Cynic

86 to 88 European spec, not US. As far as I can tell. Look here, very useful. https://www.cmsnl.com/yamaha-xt350_model16846/

That looks a little short on numbers for me, there is normally a 3 digit model identifier at the beginning. Generally a 3 letter/number combo, a 1978 dt125 is 2A6 as an example.

Very nice, 17's and usd front end on mine, a 98, never tire of 6k.... hot water and a thermometer, engines run at around 90 deg typically. see what the gauge reads at around that figure, the manual will tell you the thermostat temp. Boil the water and put the sender in it connected to the bike. Don't do it 'hot' on the bike using the engine as it may not be, what you think is hot may well be fine, not exactly safe either.. Make sure the connections are nice and clean. That can put the reading up too.

Define fairly hot. Vmaxes supposedly run hot and fells like riding a bar b que coal on a hot day but the bikes in aus and the bikes in the uk have the same cooling system. Have you checked the gauge is not reading high.

At least at 32 quid its easy enough to pay it back if they come calling. Which being government based im sure they can. Otherwise forget it.

Got 2 bike excuses myself so I know what you mean, managed to keep hold of mine although (bikes and kids) I have had my turns as 'full time year round rider' and the 'done 80 miles a year' too, as finances changed. Looks like a 'fun in the twisties type. Welcome to the farm.

Yep, was over 600 quid to do the top end of my tdr after it blew with either oem equivalent or oem parts. Over 40 quid for the (non genuine used Athena) head gasket on a 2 stroke!! Could not stretch to the pistons though. Went with mitaka, genuine are well over 100 quid each plus as much again for the rings. For me I would tear down the fzr engine in the off season, clean it and check it. Good money says a lot of it will be comfortably in spec, 4 stroke bike engines, (especially big ones) usually are because even though you think your riding it hard. Your not, if you had the engine to its limits on normal roads you would be in hospital or prison before long. My neighbour rebuilt his 60000km vmax motor and all he changed was the starter clutch and the timing chains. Even the cams were fine. Obviously rebuilt with all new perishables, but otherwise job done.

Why? FZR1000 motors will do megga miles with just basic maintenance so long as they haven't seen a racetrack. The cost of doing an engine like that would cost a fortune.

If you fill out your profile and put a little about you and your bike in the new members area we wont slip up making those kind of mistakes. Post up more about the bike and what your doing. Esp pictures, everybody loves pictures. I think that bike would share a lot of the parts from a DT50m and the TY50m, parts are rare for those but not as rare as the Jt.

Would fitting a later, or earlier system be feasible. Sounds like this cdi is doing a lot more than a normal unit. The sidestand/ neutral cut out is as a rule a separate unit, it has links to neutral, side stand, clutch and sometimes oil pressure to control if the bike runs/starter operates. The neutral light connection makes me think its all built in. None of that helps I suppose, is switching the system out for a traditional 8 wire unit doable, Lh crank case (ideally complete internally), flywheel, a cdi and some time? Not necessarily a zero cost option but it could be a better deal long term. Maybe buy up a complete motor, you don't need a runner after all just the electrics. You don't say if the bike is as important to you as breathing or a workaday 10 a penny shi@box. Which depends on how fixed it gets I suppose.

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=yamaha+jt2+fork+seals&_sacat=0&LH_TitleDesc=0&msnetwork=o&matchtype=b&adgroupid=1300722460260149&geo_id=&test=AprilTest&MT_ID=&cmpgn=373198552&crlp=_&keyword=yamaha+fork+seals&rlsatarget=kwd-81295272683406%3Aloc-188&abcId=&loc=4076&sitelnk=&mkrid=710-55004-18975-0&msclkid=c26942665cbd102741ef1ca1efc2af65&poi=&mkevt=1&adpos=&_odkw=yamaha+fork+seals&device=c&mkcid=2 D- Must try harder... Took 2 seconds.

TLS front brake should stop as well as a period disk, often better, the problem is heat, the more you use it the hotter it gets, friction reduces with heat and dust, drums really struggle with getting rid of both.. Set up right they are certainly not bad, especially in wet/muddy conditions. Most cannot set them properly though so you end up with one shoe doing all the work.

Start with the easiest check, take the left hand side indicator and swap the connections, (they will be together in the headlight, dark green and a dark brown likely with a common earth) so its plugged into the right hand side. If the indicator is ok the problem should swap sides, then you will have to look deeper.

As I said skill, mate used to have an xbr500, no leccy start. Pretty much the perfect anti theft as he was the only person that could start the bstd.

Lovely big thumper, well done on not losing all of them. there is something about a big thumper, takes some skill to ride properly but I assume you are the wheelie mister.

At the end of the day you are arguing that everything is ok, then saying it isn't. Your engine is running rich, that is down to any number of things. Problem is you say they are all fine and its a mysterious problem. Its not, its a machine. It obey's the laws of physics. That means if it has a bright properly time spark, a clean air filter then there is a problem in your carb. Simple. Fit the factory jets and give it another run, something is wrong, random guesses don't help. We are pretty good most times but we only have the information you give and our combined experience. We are both currently concentrating on the carb at the moment. It is possible for there to be crap in internal air ways, could even be floaty bits in the carb that get sucked into a jet, then drop away. Some Chinese crappy jets can be as much as 30% off on calibration, which is unhelpful at best. We are not trying to wind you up, just trying to help you understand a carb meters air as much as fuel. If the amount of air moving is wrong you will never get the jetting sorted, if that is the issue.

Definitely, had the same issue on my friends v max, turned out the earth line from the coil was high resistance, not broken as such but around 13 to 14k ohms resistance. That was enough to make the cdi throw a fit.

There is no vin for a bike from 1979, vin numbers did not exist. Where did you get the number from, it should be stamped on the top of the right hand side engine case. The frame will be stamped on the headstock as always, right hand side can be covered by powdercoat/paint etc or worn by blasting. There should be something visible. Mod note. I hid some of your frame number. Its only the first 3 letters and numbers you need for identifying the bike model.

Yep +1, I recently cleaned a set of vmax carbs for a friend. He said they were fine as was but as he was rebuilding the bike anyway I got him to let me have them for a few days. The rustycrap that had built up inside was surprising for a bike running ok. Especially when you start using compressed air to blow through, a couple of jets were blocked and needed a copper brush (strands of electrical flex) to clear them. Its running far better now. These are jets big enough to feed a 1200, just think how easy a 125 carb will clog.

Nice, longest I have done is 30 miles, that was doing several things in a loop, dropping some bits off for my parents, picking stuff up for neighbours. Spurious really and should probably have used the car, (its cheaper for a start), but it does feel good to get out in the breeze. Certainly de stresses me.

At least I can get all you lot back for volume, big multis with noisy pipes. Vmax can out shout em all.

Crikey what a pain in the arse, had a leaky rocker cover gasket on the vmax, finally got to sorting it today after waiting for weeeeeeks for the damn thing to show up. What a thing to fit, officially you take off the seat, airbox, carbs, fuel pump, drain coolant, header tank......continue till dead. So like any good home mechanic I cheated. If you whip the seat off (4 bolts) you can get at everything but you have to change the gasket without taking the cover off, just lifting it maybe 15mm. Its fiddly, and a few strategic blobs of yamabond (or red hylomar) to make it behave. But it is possible if your careful and patient. All done in the time it would have took just to get to the damn thing. Not keen on repeating it though, the gasket looks like its dead easy to snap.

Looking at cmsnl web site, very useful for this type of thing. https://www.cmsnl.com/yamaha-xs750-2-1977-usa-canada_model8628/partslist/F-04.html#.Xrpp425FyP- You can see in the drawing the plastic part of the master cyl is moulded in place, or at the very least not designed to separate. It comes down to how original you want to keep the bike, there are many options, fitting more modern units to different models that do the job. Any xs, xj, fj, even vmax its a long list. They may look different but front brake master cyl is only limited by chosen style and the calipers they opperate.

Hanging revs normally indicates a weak mix or an air leak. Could be both. Does it have a cv carb, could be a diaphragm (spelling?) issue if that's the case. Is it a new plug. I don't think I have ever known the float height be an issue unless a bike has had a carb rebuild. It either floods or works, once its set unless something fails, or some silly bugger fiddles with it.

Google, took 2 secs to track this down. http://xs1100.com/forum/index.php?topic=9802.0