Grim

The high idle follower was flapping in the breeze, and the right throttle stop was way out (someone had been here before and was only using the left for idle) it initially read 84mv. When I got 157mv the butterfly was sticking in the bore. I feel I definitely got that bit right.

Thanks for believing in me (or at least my left cylinder) Positive steps.. I'm going to check compression tomorrow. I'm going to try resetting the throttle plates and get them aligned somehow....

Interesting, I know the bs34s are hard to get right. That's why I went with modern CVKs from a Kawasaki Ninja, modern carbs feel leaps and bounds ahead of the originals.

Thanks for you continued interest. 1. I will tomorrow, couldn't get a compression tester until then. 2. Left is, have another in the post from (kindly donated by Stewgnu) so soon the right will be. 3. I could, won't it just not run at all on that cylinder? 4. Right now, I don't *think* so. I am feeling like if the right is pulling more air and the screw is closed, then it would make sense that the butterfly was open more that the left at idle? I want to be in a position to open both air screws the same amount, therefore the right butterfly needs to close. I think...

Ok... some things to note. Both sparks are good and strong But the left is definately rich at idle, sooty plug Right plug is good. I removed Meinhof's latest map, and wrote the standard map to the ECU. Surprisingly it started running a little better..... To get it to sync up last time I had ended up with the right air screw all the way in, the left about 3 1/2 turns out, which is not great. I wound the left air screw all the way in, the revs dropped but so did the stumbling, I got a steady beat from the left hand pipe, but then the throttle body sync was miles off. So the RIGHT cylinder is getting too much air, the air screw is all the way in but the vacuum is much lower than the left. The following video shows (aside from a fool who is very bad at filming /motocycle diagnosis) the following point: Standard map back on, both air screws fully closed. Sync is off, right hand has less vacuum. Winding the air screw out (alot) and can bring the TBs into sync. This seems wrong, and the issue is the right hand side having too little vacuum? Please excuse the home made mufflers, the nighbours were going to get pissed off at me if it went on much longer so I had to do something! I guess the throttle butterflys are not aligned, or I have an air leak in the right. I found aligning the butterflys difficult, the ball joint seems to want to go on all too easily, like it's not precise enough to ensure the plates are aligned. I tried gstallons method of aligning the other end after removing the eclip, bit don't dare much better.

It's going to end up like a Giallo soon in the garage.... Yes, I have to invent my own problems with the XS... Like wouldn't it be somehow be better with Kawasaki Ninja carbs, or Honda CBR coils?

Yeah, brand new plugs. There's a small indy garage down the road, I could ask there.

Will do, it's starting to drive me mad.

I did use the method you described, with the rod connected the feeler gauge set just slides out of the throttle screw/plate on the right hand side. One thing that was tricky here, the white nylon knob is very tight, and doesn't really allow any adjustment ( it tries to spin the ball joint on the right). I took off the e-clip on the left and then got the thing to line up that way, then wound it a little more so when the rod was connected the feeler gauge fell out on the right. At that point (the tps was reading 550mv) connecting the vacuum gauges up gave pretty much the same reading as before, so I opened up the air screw (both were fully closed) 'till they were balanced. Still got that weak left hand pot, maybe it is compression, I'll get a tester tomorrow.

I have yet to test compression, I will try to get that done. The spark plugs read 8300 Ohms on the right, and 7900 Ohms on the left, is this cause for concern (this is with brand new plugs). I set the throttle stops as per the feeler gauge method and then connected the rod, the balance was off, but could be brought level by using the air screws. This did not work when winding them out the same amount, but through doing each side individually I could get the vacuum level to sync up. All the way through this the right hand cylinder is just chuffing away beautifully, never faltering, and the left is stumbling away. I did a little video: https://www.youtube.com/watch?v=ZeR9KYqC2pA

Can you elaborate please? So you put a feeler gauge behind the r.h. idle screw and then adjust the white knowb till it contacts? I am trying to get a feel for lots of different peoples approaches, hoping that one sticks...

just realised a typo, it's highboy_coupe@yahoo.co.uk

I've got the intake rubber off (fun), and it doesn't seem to have any rips that go all the way through, they're pretty thick really. The inside of the tb is very dirty behind the butterfly, very grimy, I'll give it a scrub. I'll stick the new one on when it comes and see, but I don't hold out much hope for it fixing it. If I'm still stuck after that, can you measure the primary resistance at the ignition lead? Or is it tank off and test the coil off the bike? Thanks

Phew, well thank you for that. Out of interest is there a value given anywhere for vacuum? I'm going to sync after I put fresh rubbers on, my attempt with the silicone has done nothing to help matters.

Ok, scored a set of vacuum gauges, which has led to some confusion on my part. Yes, the TBs are out of sync but the good (right) cylinder is hovering around the 200 mark in the red (intake leak warning red). The stumbling left cylinder is at 100. Now that is about the same vacuum I can muster by sucking on the tube myself... what actual vacuum reading should I be seeing, just so I know (even if that is not important at this point!)

Ah, that would be brilliant Stew, I spent last night coating my old ones with silicone in attempt to seal up any hidden leaks... Do you want to invoice me with PayPal? (highboy_coupe@yahoo.co). Re: the neighbours, Yeah, I have young kids and I'm aware of other young families and how loud a stationary Mistral equipped V11 can be.

If I get a manometer, can I just sync at idle or do I HAVE to do it at 3k? My neighbours are going to love me ...

Thanks, the CO trim was zero in Guzzidiag when I checked, one thing I'm not clear on, does this change with engine temp? People say to zero it AT 60 degrees, my zero setting was seen with the bike cold. I have not altered the sync of the tbs yet, I don't have a nanometer. My Tb to head rubbers are definitely old and crusty, but I don't see any rips. I have a Mistral crossover, there is definitely some chuffing on both sides at the downpipe join, but as the right hand cylinder runs beautifully I wasn't to worried, I do have exhaust gasket sealant if you think it will help?

Thanks, Charging was around 13.8v last time I checked, the battery was allowed to run down during the current lockdown, the bike has not been in use for a few months. I charged the battery back up and it started the bike ok. But I have not checked charging since. I will do that.

Hi, I realise that misfires are very common forum fodder, I have read as much as I can before posting, I apologise in advance.. It's a 2003 sport, still with external pump and filter. What I thought was a random misfire at idle when hot is actually a persistent misfire on the left cylinder. Originally the valves were tight, I have tried the valves at .004 and .006, now set to .006 and .008 with no real difference. I tried new plugs (gapped) and I have checked the leads for corrosion. I have just done a TPS reset. It was at 85mv fully closed, it is now at 157mv. Air bypass screws are 1 turn out Idle is at 1300rpm On idle if I go to the back of the bike, the right hand exhaust gives a consistent rythmic slap if you put your hand gently over the can. The left hand side is weaker and faltering, kind of "off beat". At the tachometer needle kind of wobbles a bit at idle, if you rev it to 3k you can hear misses and the tacho jumps around a bit more. There are no backfires at all. Can I test the coils on the bike without taking the tank off again? I know these threads never get resolved, and I appreciate that misfire diagnosis through a forum is not the most realistic expectation, I am just at my wit's end, and I have probably missed something. Thanks

sorry, Imgur was not playing ball. fixed

Installed my genuine err... Vespa.. shift lever pivot bolt and brass bushes today to take out the horrendous slop (the pivot was bent!), nice and tight now. Seems they don't even bother to mention Guzzi on the factory parts any more, too exclusive??😁 Getting those original bushes out was interesting... I see the new ones are slotted, to allow easy destruction later.

Got myself a replacement steering damper Heim joint with it's own little grease point, how sweet! Does anyone have any tips on setting it so it doesn't reach the end of travel before full lock, or hit the clamp? Trial and error?

I also recently installed the latest version and zeroed my fuel trim, it make a massive difference doesnt it?! I used 004 and 006, which I believe are universally accepted...(I might be wrong).

Didn't take a photo of the pile of dirt (I would estimate a 1/4 pound) I scraped out of the fins of the engine, particularly the timing cover. It looks like a previous owner painted OVER the dirt.