Another "won´t start"

[Yami]

I had my bike for...just little over a week. Now it won´t start.
I changed the oil the other day and got to much in it and thought it depended on that
it wouldn´t start. But it wasn´t.

Starter goes and it sounds like now it´s coming but not. I´ve done about 4 cold starts
since I got it and it´s been harder and harder to start and now it wont start.
Before, when it got a little warm it was no problem to start again, it started immediately.

I checked the spark plugs yesterday and I think they were looking really good.
Replaced the airfilter today with a new one. Time to ride I thought.....

Searched here some and found others that had problems with this and it´s been suggesting
things like valve clearances, vaccum hoses. When I was attaching hoses today putting
the tank back on I got one hose left, finding no place to put it. I did put a mark on the
4 I loosened to remember which to be where and the 5th, I never loosened it.
As said, there is nowhere to mount it either. But it has been mounted before because there
is a mark on the end of a clamp.

If I follow the 5th backwards, the other end ends up just between the left carburator
and the left cylinder. There is one like it on the right side. This one ends mounted on
the fuelpump. Whats the left one for?
Is it a vaccum hose and where should it be located?

[Killerwhale]

I had my bike for...just little over a week. Now it won´t start.
I changed the oil the other day and got to much in it and thought it depended on that
it wouldn´t start. But it wasn´t.

Starter goes and it sounds like now it´s coming but not. I´ve done about 4 cold starts
since I got it and it´s been harder and harder to start and now it wont start.
Before, when it got a little warm it was no problem to start again, it started immediately.

I checked the spark plugs yesterday and I think they were looking really good.
Replaced the airfilter today with a new one. Time to ride I thought.....

Searched here some and found others that had problems with this and it´s been suggesting
things like valve clearances, vaccum hoses. When I was attaching hoses today putting
the tank back on I got one hose left, finding no place to put it. I did put a mark on the
4 I loosened to remember which to be where and the 5th, I never loosened it.
As said, there is nowhere to mount it either. But it has been mounted before because there
is a mark on the end of a clamp.

If I follow the 5th backwards, the other end ends up just between the left carburator
and the left cylinder. There is one like it on the right side. This one ends mounted on
the fuelpump. Whats the left one for?
Is it a vaccum hose and where should it be located?

One to the pump as said and one opens the tap. If you can start the bike in "prime" you´ve found the fault.

[Yami]

I had my bike for...just little over a week. Now it won´t start.
I changed the oil the other day and got to much in it and thought it depended on that
it wouldn´t start. But it wasn´t.

Starter goes and it sounds like now it´s coming but not. I´ve done about 4 cold starts
since I got it and it´s been harder and harder to start and now it wont start.
Before, when it got a little warm it was no problem to start again, it started immediately.

I checked the spark plugs yesterday and I think they were looking really good.
Replaced the airfilter today with a new one. Time to ride I thought.....

Searched here some and found others that had problems with this and it´s been suggesting
things like valve clearances, vaccum hoses. When I was attaching hoses today putting
the tank back on I got one hose left, finding no place to put it. I did put a mark on the
4 I loosened to remember which to be where and the 5th, I never loosened it.
As said, there is nowhere to mount it either. But it has been mounted before because there
is a mark on the end of a clamp.

If I follow the 5th backwards, the other end ends up just between the left carburator
and the left cylinder. There is one like it on the right side. This one ends mounted on
the fuelpump. Whats the left one for?
Is it a vaccum hose and where should it be located?

One to the pump as said and one opens the tap. If you can start the bike in "prime" you´ve found the fault.

You are a hero for a mess like me, my sorry eyes found it.
It certainly explains todays "wont start", but not day before yesterdays. We will see what tomorrows
says if I dare do it. The evil spiral of mistakes seems to continue.

[ekoja]

Yami...when mine wouldn't start I checked the plugs and while they looked ok and indeed out of the bike there was a spark, in fact they were stuffed.
New plugs and away she went. Got to be worth a try.

[Yami]

Yami...when mine wouldn't start I checked the plugs and while they looked ok and indeed out of the bike there was a spark, in fact they were stuffed.
New plugs and away she went. Got to be worth a try.

Thanks for the tip
I´ve been partly sleepless last night, thinking about the bike. It´s alright though, got
another one working. But I don´t like problems, they just have to be solved. I bought
new sparkplugs at my lunchhour, Denso was what I could get. The current ones is NGK.
Should have changed the plugs as soon I got the bike like I always do.

Finding out with KWs help it was a vacuum hose loose opening the tap. That maybe will
let it start tonight on the ON/RES-mode. Changing plugs can help me get it more willing to
do coldstarts, I hope. If not, I read about another alternative here, Trixy I think, having
same kind of coldstart issue. Buying shims, hmmm...well, have to learn that as well.

Trixy, if you read this, how did it go for you?

[Yami]

Guess what this mean?


Yes, seems problem solved with new plugs. Coldstart with choke and it started almost
right away. But you never know if the plugs just fixed it temporary so time has to tell
if it is a deeper problem.

Thanks for helping out.

[Yami]

The joy ended quickly.

This morning I fired it up, took some time again but I used it to go to work.
When work ended it was a pig getting started. Almost not succeded with it.

Something is trashing the spark plugs. We know that new ones fix it very temporary.
Myself and engine troubleshooting is not a good combo when I know to little.

Anybody having any ideas about it?

[Mincehead]

Tell me, are the insides of the exhausts black and sooty? I suspect it`s running VERY rich and fouling / sooting the plugs up Yami.

[Yami]

Tell me, are the insides of the exhausts black and sooty? I suspect it`s running VERY rich and fouling / sooting the plugs up Yami.

When you say "rich" I assume you are talking about fuel, not air.
Don´t think the exhausts are very sooty.

This is how the plugs looked when it wouldn´t start. The new ones I inserted yesterday have now the same look.




I am an amateur when it comes to engines, no doubt about that.
I have seen some sparkplugs before and I think thoose looks fine.
Maybe they are looking shit to you and I´m way out of it.
But running to rich, wouldn´t they have a kind of wet sooty look then?
Now it´s the opposite, maybe to dry?

Inspected the bike before and there is a new original airfilter. No mods at the airfilter housing.
Meaning all parts is there and no extra holes drilled. Even the foam is still there at the housings
outside. Housing is properly mounted on the carburettors and wont let any air get in that way.
Didn´t open up the carburettors though, but I probably couldn´t tell if something is "upgraded"
inside them anyway. The slipon is Lazer titanium ones.

Edit: this is a new kind of bike for me, twin.
Don´t know if it worth to mention, but compared to my Thunderace when thats starts on the
choke, it goes up to a a high rev and idles there by itself. The TRX doesn´t do that, you got
to stand there and hold the throttle a bit otherwise it will stop running. Not until it´s warmed
up it will hold the idle itself. Idle is ok then, doesn´t go up and down.
Driving it, engine goes smooth, I think. Never driven any other twin before.

Edit again: Was out comparing the soot in the Thunderace exhaust to the TRX´s.
About the same layer of black soot in both bike´s exhausts. With the diff that TRX´s soot
felt as it had a bit more grease in it.

[Mincehead]

No they look fine as you say Yami, so we should begin to suspect perhaps a fuel supply issue or an intermittent spark.
Try pulling apart and reconnecting all the terminal blocks and spade terminals of components that belong to the ignition circuit, the coils, the starter solenoid and the relays.
Especially check the terminal block that goes into the relay found on the front face of the rear frame H casting, corrosion of terminals is very common at that one. The side stand switch plus the clutch switch cut out circuitry is taken care of by that relay I believe.
Could also be that the choke needles in the carbs are worn badly (they are made from black nylon / plastic). Or perhaps there is some kind of choke cable adjustment issue?

[Yami]

No they look fine as you say Yami, so we should begin to suspect perhaps a fuel supply issue or an intermittent spark.
Try pulling apart and reconnecting all the terminal blocks and spade terminals of components that belong to the ignition circuit, the coils, the starter solenoid and the relays.
Especially check the terminal block that goes into the relay found on the front face of the rear frame H casting, corrosion of terminals is very common at that one. The side stand switch plus the clutch switch cut out circuitry is taken care of by that relay I believe.
Could also be that the choke needles in the carbs are worn badly (they are made from black nylon / plastic). Or perhaps there is some kind of choke cable adjustment issue?

Thx Mince, a lot of tip.
I think you as well has mentioned somewhere here in the forum that zero valve clearances makes the bike hard to fire up.
Also you said that when engine is warmed up, it´s easy to fire up because the clearances have increased by the heat.
So far this is how my bike behaves. That new spark plugs is making it easy to do a coldstart (first time) is a bit annoying
because I don´t understand how come. But getting hints about valve clearances other places as well I think I will forget
the spark plugs for now and start out doing the valve clearances check along with Mr Haynes.
I will also try checking the carbs with my greenie eyes and check out the rest you are mentioning above.
I´ll probably start doing it in the weekend. It´s gonna be fun. Wish me luck.

[Yami]

Valve cover went off today.
Measures wasn´t any good at the inlets. Couldn´t even get in the soft 0,05 feeler gauge.
On the exhaust there was one at 0,15 and the rest at 0,20.
So everything needs to reshim.

[Mincehead]

Ahaaa, well that`ll do it for sure.
Hopefully your valve faces and seats will still be serviceable. I can tell you one thing, that motor is really clean inside, the oil`s been changed regularly, hardly any staining from deposits left by dirty oil, a GOOD sign.

[Yami]

Ahaaa, well that`ll do it for sure.
Hopefully your valve faces and seats will still be serviceable. I can tell you one thing, that motor is really clean inside, the oil`s been changed regularly, hardly any staining from deposits left by dirty oil, a GOOD sign.

Hope you are right, I´m not really up to it going any further at the moment.
This was tough enough for a greenie. And I have a lot of work left, buy and install new shims, put cams together correctly
and check clearance again.

[Yami]

Do you have a cheap, fast to deliver site buying shims at?
I found Kedo, but it was only 3 of each in 48 sizes.
I need according to the table, 8 of 175 size, 1 of 170 size and 1 of 180.
Yamaha will be expensive as usual I reccon.

This was the valve clearance measures and shimsizes.
6 with <0,05mm had shimsize 194, 188, 192, 190, 184 and 188 installed.
1 = 0,15mm had shimsize 186.
3 = 0,20mm had shimsizes 182.

Edit: Didn´t found out how the micrometer worked so I had to borrow a digital.
It is differences in the measurements according to what it says on the shims.
So, I measured and got a slightly different shoppinglist.
5 of 175
4 of 170
1 of 165