in my opinion one of the best, accurate, detailed, diy carby rebuilt and explanation video, by a long shot. well done! i keep coming back to this video just so i don't forget anything on my carb rebuilds.
Though I’m an rc airplane guy, I enjoyed your excellent video. The non-serviceable inlet is the “seat check valve”. The other side has fingers crimped in holding a little disk. They do go bad, and it’s fairly easy to destroy one with a blast of air or carb spray. They are “non serviceable” in the sense that Walbro has discontinued those parts, but you might find old stock on line. Old one can be removed with the right size screw or the Walbro tool kit once contained a punch. Some models also had pressed in ‘nozzle check valve’ which had the crimped end in the throat of the carb as part of the main jet. If damaged, at idle there is vacuum on the idle port because it’s inboard of the throttle plate, but there is not enough flow through the Venturi to create vacuum at the main jet- so the idle jet might pull some air in through the main jet instead of drawing fuel from the metering chamber… erratic/unstable mixture at idle. Anyhoo, can’t really blame Walbro for discontinuing those parts. I think most of their business is from power equipment repair shops, and no one is going to want to spend $22 for rebuild kit, like $80/hour shop rate- and maybe end up with a bad and not available check valve. People either get a new (or knockoff) carb, or in the case of a cheap string trimmer- throw the whole machine away
Nice job Mark. thank you! This step by step video was essential for a WalBro Carb rebuild on a 25 year old VARIO ALOUETTE II 1:6 scale RC helicopter. I’m now Celebrating with a smooth idling engine after …… well…… 10 pulls. What a difference! Idling like never before. Side note: As I didn’t have profi punch tools needed for refitting the Welsh washers (?), I used similar sized hex drivers….. with success! I did struggle with the smaller copper fitting … mine did not come out as easily as yours. Beware. Flying this coming weekend. Regards from Switzerland
Loved the info you gave us in this video. Taking the time to explain everything pertaining to the functionality, which is very important to having a running work on carb in the end. Finally I got to see behind those welsh plugs. Thank You.
Hey Mark. Nothing but boring is the video. It is awesome. Great pro work again my friend. It is by far the best video for carbs. You are the leader. Keep going man.
Thanks George! I thought for sure it would have been too boring for everyone! Mate its winter here now, wish I could be over there racing in the sun with you boys!!
20:55 just in case everyone wasn’t paying attention this is the critical moment in the video where we learn how to address a lean/rich carb AND CORRECT IT without the official Walbro W tool
Awesome. Good video. Pls let me know which bearings I need for wt603b. I will start rebuilding 10 carbs which bit I need to bore out carb bearing hokes
Mark thank you so much !! The best explained carb function ever :) I am repairing my old chainsaw and I now finally understand how these small carbs work! Cheers , Z.
very good video I'm looking now to understand better to make a perfect adjustment of the carburetor and explain the features of the high and low of the needles how to adjust for start and end of acceleration thank you very much
Hola. Saludos desde chile. An pasado años desde que hiciste este video. Pero te agradesco igual. Me estás ayudando a entender este nuevo mundo RC 1/5. Saludos y muchas gracias
Just found this, awesome, any word on when the bearing mod video will be up. I have a small lathe and mill so I think I can certainly start doing that on a carb I am about to rebuild
Thanks for the video,very helpful. But i have a question. What drill did you have for drilling out the bearings. Partnumber of link would be very nice. Best regards
Great video!thank you! Hope you can help me. If i pump my primer bulb air goes out but no fuel comes inside . I already changed all gaskets and diaphrams and screen with walbro rebuild kit and used air compressor in every hole. Should i try to remove the welch plug?? Thank you
What size rotabroach were u using mark Solid explanation of carb workings etc Have u thought about doing the metering mod where essentially u take about 3 coils from each side of the metering spring to bring the pop of pressure down to 16psi Regards
Hello. could you give my walbro wt668 a review ?? I really like the improvement of the bearing on the throttle shaft, just with that, my carburetor would last a lifetime, hehe.
Mark great video! I need help with someting you did not cover though.I got a used old weed trimmer with a carb. almost exactly like yours, however under the primer there no orange ring like yours. Is that something that should there? I can't get it to prime?
Brilliant video, would love to see one on a 990 and the bearing mod too! The small welch plug in your carb doesn't seem to be present in mine, I whacked it a few times and it's solid.
You filled a great niche, your instructional videos on RC motors (I'm into GoPeds) exists nowhere on this platform other than on Derek Short's channel. Although he will always be leagend your vids are so much more clear and we'll edited.
Great video, thanks! I have same car, CY 24cc when I got it, it started up immediately. Then it was sitting on the shelf for few weeks before going to the track. There it just did not want to pump fuel and barely get it going. Now I rebuild the carburettor, pressure tested it and it is ok. But the motor still wont run. L needle is 1,25-1,5 turns. I managed to get it going for few seconds if I remove fuel intake line. Motor has spark, carb does not have a choke. Can you give an idea what to do?
I am rebuilding a Zenoah 230RC1 for my Gasser Helicopter, and i knew nothing about these engines, but your great videos are helping in the extreme, keep it up, and can you do on on tuning? P.S. i love the music you chose!
Gday Mark best video on TH-cam explaining the carby... and believe me I have watched thousands. Would you have a part number for the milling bit you used and are they 5x9x4 bearings wouldn’t mind giving the bearing mod a crack. Keep the videos coming👍
Thanks James! I thought for sure no one would be interested! so glad the info came in handy. The bearings are 3/16 - 5/16 - 1/8 (ID - OD - width) the bit you saw in the video I made in the workshop! after I get the latest video wrapped up I'll be doing a video on three different DIY at home methods for installing the bearings! so keep an eye out... And thanks for the support Mate!!
Hey Mark! awesome video on how to fix carbs! iw bin looking after a drillbit like the one you used for the bearings. can you tell more about it? maybee were to get one.
Hey Mate, the bit you saw in the video I made in the workshop! after I get the latest video wrapped up I'll be doing a video on three different DIY at home methods for installing the bearings! so keep an eye out... those bearings on the throttle shaft make such a difference!
The spring rarely needs altering in cars, boats that run around at full throttle can benefit greatly tho. Walbro actually sell springs in different rates!
crankshaft vacuum is sucking fuel into the nitro carb, and at the same time exhaust has a pressure line into the tank pushing fuel. Gas engine has none of this, he explained one port from engine to pressurise the carb with pulses that draw the fuel in
133levi 668 carb used up to 26cc engine and has manual choke 990 carb used on bigger engines up to about 30 cc. Maybe 32 cc. Has no choke I’m fairly certain this is correct but someone might be able to confirm
I like the details of the carb workings. BUT, for a $12 carb (new) vs $5 for a carb kit, isn't it better or more cost effective to go with a new carb? My 5 year old (on a shelf for 5 years!) Redcat xt, that I've had 3 weeks, the carb was junk from the factory. I replaced it with a new $12 (USA) carb from Amazon, & it runs like a new, broke in 100cc engine now. LOL! It had some carb issues, factory.
because your new $12 carb is a fake clone carb by RuiXing etc and not a geuine Walbro carb. Mark doesnt buy $5 carb kits either. He buys genuine Walbro. Everyone has a different budget, nothing wrong with that. Also judging by the views there is appetite to learn and service items even in a disposable society. Hows the Redcat?
Hi Mark, great video on rebuilding the carbs. Already purchased some rebuild kits for my WT-990 carbs, but finding it hard to find a supplier for the the shaft and butterfly in Oz, where did you get your from?
Good to hear you're having a crack at rebuilding them mate!! Hobbies Direct have them in stock and express post for those like me who hate waiting for parts! hobbiesdirect.com.au/Zenoah-Walbro-Carburetor-Throttle-Shaft-Kit-T207081370?search=walbro%20carby let me know how you go...
Hi mark i have a hpi savage octane, with a walbro carb and when i accelerate the engine get bogged and dies ive messed with the high and low speed needles but i havent had any luck any ideas?
@Isaac Estrada start with the simple things first... 1. check the fuel delivery, the clunk in the tank might be blocked - disconnect the fuel line on the carby and blow back down the line (just use your breath) the filter / clunk might be blocked. 2. pull the mixture screws out and check the ends for damage 3. reset the mixture screws to default 4. check the vent hole on the metering side (I detail it in the video, fuel metering side) 5. haha if that hasn't fixed the problem, you better order a rebuild kit! If you have any more questions DM me on instagram - 76thomassonm
@@MarkThomasson76 thank you for the reply, I actually concluded that it was the engine I ordered a new piston ring and sleeve hopefully that'll do the trick thank you
It’s a pretty amazing little one way valve setup! Haha I don’t even really understand how they work?? Walbro should make them removable. Actually have you seen the new Mecatech carb?? Wonder what their doing for a one way? Check it out, looks AMAZING $500aud tho!!!!!!!!!!!!!!!!!!!!!!
in my opinion one of the best, accurate, detailed, diy carby rebuilt and explanation video, by a long shot. well done!
i keep coming back to this video just so i don't forget anything on my carb rebuilds.
Mark this has been the best Walbro carb rebuild I have seen, it really helped my own rebuild. Great job.
Though I’m an rc airplane guy, I enjoyed your excellent video. The non-serviceable inlet is the “seat check valve”. The other side has fingers crimped in holding a little disk. They do go bad, and it’s fairly easy to destroy one with a blast of air or carb spray. They are “non serviceable” in the sense that Walbro has discontinued those parts, but you might find old stock on line. Old one can be removed with the right size screw or the Walbro tool kit once contained a punch. Some models also had pressed in ‘nozzle check valve’ which had the crimped end in the throat of the carb as part of the main jet.
If damaged, at idle there is vacuum on the idle port because it’s inboard of the throttle plate, but there is not enough flow through the Venturi to create vacuum at the main jet- so the idle jet might pull some air in through the main jet instead of drawing fuel from the metering chamber… erratic/unstable mixture at idle.
Anyhoo, can’t really blame Walbro for discontinuing those parts. I think most of their business is from power equipment repair shops, and no one is going to want to spend $22 for rebuild kit, like $80/hour shop rate- and maybe end up with a bad and not available check valve. People either get a new (or knockoff) carb, or in the case of a cheap string trimmer- throw the whole machine away
Amazing - just about to service the Walbro WT on my Stihl 024 - owned form new in 1996. Many thanks
Nice job Mark. thank you! This step by step video was essential for a WalBro Carb rebuild on a 25 year old VARIO ALOUETTE II 1:6 scale RC helicopter. I’m now Celebrating with a smooth idling engine after …… well…… 10 pulls. What a difference! Idling like never before. Side note: As I didn’t have profi punch tools needed for refitting the Welsh washers (?), I used similar sized hex drivers….. with success! I did struggle with the smaller copper fitting … mine did not come out as easily as yours. Beware. Flying this coming weekend. Regards from Switzerland
Loved the info you gave us in this video. Taking the time to explain everything pertaining to the functionality, which is very important to having a running work on carb in the end. Finally I got to see behind those welsh plugs. Thank You.
Please do the bearing video! Dimensions for the tool as well. Thanks Mark
Hey Mark. Nothing but boring is the video. It is awesome. Great pro work again my friend. It is by far the best video for carbs. You are the leader. Keep going man.
Thanks George! I thought for sure it would have been too boring for everyone! Mate its winter here now, wish I could be over there racing in the sun with you boys!!
Not long winded at all. This was a great video. Thank you for your time.
20:55 just in case everyone wasn’t paying attention this is the critical moment in the video where we learn how to address a lean/rich carb AND CORRECT IT without the official Walbro W tool
great job Mr Mark and thanks
Awesome. Good video. Pls let me know which bearings I need for wt603b. I will start rebuilding 10 carbs which bit I need to bore out carb bearing hokes
Great video. Thank you. Perfect amount of detail!
Thanks Mark. Keen on the bearing video as well.
Good work. You explained the workings of the carby really well.
Excellent video. Great advise for things to check when your carburetor performance goes south.
Thanks Legend!! really appreciate the support!
Mark thank you so much !! The best explained carb function ever :) I am repairing my old chainsaw and I now finally understand how these small carbs work! Cheers , Z.
Can you make some more videos please? These are great, best on TH-cam. We need more.
Fantastic video. Thanks so much Mark.
You are a legend for these videos, do you happen to have a video on how to bearing mod a carb?
very good video I'm looking now to understand better to make a perfect adjustment of the carburetor and explain the features of the high and low of the needles how to adjust for start and end of acceleration thank you very much
Great video!! Any update on the carb bearing mod video? Looking to do the bearing when I rebuild my carb
Hola. Saludos desde chile. An pasado años desde que hiciste este video. Pero te agradesco igual. Me estás ayudando a entender este nuevo mundo RC 1/5. Saludos y muchas gracias
Id like to see the bearing mod done.. Step by step... Bearing sizes and tooling used... Thanks for the vids, I've learnt heaps..
Comprehensive explanation dude
Thank you
Thank you Sir. Awesome work video on explanation of carb work! 👍👍👍
Hello great video you bought either the bit or the cutter for the bearings in the carburetor thank you
Just found this, awesome, any word on when the bearing mod video will be up. I have a small lathe and mill so I think I can certainly start doing that on a carb I am about to rebuild
Extremely good explained! I feel like an expert now😀👊
Thanks for the video,very helpful. But i have a question. What drill did you have for drilling out the bearings. Partnumber of link would be very nice. Best regards
Great video
Question my car seems to be shooting a lot of gas out the carburetor and it won't stay running any suggestions?
You are a legend mate love your videos and yes I really want to see your bearing videos I have some old carbs that have so much slop👍
Hahaha thanks for the support legend!! really appropriate the questions and feedback!
Did ever do a bearing video for the carbs.
Thanks Mark for this nice explained video about the carburator overhaul action! Will share the link ;)
Thanks Mate!! really appropriate the support (and great videos too! your track looks mint 👌)
Great video!thank you!
Hope you can help me.
If i pump my primer bulb air goes out but no fuel comes inside .
I already changed all gaskets and diaphrams and screen with walbro rebuild kit and used air compressor in every hole.
Should i try to remove the welch plug??
Thank you
What size rotabroach were u using mark
Solid explanation of carb workings etc
Have u thought about doing the metering mod where essentially u take about 3 coils from each side of the metering spring to bring the pop of pressure down to 16psi
Regards
Very good video best yet!
Hi, great video, good work,
Great job bro!
Thank you for all the info. Awesome to a newbie
Great channel! Hope it grows!
Mate this is an awesome video. Great work
Thanks so much for the support, really appreciate it!
Hello. could you give my walbro wt668 a review ?? I really like the improvement of the bearing on the throttle shaft, just with that, my carburetor would last a lifetime, hehe.
Mark great video! I need help with someting you did not cover though.I got a used old weed trimmer with a carb. almost exactly like yours, however under the primer there no orange ring like yours. Is that something that should there? I can't get it to prime?
What size bearings and what size cutting tool did you use for the bearing mod?
Brilliant video, would love to see one on a 990 and the bearing mod too! The small welch plug in your carb doesn't seem to be present in mine, I whacked it a few times and it's solid.
Have you stopped doing videos ? not seen any new ones lately . would like to see carb bearing mod
You filled a great niche, your instructional videos on RC motors (I'm into GoPeds) exists nowhere on this platform other than on Derek Short's channel. Although he will always be leagend your vids are so much more clear and we'll edited.
I can't find the repair kit for the walbro 998. Where can I find it? I live in Brazil
Great video, thanks! I have same car, CY 24cc when I got it, it started up immediately. Then it was sitting on the shelf for few weeks before going to the track. There it just did not want to pump fuel and barely get it going. Now I rebuild the carburettor, pressure tested it and it is ok. But the motor still wont run. L needle is 1,25-1,5 turns. I managed to get it going for few seconds if I remove fuel intake line. Motor has spark, carb does not have a choke. Can you give an idea what to do?
On the carb which is the inlet and which is the outlet?
I am rebuilding a Zenoah 230RC1 for my Gasser Helicopter, and i knew nothing about these engines, but your great videos are helping in the extreme, keep it up, and can you do on on tuning? P.S. i love the music you chose!
Gday Mark best video on TH-cam explaining the carby... and believe me I have watched thousands.
Would you have a part number for the milling bit you used and are they 5x9x4 bearings wouldn’t mind giving the bearing mod a crack.
Keep the videos coming👍
Thanks James! I thought for sure no one would be interested! so glad the info came in handy. The bearings are 3/16 - 5/16 - 1/8 (ID - OD - width) the bit you saw in the video I made in the workshop! after I get the latest video wrapped up I'll be doing a video on three different DIY at home methods for installing the bearings! so keep an eye out... And thanks for the support Mate!!
Mark Thomasson Thanks will do.
hi, any chance of the bearing size and drill used great video 👌
the bearings from 3/16 x 5/16 x 1/8 to drill is 5/16.... thanks
What does it mean if you try to lean the low side of the carby and it doesn’t raise the idle??? Ever time I try to do it it does the opposite
Thanks bro rovan was nat starting tune, but nat as u explain 🤔
Hey mark where do you get the bearings from for the walbro carburetor
Hey Mark! awesome video on how to fix carbs! iw bin looking after a drillbit like the one you used for the bearings. can you tell more about it? maybee were to get one.
Hey Mate, the bit you saw in the video I made in the workshop! after I get the latest video wrapped up I'll be doing a video on three different DIY at home methods for installing the bearings! so keep an eye out... those bearings on the throttle shaft make such a difference!
yes please on doing a bearing video .
very nice video can you tell watt drill do you use to make the hole for the bearing?
miguel ferreira it’s called a reamer
Bro you got one of them peaky Blinders haircuts cool lol
Loved the video. Had to share it :).
@EV TEK thanks legend!! and thanks for the share! are you running anything on-road?
So how do you do the pop of spring mod on your carbs
The spring rarely needs altering in cars, boats that run around at full throttle can benefit greatly tho. Walbro actually sell springs in different rates!
Great video bud👍👊🏻💥💪
Thanks Legend, really appreciate the inspiration 👊👌
NICE 1 SIMPLE SIMPLICITY 💚💛❤️🤜🤛
What drill bit do you use ? mm size
What a Thing. Why the gasoline carb has to be so much more complikated than a Nitro carb?
crankshaft vacuum is sucking fuel into the nitro carb, and at the same time exhaust has a pressure line into the tank pushing fuel. Gas engine has none of this, he explained one port from engine to pressurise the carb with pulses that draw the fuel in
Hey i did all the steps but mu primer bulb is not holding in the gas
Can you explain the differences in the 603-668-990
133levi
668 carb used up to 26cc engine and has manual choke
990 carb used on bigger engines up to about 30 cc. Maybe 32 cc. Has no choke
I’m fairly certain this is correct but someone might be able to confirm
Very clear, thank you
do put a bearing both side
I like the details of the carb workings. BUT, for a $12 carb (new) vs $5 for a carb kit, isn't it better or more cost effective to go with a new carb? My 5 year old (on a shelf for 5 years!) Redcat xt, that I've had 3 weeks, the carb was junk from the factory. I replaced it with a new $12 (USA) carb from Amazon, & it runs like a new, broke in 100cc engine now. LOL! It had some carb issues, factory.
because your new $12 carb is a fake clone carb by RuiXing etc and not a geuine Walbro carb. Mark doesnt buy $5 carb kits either. He buys genuine Walbro. Everyone has a different budget, nothing wrong with that. Also judging by the views there is appetite to learn and service items even in a disposable society. Hows the Redcat?
Carburettor quality wall bro quality Elisa.sir..RS
Hi Mark, great video on rebuilding the carbs. Already purchased some rebuild kits for my WT-990 carbs, but finding it hard to find a supplier for the the shaft and butterfly in Oz, where did you get your from?
Good to hear you're having a crack at rebuilding them mate!! Hobbies Direct have them in stock and express post for those like me who hate waiting for parts!
hobbiesdirect.com.au/Zenoah-Walbro-Carburetor-Throttle-Shaft-Kit-T207081370?search=walbro%20carby
let me know how you go...
Mark Thomasson
Hi Mark, thanks for the info on the shaft supplier. Will keep you updated.
Were did you buy that drill bit from and what’s the bearing size you used
@George Specs - I'll detail and show 3 different methods in an upcoming video! it'll cover a couple of different options!
Hi mark i have a hpi savage octane, with a walbro carb and when i accelerate the engine get bogged and dies ive messed with the high and low speed needles but i havent had any luck any ideas?
@Isaac Estrada start with the simple things first... 1. check the fuel delivery, the clunk in the tank might be blocked - disconnect the fuel line on the carby and blow back down the line (just use your breath) the filter / clunk might be blocked.
2. pull the mixture screws out and check the ends for damage
3. reset the mixture screws to default
4. check the vent hole on the metering side (I detail it in the video, fuel metering side)
5. haha if that hasn't fixed the problem, you better order a rebuild kit!
If you have any more questions DM me on instagram - 76thomassonm
@@MarkThomasson76 thank you for the reply, I actually concluded that it was the engine I ordered a new piston ring and sleeve hopefully that'll do the trick thank you
Nice one Mark.
Only 30 more subscribers till you get 200!
So amazing isn't it!!! it wouldn't happen without the love and support of people like you RC Girl!
I find it’s that non serviceable check valve that renders most of my carbs scrap
It’s a pretty amazing little one way valve setup! Haha I don’t even really understand how they work?? Walbro should make them removable. Actually have you seen the new Mecatech carb?? Wonder what their doing for a one way? Check it out, looks AMAZING $500aud tho!!!!!!!!!!!!!!!!!!!!!!
Awesome thanks
Thanks for the support mate!!
👌
ANY CHANCE YOU CAN HOOK ME UP WITH 1 OF THEM DRILL BITS PLZ 😁🤜🤛
Please
who doin that crap, new carb is 25€
You should have listed a link for the bearing , sometimes it's not easy to find the bearing
What size bearing did you use ?