system after looping the bike (inconsistent clutch engagement, etc...). So Saturday night I took the master cylinder apart, didn't see anything wrong, but just in case replaced the whole assembly by a spare version I had (altho that spare I was reserving for a project bike and was NOT a NEW unit and had an unknown history). Put the master cylinder back together, connected to clutch line and pushed some new fluid though the nipple at the engine case level and after a bit of fiddling all seemed good. (I didn't have any hydraulic fluid handy so I used 5W fork oil with the plan to flush the system with the proper fluid when I get some.) I went riding the morning, and I dropped the bike (just dropped it on the right side). And when I picked it up... NO CLUTCH! Pull at the lever required almost no force and when pulling the lever nothing happened (clutch did not disengage) There is no apparent fluid leaking around the master or slave cylinder. I took the lever off and the cylinder still moves back and forth but it seems that the only force I push against is the one from the return spring inside the cylinder. When I took the cap of the master cylinder it was full (or close enough considering the space the membrane takes), and when I pump the lever I cannot detect any fluid movement (or bubbles) My diagnostic is that the conical seal on the cylinder has failed and that I need a NEW rebuilt kit. Anyone has had similar experience? DC

Probably, but since I was in a pinch, fork Mineral oil works fine (well, I still have clutch problems... see new post on that).

Thanks! That's what I figured out, green bladder so I went out and used 5W fork oil (couldn't find my Magura bottle from my KTM days). DC

I need to bleed and probably flush my 2013 TXT Pro 250 clutch line (engagement has become inconsistent after I looped it, so I think air got in there). The previous owner replaced the clutch (and brake) master cylinder caps by nice S3 anodized ones, which doesn't help in telling me what's in there. Is there a way to make a difference by looking at the fluid? And what's the best way to bleed these things? Push fluid through the bottom with a syringe? Thanks. DC

Yep, 98204Y will work tho (20x42x9). This is getting way too complicated tho... (and expensive!)

Thanks! Here is what I understand: Wheel bearing The Tech Fork has a 20mm axle vs the 25mm on the Gas Gas. So I need to drop in some 6004 bearings in the Gas Gas wheel. Bearing spacer I need a new bearing spacer with an OD / ID that will match the 6004 bearings Wheel Axle I'll need a Tech Axle Fork clamps I'll need adapters to go 40mm to 39mm for the top and bottom clamp (4 of them - I think I saw these somewhere online...) Wheel spacer Not sure if I'll need any spacer to set the wheel centered in for fork and to align the brake disc with the brake caliper. Anything I am missing? Thanks!

My zooch is getting pretty beat up (bent sliders, several nicks in the sliders, starting to leak oil...). So I can either keep fixing it (which range to fill in the nicks in the sliders with the usual mail polish trick and replace the oil seals to getting new sliders), but I found a tech fork for a reasonable price. So I am wondering what would it take to put that tech on my GG. Here is my list of questions: Tech is 39mm, Zoock is 40mm, but I know there are adapters Front brake (tech are usually using the braketech setup, mine has the older AJP (?) Will that fit in? Wheel axle - Will the stock GG axle fit? Wheel spacers (that I can probably get made or buy) Am I missing anything? Thanks.