Hello TK29,

First of all, welcome to the forum.
Do you also have a name?

Regarding your problem:
Too much fuel is also bad for performance, ...what do your spark plugs look like after the test drive (black, wet)??
Is the ignition timing correct?? (... check with the ignition gun on the left side of the engine / sight glass)
Or maybe your secondary-air-mixture-control-valve (sniffer) is stuck (... try disconnecting it or spraying it with starter spray).
Greetings Brunò  

Hi Brunò,

Thanks very much, my name is Teddy Ive added that in now, completely slipped my mind while writing the post!

Yes I thought the same, that you would get pretty similar symptoms whether it be running too rich or too lean so was looking for either while doing all the checks. I did check these after the attempted run but don't recall seeing anything out of the ordinary, they weren't drenched in fuel or soot.

I didn't check the timing simply because the bike was running well before all the work and I haven't done anything to alter it but it is worth checking just to eliminate it, as it is possible when I replaced timing chain tensioner gaskets that timing could have slipped, I have ordered a timing light and will get back to you.

I am not sure where/if I have this on my carbs, I know them pretty intimately now having taken them apart so many times! the carbs have been modified to a full flow system and re-jetted accordingly and they have been running like this since 2019 with no issues.

Cheers

Hello Teddy,
it is a good idea th test your bike with a complete original Carb. to check out proper operation of the engine it self.

To check your Camshaft position it is realy easy. Therefore you have to remove the front cover of the left engine cover( not the hole thing, just the Round Cover, 3 Screws, to see the timing inspection window.  Additional the Plug in the center to get access the the crankcase.
Now remove the both Cam-Shaft-Covers on each Cylinder Head. The forward(Cylinder #2) is equiped with the Cankcase brether tube.
After removing the spark plags, you start with the rear Cylinder (#1) .

1. You need suitable tools to turn the Crankcase, turn the crankcase clockwise , see the direction arrow on the Cover.
2. try to seal the rear Spark plug threat wit one finger, turn the Crankcase until you feel increasing pressure at you finger. Then you are in the Compression stroke of Cylinder one.
3. Now, have a look the the Timing inspection window and turn the crankcase a little more until the smal inticator allign with the fly-wheel mark "T". Now, check the markings of Camshaft rear cylinder (#1). You will find two markings. 1st on 12 O`clock position of Cyl-head housing, 2nd o n the Camshaft sproket wheel (a dot). These both marking shall in a line from Cyl-Head-Housing and the Center of the Mounting Screw of Camshaft Sproket Wheel. A little bit to the left or to the right is OK.
4. If it is OK go a head with forward cylinder (#2). To get in the Compression Stroke of cyl 2 seal the spark plug threat as before and turn the Crankcase nearly 285 °, If you feel the pressere rising, have a look the Timing insoction window and turn the crankcase slowly to the marking  " I ". This is the markig for Top ead center of cyl 2. To check the Cam shaft positio go ahead like on cyl 1. Check the alligning of the markings.
5. If both cylnder match the recomended ajustments, it is OK.  

Cgrankcase Markings: Have look at this link: https://www.tr1.de/pages/technics_manual.php?key=XV750se&lng=eng&flg=0&pge=2021
Camshaft Markings:    Have look at this link: https://www.tr1.de/pages/technics_manual.php?key=XV750se&lng=eng&flg=0&pge=3106

If not the is a little work ahead. A TIP: Do not take out the Cam shain tensioner first.
If it is neccassary to adjust the Camshaft Sproket-wheel position, you has to loose the Mounting Screw of it.
To do this, use the tools you had used for turning the Crankcase and a suitable wrench for the Mountig screw. After loosing the mounting screw,do not srew it out.
1) Now , at first check the position of the Cylinder in the Crankcase as before. This is neccessary to be sure that the Basic adjustment is correct.
2) Take out the Cam Chain tensioner
3) turn out the Mounting screw of the Cam-chain-sproket-wheel.
4) Be aware the nothing can falling into the Cam Chain chanel.
5) Addention: there is no much room to operate, so be careful. try to remove the sprokrt wheel from the Cam shaft end.
Be aware, that the small pin between Cam shaft and sproket wheel do not fall off ! It is fixation between both parts.
6) to adjust the sproket wheel position you can turn the spoket wheel a tooth fore or aft whatever is neccessary to get the proper position.
Notice: The chain site in opposite to the tensioner is to hold staight during adjustment.

7) If you have got it, screw in the mounting srew until it come in contact with the Sproket wheel. Then install the tensioner with a new gasket/Joint.
Finally tighten the mounting screw acording the recomended torque value. In the same fashion you had loose it before.
Install all before removed parts. Do not forget the Plug-Screw of the crankcase access.

so far, good luck
Regards
Anja

Hello Teddy,

Anja gave me an idea: Do you still have the mixture control valve (sniffer) installed?
This valve opens at about 4000 rpm and releases additional air into the front carburetor.
The hose line for this has a Y-distributor, ...this has a smaller opening on one side.
This smaller connection MUST point towards the mixture control valve.
See here:
https://www.tr1.de/pages/technics_manual.php?key=XV750se&lng=eng&flg=0&pge=4011
If the Y-distributor is installed incorrectly, the front carburetor receives too little fuel and too much air.
Greetings Bruno