first fire up

[davecut]

I have now fitted my starter motor and repaired my starter clutch so its time to fire her up. The problem i am getting
is flames shooting up out of the carbs and popping sounds in the exhaust which makes me think i am getting sparks at the wrong time are there any tests for the sparker ecu box or do you just fit a new one and if so can you still get them or is my bike heading for the breakers yard. Any comments would be of great help. Cheers Dave.

[Rikugun]

I think you bought this as a non running bike (?) and if so I'd approach the problem assuming nothing. Or, assuming anything and everything is wrong!

A quick check with a timing light (if available) would quickly determine if the timing is right. Someone help me with this: aren't there marks for idle and/or full advance timing marks for the front and rear cylinder under the small inspection left cap?

You might go through some of the key ignition related connections to ensure they're correct. I don't recall if the coils can be connected incorrectly? If the multi connector plugs reach, you may have the front cylinder coil plugged into the rear cylinder  pickup coil harness and vice versa. Also, the TCI has 2 multi plug connections. Tragically, one is the same shape as the Regulator/Rectifier. Misconnecting those may damage the TCI.

Do you know if the engine is mechanically healthy i.e. good compression and no bent valves? I can envision scenarios where improper valve timing or bent valves can present with backfiring, flames, and other related drama. Not as likely but......

[jefferson]

I would bet more on the valve timing than anything else. Like RG mentions though, anything is possible with no history.

[fret not]

You shouldn't have backfiring through the carbs.  That indicates the cam timing is off.  Getting back fires (after fire) is not uncommon from the exhaust, and often happens when the ignition switch is turned on or off.

The ignition is a "wasted spark" system, so each cylinder fires as if it were on the power stroke, every 360 degrees.  If there is fuel available on the exhaust stroke you will likely get a loud bang through the exhaust system.

[davecut]

Yes jefferson and fret nut i am starting to think along the same lines as you, the guy i bought it off said it was a runner but all bikes were runners earlier in thier life and with the huge ammounts of orange silicon smuthered everywhere
i think this bike has had a very sketchy mechanical service history. I was hoping that the starter clutch repair and a
rebuild of the starter motor might see a running engine, but it seems i will have to dig much deeper first step is to buy a haynes manual. I think it might be easier to drop the engine out and go right through it, as it looks quite difficult to work on the heads with the frame rails in the way. I have found in the past that the time spent strugling in tight places its much quicker and more enjoyable with the engine on the bench. If you think i am talking rubbish then please tell me put me straight on the way to go about checking valve timing. Dave.

[Rikugun]

I'd only remove the engine as a last resort. Even then, I'd find out what was wrong prior to removing it. I think I'd check some simple things first like some of the ignition connections I suggested as it takes very little time and no co$t.

Compression and leak down can be tested with only spark plug removal. Valve timing can be easily checked with the engine installed. As a matter of fact, the same steps are required to check valve clearances which should be done on any engine with unknown service history as a matter of course.

One step at a time, don't panic just yet!

[The Prophet of Doom]

and valve lash is much easier with the engine in place.  Almost impossible with it flopping around on the bench.

[fret not]

A word of caution regarding the silicone sealer you mentioned: it can become lodged in oil passages and impede or stop the flow of lubrication if it gets loose inside the engine.  The main places to look are the engine covers where they mate to the crankcase.  Too much applied to a mating surface can get squeezed out as the cover is snugged up.  If you can see where it squeezed out on the outside it probably did the same inside.

The main concern I have is the plain bearings on the crank, both rods and mains, as they already have a history of failing if lubrication is insufficient.

[davecut]

YES FRET NUT I TOTALLY AGREE i dont like this silicon gasket maker i personaly use blue hylomar i have heard rolls royce us it so if its good enough for them it good enough for me, I also make my own gaskets, i buy paper cut them out and hole punch the bolt holes. I find it very rewarding. Dave.

[QBS]

You might want to seriously consider removing both engine side covers and removing any and all the silicone seal that you can.  Reseal with gaskets coated on both sides with heavy grease.  Good Luck.

[Walt_M.]

I would not recommend against dropping the engine. Even checking the valve clearance is a pain with it in the frame.

[Rikugun]

Agreed, valve adjustment can be a PITA but for me engine R&R is exponentially worse.  It's a personal thing and some may find one less objectionable than the other. I am guilty of projecting my adversity of engine R&R - especially for routine maintenance.

POD does make a good point though so I'm guessing some sort of fixture to steady the engine on the work bench may be helpful.

[davecut]

Hi rikugun yes i see where your coming from but it looks to me you have a top notch bike did you get it that way or have you put a lot of work in? My bike has had a very sketchy past looking at all this orange silicon smothered over it any way i want to get to know this bike and i am quite looking forward to tearing it down and sort of bonding with it.
This might sound crazy but bikes are a hobby to me and i enjoy working on them as much as riding them, I have
reasonable workshop facilities a compressor air tools and a MiG welder and most importantly a raised bike bench so
i dont have to bend down to work it makes the job so much more enjoyable. I recently did a top end rebuild on a Honda deauville with the engine in and wish i had spent an hour dropping the engine out. You see it all depends on the circumstances, just my view hope you can see my point of view. Dave.

[Rikugun]

Davecut, thanks for the compliment on my Vision. I too enjoy bikes as a hobby that includes working on them. The black '82 pictured in my posts was a non runner that had gone through several hands. I feel pretty lucky as it was 90% complete and showed low miles. I've performed every mandatory and many elective Vision upgrades. I've replaced, renewed, welded, glued, painted, persuaded, polished, hammered, cajoled, straightened, sworn at, and nearly cried my way to having a Vision that is fun and reliable. Much of this was accomplished with the help of this forum and the many gracious members who shared their experiences so thank you ROV.  :)

As I said to Walt, I am guilty of projecting my sensibilities when it comes to many things including engine removal.  :D But you did ask for comments. I think your decision to purchase a Haynes manual is a great start.  You mentioned dropping the engine and going through it. I tend to want to know what's wrong first.  Many have come here and said they were going to "go through the engine" or "rebuild" it. Few have completed that task. The realities of part availability and cost not to mention time spent researching can be immense.

I do appreciate where you're coming from but admittedly got nervous when we went from diagnosing back firing to discussing the finer points of engine removal without having made a diagnosis as to what may be wrong first.

[QBS]

Davecut, it sounds like you are just the man to be a successful and contented V owner.  Your shop sounds like it is well equipped to handle anything a V might throw at you.  Once a V is well sorted they can be very dependable and highly rewarding to ride.  My '83 was my primary transport for 10 years beginning in '84.  I certainly understand your curiosity about what makes a V tick (no pun intended).  For the most part, during those years I maintained and repaired my bike with help from my trusty Haynes manual and little else.  Much of what is now passed on to newer V owners I had to learn from scratch, no internet in '84.  There was a lot of bonding going on and a lot satisfaction gained from overcoming adversity.  I'm excited for you and know you'll enjoy the journey. 

[davecut]

Thanks QBS for your kind words it seems there are a few of you on here that are the mainstay rikugun , POD and yourself and the nice guy who gave me the planet wheel, but it seems most of you are in the USA, I put this down to the fact there are many more of these bikes in the USA than there are in the UK they were not a big seller in this country and i dont know why as on paper they were a great design with some big names being involved  in the design. Perhaps they were overpriced when new. Any way i have a couple of bikes i want to finish an xj750rl which is also a very rare model only 800 ever made and a Honda vt500 which has been hanging around much too long, so when i have cleared the decks a little i can get the xz on the bench and drop the engine out. So you may not hear from me for a while but i will be back as arnie said. Dave.

[QBS]

Dave, you're welcome.  Thank you for the kind words about our Forum members.  There are many more mainstays that observe regularly, but rarely post.  However, when they do it's usually to the benefit of all.  Interestingly, even though we have past and present V owners from many parts of the planet, NZ and AUS seem to be home to a disproportionate number of nicely modified and well ridden Vs.  I don't think that North American and European hot rodders, either cars or bikes, have anything on those guys down there.  Burt Monroe and John Britton are wonderful examples.  Never the less, well done and ridden Vs are found at many other places on the planet, mainly in North America and Europe.

I think that several factors conspired to doom the V.  A crash in the bike market, unforgivable factory defects, wonderful features that sadly priced it out of the market, and, it would seem, a target market that wasn't educated/sophisticated enough to appreciate these wonderful features.........these were significant marketing issues to overcome.  Also, during that time period, it seems that Yamaha's marketing plan was such that if a bike wasn't a home run right out of the box, it had a two year life span.  So, Yamaha quickly created some really neat bikes that didn't have enough development $ in their budgets.  Never the less, they sent them out door, warts and all, to disappointment, frustration, and eventually to what some call cult status.

[fret not]

I maintain the XZ should have been released as a 500cc and or 750cc, NOT the bastard size of 550cc which fits in no racing class without giving away a significant advantage.  About the time the XZ was introduced Harley Davidson cried foul with a congressman and got import duties  levied on anything over 700cc.  Harley's XR750 was WAY too expensive for the general market and their other 'bikes' were far larger displacement and didn't need protection.  Well, they did because they were not up to the Japanese standards of efficiency and not leaking, but they soon came out with their answer, a cleaner motor, the Evolution.  Still, the rest of the world that wanted to export to the USA had to put up with the 'rules' that Harley got put in place.  Therefore we have some "vintage" bikes in the 700cc and smaller range, our beloved XZ among them.

[jefferson]

Aren't you kind of forgetting that everyone made a 550 at the time and it was a very hotly contested class. I guess Honda was at the lower end with the Interceptor only being 500cc, but then everything started getting bigger as in 600 Ninja and the class has kind of stuck with that size since.
Americas cruiser mentality didn't help and it also wasn't a 4 cylinder.

[davecut]

Well fret nut isn't that a bit severe calling a 550 a bastard size Honda made some lovely 550 fours, surely its all about power to weight , feel, handling and whether the bike is aesthetically pleasing to you. Does it really matter what the numbers are. If you are worried how about 535 virago or 305 Kawasaki 851 Ducat i think. Cars seem to get a name or
a model number or my land rover would be called a 1951 not a freelander if you get my point. If you realy think it should have been a 750 then perhaps you should have been looking at a totally different model. I have owned a lot of different models in my lifetime but i do like shaft driven bikes and i also like v twins. So some of my favourites have been Suzuki's vx800 Honda's cx650 guzzi 750 breva and some 4 cylinder bikes Suzuki gs650gt yamahas xj750 which
i have at the moment and the original gl1000 with wire wheels a bit too heavy but i still had to buy one.
So i pose this question how would you design a bike i would personally like to see an offset triple with shaft drive
with cc around 800 to 900 have you seen the aprilia mana 850 vtwin with auto or manual gearbox quite an interesting
machine i think they have had problems with the gearbox but i am thinking i might like to own one one day. Dave.