Mikuni BDST 38 Full restoration - Part 2

[@todortodorov8508]

Great presentation and description of the details, you have amazing skills thanks for you and greetings from Bulgaria.

[@ChrisSofos]

@todortodorov8508 Thank you very much for your encouraging comment!! When I visit Greece every summer, I stay in my hometown, which is very close to Bulgaria. Maybe we'l l meet next summer 👍

[@itsanarse]

Thank you for this, gave me the overview I needed for my Ducati

[@ChrisSofos]

You're welcome 👍

[@bjornnijhof2489]

Thanks for your effort, exactly the right video I needed. Keep up the good work, it's really appreciated!

[@ChrisSofos]

Thanks for your kind words! Ride safe!

[@peteryule6192]

Thanks, you helped me out. Appreciate your work.

[@ChrisSofos]

You are welcome and thank you for your comment! I'm glad I could be of help!

[@t.v.n5266]

Хорошее видео, отличная работа👍, посмотрел все части. Очень помогли с ремонтом. Спасибо.

[@ChrisSofos]

You are very welcome! Thank you for your comment!

[@haazen1987]

My yamaha 750r 1995 has a leaking problem, thanks for this videos,

[@ChrisSofos]

Thank you for your comment! I appreciate it!

[@muller_]

Thanks just what i needed. Near the end off my building process all thats needed now is to rebuild the carbs and then some small adjustments... hope the blaster will still be practical as im sticking with the fzr's front sprocket and the blaster's rear sprocket tooth count😂 Thanks for the informative video sir!❤

[@ChrisSofos]

Thank you for your comment! It always pleases me to hear I became of some help to others!!! Let me know how you go with your FZR 👍

[@andrewtipper2792]

Great video Chris. I'm getting my 1990 exup back on the road on the road so this has helped. However i have a problem i cant fix. The revs hang after blipping the throttle and slowly settle back to idle. I think everything is ok. Ive had the carbs ultrasonically cleaned but still have the problem. I cant find any air leaks and mixture screws are 2 and a half turns out. All seals and gaskets are relatively new. Anything i should check? Andy

[@ChrisSofos]

@andrewtipper2792 Thank you for your kind words! As for the problem you're facing: I'll take your word that carbs seal to inlets perfect and the seals are not cracked. Also, I assume that the inlet manifolds (the aluminium ones) are sealed properly to the cylinder head, and their o-rings are in great condition? These inlet manifolds usually warp a bit and can't seal properly. If that's the case, remove them, place them on top of a 400 grit sandpaper wetted with WD40 on a flat surface, and grind them down. If all that is ok, and still after blipping the throttle, the revs go higher, this means there's extra fuel going into the cylinders. More than the idle system allows. In that case, make sure that the throttle FULLY returns back and doesn't stack at all? Last but not least, the 2.5 turns out might not be suitable for your engine. Once you adjust them the way I showed in this video, you'll be surprised how the engine is going to run and how different the pilot screws will be set. I hope I can help. Let me know how you go

[@andrewtipper2792]

Hi Chris. Thanks for the advice. I'll check the manifolds this week. Must admit its something i hadn't done. I will also go through the pilot screw procedure carefully. I'll let you know!

[@sekaf4125]

very good video! I have a 2001 Yamaha FZ! it has Mikuni BSR37 carbs I believe. Also has Ivans jet kit. My bike sat 12 years because of surgeries. I have it running now. There is a little burbles at low rpms. Im going to clean them. I ordered new boots and carb gasket kit. Im very nervous don't want to screw things up. You have any tips or video on those carbs? Very well done video. GREAT photography. Up close, well lit!

[@ChrisSofos]

Thanks for your encouraging comment! However, I've never come across your type of carbs, so I have no video or idea of their details. They all work the same, more or less.

[@sekaf4125]

Thank you

[@mmotorcycles9497]

I have a yzf coming my way that’s having carb problems. I should have them sent to you.

[@ChrisSofos]

I'll take that as a compliment! Thanks man! I might have to sent you the Gixxer's fairing as well.

[@mmotorcycles9497]

Starting a 91 gsxr this week

[@ChrisSofos]

@@mmotorcycles9497 I'll be watching!!!!!!

[@ciogon]

Chris,i need your advice on my fzr 1000,its a 3GM from 93...ive rebuilded the engine..i have 13,4 bars compression on each cylinder,carbs rebuilded too..everything is stock...but i cant adjust the pilot screw as you say..starting from 2,5 turns out as per manual,closing it until engine rpm drops,then opening it up until engine rpm drops again...but it doesnt!it only drops on closing,but when opening the screw slowly,the rpm doesnt drop...so i cant do that adjustment...can you give me some advice please?the float height is 14 mm from the matting surface of the float bowl...the needles are on the second groove from the bottom..so 4 groove from the top..engine runs good,no black smoke when giving throttle...idles good,pulling the choke while running hot,makes it die...so its not a lean problem...

[@ChrisSofos]

@ciogon before you do the pilot adjustment, try to do the throttle adjustment (synchronising them). Then try the pilot screws adjustment like I'm describing it, but remember: don't expect the revs to drop much. Actually the drop it's going to be minimal. So minimal, that you can barely hear the engine's rpm drop. Another thing to keep in mind is that you have to screw-unscrew the pilot screw veeeeeeeeery slowly. If the rpms still don't drop when unscrew, then there must be some issue on the pilot system. Usually, it's the o-ring of the pilot screw. It's cut or squashed, or there's no washer in there. Any of that, can affect severely. Once you do all that, do a final throttle adjustment once more, and you're done. Let me know how you go

[@Jumbojt]

Hello Chris. My Fzr 1000 dont work properly, problems with 4th cylinder. Its the carbs and I had a problem few weeks ago with fuel supply, didnt get enough fuel because of bad fuel filter. I started it today and noticed a huge leak between 3rd and 4th carb, its o-rings I guess. Could that be the problem for 4th cyl not running before the leak? I think maybe it was not leaking fuel but got air leak there so cyl 4 didnt suck enough fuel? (there was slighty missfire from exhaust) And I noticed my fuel pump works only few seconds when I turn the ignition on, when it starts its not working anymore. So I connected fuel pump with separate switch to work all the time. Is it suppose to work all the time?

[@ChrisSofos]

The fuel pump works like that. It starts for a few seconds, and when the pressure builds up, it then stops through the fuel pump relay. As for the 4th cylinder, the leak might not be the issue ! First, make sure the spark plug on this cylinder ignites very well. A good trick to check this, is to swap the spark plug cables on cylinders 1 and 4. If the problem is now on cylinder 1, then the ignition is your problem (bad plug, bad coil, bad high tension lead). After making sure the spark plug or the cable or the ignition coil is not the issue, then go to the carburettor. The issue might be the low fuel level. If it's too low, no fuel will enter the cylinder. You'll need to adjust the fuel level if that's the case. Air leaks are another major factor. Lose rubber connector, or a broken one, is usually the case.

[@kalobesh]

Thank you so much from me as well for the video, I am saving it in a playlist. I have a Yamaha XTZ750 Super Tenere and I think that it has the same carburetors :) . After I rebuild them I try to synchronize them by ear and eye. Only once I managed to make it start perfectly, but it was running too rich and didn't run well when accelerating. Also, at 14:59, there is a tube(I think it goes to the air filter box). I also have such a tube on mine, but where does the other end go? Again, thank you and ride safe :) .

[@ChrisSofos]

Thank you for your kind comment! It feels great to know my video can be of help to someone! Your Tenere has exactly the same carburetors. However yours I think it has an accelerator pump on the bottom of the float bowl (I'm not sure). This doesn't change anything though. The tube you are talking about is an air ventilator. In my FZR goes from the carburetors to the top of the engine. There are some steel pipes that hold that other end. In a few words, it goes to the atmosphere. The factory settings on the pilot screw for yours, is 2 turns out, so start from there and see how you go. All the best!

[@kalobesh]

@@ChrisSofos Thank you SO much, I managed to get it working very well when warm. Thanks to your video I ordered the same sync tool, I hope that it arrives before it gets too cold outside(I live in Bulgaria, the weather is not very stable) :) . I think that it has that pump, if I understand correctly - it's a membrane with a spring. Thank you again for helping me and others so much, I wish you all the best, I really do. You are an amazing person! Sorry for my late comment, KZbin didn't notify me about your reply.

[@ChrisSofos]

@kalobesh no problem, buddy. I tend to get late notifications from KZbin, too. I'm happy to hear it went well. I'm familiar with your weather. The place I'm coming from Greece is really close to Bulgaria

[@valentincosmin4391]

hello, great video, an i ask where did you buy the vaccum tool from? cheers

[@ChrisSofos]

Thanks for your comment! I bought it from eBay. I have a link on this video's description, but here it is again: www.ebay.com.au/itm/271706450468

[@TheMultik67]

Спасибо за видео.Очень интересно было посмотреть.Привет из России

[@ChrisSofos]

You are very welcome! Thank you for your kind comment!

[@ademcerkez4606]

I have yzf 750 r Is it possible to have correct idle without airbox and filter and when you adjusting the pilot screw is it with or without air filter

[@ChrisSofos]

Very good question! Yes, that is correct. The idle will be correct without air filter/box. When the engine is idling, there's no difference whether the carburetors are naked or dressed with the air filter/box. There's no load on the engine, so no problem. This is why you can do the adjustments without the air filter/box. Just like I did.

[@ademcerkez4606]

Ok thanks for answer