XJ650 jetting / mods for pod filter and 4-1

Folks,
Read loads of posts on the issues running these bikes with pod filters and a 4-1 exhaust. However, that’s what I have so I’m looking for some info from anybody that is currently running pods. What size fuel and air jets are you running, both main and pilot. Somebody must have a set up that allows ‘acceptable’ power delivery / smooth running with pods so appreciate if you can share jet sizes to give me a good starting point. Also have you done any other mods to carbs? I’ve heard of drilling the bottom of the slides but bit wary as obviously this can’t be undone!

TIA
Mark

 

Hi mate,
I have pods, 4-2 exhaust and a lot of engine mods. Check out my videos as they might help you. As a start I’d suggest going only plus 2 to 4 on your main and maybe plus 2 on the pilot.I drilled out the slides and am happy with that mod, I didn’t do any other mods besides changing jets. It’s going to be trial and error and will take time to get right. In the end I have mine running well.
Hope this helps.

 

thanks Mezzmo, seen your videos, great help.

 

Mezzmo,
A quick question about the V seals on the throttle shafts please. I just want to be 100% certain which way the V seals are inserted it's not entirely clear to me on the video footage or when you say facing/pointing out. Do you mean A or B on my attached sketch. Sorry if it is a dumb question but I have a problem with my carbs and I'm wondering if I misunderstood your video instructions. Thanks very much

 

mark, I found your attachment confusing cause the throttle shaft seals are a V or U shape vs a normal O ring. He can answer this but its pretty clear to me @ 5:46 you can see that the open end of the U/V faces out.
inside of the carb is a vacuum of pressure compared to the outside of the carb, so the outside wall/flaps will flex and seal the contact.

This is why they don't use an O ring (and nor should you from any of the cheap carb kits out there) cause the O ring needs pressure to seal which puts friction on the shaft from rotating and can cause other problems not to mention that the shaft is not designed to put pressure.
See the screen grab of his video that shows the outside view of the seal. Obviously, when you insert the TSSeal onto the shaft for the other end, you are again making sure the proper end is facing out. His Carb video is VERY good. It does not cover a few minor things that if you read enough here, you will get though (like verifying the fuel enrichment path on the main carb body is clear, There is a link to that on the carb page on xj4ever. (He does cover the bowl passage though)
Cudos again to Mezzmo

 

Melnic,
Yes, wasn't the best drawing(!), I maybe should have explained it a little better. The triangles on my drawing are meant to represent a sectional cut through the V ring. Top drawing (A) shows the point of the V ring towards the throttle valve (pointing inwards) and the bottom drawing (B) with the point of the V ring towards the outside of the carbs. What you are saying is that the open end of the V faces out, i.e. my sketch A, and I agree they do look that way in the video if you freeze frame it. This is the way I installed them, and as you say based on the vacuum this is the way that makes sense, but due to having some ongoing problems with my carbs I just wanted to double check and be 100% certain.

I agree Mezzmo's video is great. In fact I was having real difficulty identifying the proper throttle shaft seals, let alone buying any in the UK and I paused Mezzmo's video on the packet of seals so I could get the details and get them ordered!! So yes, Kudos to Mezzmo and thanks to you for answering my question.

Thanks

 

So were you able to locate some in the UK?

 

Hi mate, I can’t open your pic but take another look at my video as I do show the seals faces with the v on the outside.
Remember your carb is mostly under vacuum so the seal faces out so that when vacuum increases it allows the seal to expand to create a good seal.
You will suck in air if the seals aren’t put in the right way. Hope that makes sense…

 

No, had to order from EU as per name on packet in the video

 

Mezzmo, you say ‘v on the outside’ and ‘seal faces out’. Does this mean open part of v seal to the outside and pointed end towards the inside of the carb? I’m fairly sure I can see it this way from your video, and this way makes sense regarding vacuum, but wanted confirmation. This is also the direction Melnic explains above. Thanks

 

Yes, the v side of the seal is on the outside of the carby and the other side is square faced and goes on the inside edge.

 

I purchased my seals on eBay, they are from Germany… https://www.ebay.com.au/itm/3842918...vklWyN-RaW&var=&widget_ver=artemis&media=COPY

 

Perfect, thank you. The penny has just dropped for me!
I now understand when you say the ‘v on the outside’ when you mention the true shape of the seal (square on one end and with a v in the other). Total misunderstanding by me, feel stupid now especially because I’m a time served engineer and I’ve had the seals in my hand. Doh!

Thanks again, and I’m happy I’ve definitely got the seals in the right way.

 

All good, no such thing as a silly question....