Will not start

[Romano]

If it's been sitting a while it may just be fuel gummed up inside your carbies.
Think about what sort of fuel they use in South America too..
If it's an ethanol mix fuel, you may find a lot of degradation of rubber o rings and diaphragms.
May be worth your while to just systematically go through the fuel path, dismantle the fuel tap( it only a couple of screws) then move down to the vaccum pump again 3-4 screws, and check and clean each component and fuel / vaccum lines.
As Alex said, purchase 2 of the KY-0570 Keyster carb kits as they come with all new seals, o rings, needles , emulsion tubes and jets for the carbies.
http://www.ebay.com.au/itm/262228282694

Thank you Guys im already looking into the carb rebuild kit will order them.
What is bothering me is the way this started i had cleaned out the carbs entirely assembled everything back and all was fine after 2 days the main fuse started blowing changed it a couple of times kept blowing it right away after checking all connectors cleaning them a bit and reconnecting its finaly stopped blowing the fuse the bike started fin but wouldnt keep running and after a couple of times starting it would start anymore.
i immediatly thought electrical (cause of blown fuse).
tried everything and now out of nothing it runs again.
PS: our gasoline here is 95 octane i think european grade.

[alextrx850]

id push towards an electrical Ground or earth wire to the frame for the fuse problem....mind that if your Rex was manufactured in 1996 ...it's now 20 years old.
I've always been an advocate of a light periodical spray of a penetrating oil over most of what can corrode.
Obviously NOT the wheels.
Also regular care and mainainence is kryptonite to gremlins too.
What year is your trx then Romano ?

[Romano]

id push towards an electrical Ground or earth wire to the frame for the fuse problem....mind that if your Rex was manufactured in 1996 ...it's now 20 years old.
I've always been an advocate of a light periodical spray of a penetrating oil over most of what can corrode.
Obviously NOT the wheels.
Also regular care and mainainence is kryptonite to gremlins too.
What year is your trx then Romano ?

According to my registration its a 2000 buit i checked the vin online and according to the inyternet its a 1998
i bought it last year at a police auction had only 6000 km on it it was impounded years ago and was just sitting at their impound yard the tank is really rusted on the inside thats why i put an inline fuel filter and regularly clean the carbs.
i think i found the problem of the main fuse blowing last night.
i was putting back the tank and noticed the wire bunch going to the main switch was damaged if i look at the location where its probably by the screw holding down the tank up front (right side) i was happy finding that problem at im 99% sure thats why the fuse kept blowing because the red(12v ) wire was damaged so it was probably grounding on the screw or frame.
thank you for all your advice my next step is to rebuild the carbs because im still having some trouble with cold starts sometimes it starts right away and sometimes it doesnt.
i will keep you guys updated on this.
thanks again.

[Mincehead]

Get that tank sealed as fine rust particles are buggers for accelerating wear in carbs.

http://www.frost.co.uk/por15-fuel-tank-sealers.html

[Romano]

Get that tank sealed as fine rust particles are buggers for accelerating wear in carbs.

http://www.frost.co.uk/por15-fuel-tank-sealers.html

does it really work? i was already looking at it but was thinking of getting another tank from the Netherlands i had found a couple online.

[cobbadiggabuddyblooo]

Good to hear your almost mobile again..
Just check with shipping on the tank if you go down that path.

Some countries have restrictions on things like 2nd hand carbies, fuel tanks.
Ive been stung with both.
As mince said , use tank sealer and if done correctly will sort the rust issue on your tank.

[Romano]

i think i will go for the tank sealer and then after that the carb rebuild kit.
Thanks for all the advice Guys apreciate it.

[Mincehead]

Roman there`s a LOT of different tank sealing resins out there. I`ve also heard very good reports about this one too:

http://kreem.com/fueltankliner.html

It may be down to availability where you are or import some.

[Romano]

Roman there`s a LOT of different tank sealing resins out there. I`ve also heard very good reports about this one too:

http://kreem.com/fueltankliner.html

It may be down to availability where you are or import some.

thank you mincehead,

i just ordered the por15 last night from amazon it will be shipped to me by sea so it will take a week or 3 before i have it.
ill update you guys when the job is finished.

[Mincehead]

It`s good stuff, the Classic`s boys use it a lot on old tanks. Follow the instructions carefully though.

[Romano]

the bike is acting up again.
after it started ok for a couple of days its now backfiring out of both carbo and exhaust pipe
almost doesnt wanna rev doesnt idle sometimes it even backfires hard enough that it blows the carb of from the rubber connector to the manifold.
Please help help help im out of ideas it drove perfect and now all of a sudden this.
im really getting fed up i love this bike but it doesnt seem to love me back.

[Mincehead]

Hmmm, do you use choke to start the bike from cold? I`m wondering if a worn choke needle is the problem, not coming off when you return the choke knob to the closed position.
Here`s what the plastic `needle` looks like, they do become notched and compromised over time:

http://www.ebay.co.uk/itm/Yamaha-TRX-85 ... SwstxVVIoQ

Did you check the electrical connections to the coils, all the multi blocks under the tank etc for signs of corrosion, especially any from the ECU / ignition? To be honest it`s all about working methodically through things. If the carbs are being blown out of their rubbers it`s more likely to be an intermittent spark allowing fuel/air mixture to build up unburnt and then when a spark does occur it`s explosive enough to blow the carbs from the inlet rubbers. Try taking one spark plug out at a time, Crank the bike over with the plug held against the engine and watch to see if the spark is intermittent or constant. Do this on both plugs, if the bike starts up and runs on one cylinder that`s ok as you`ll be able to observe the spark better on the plug you have out.

[Romano]

good news the TRX is up and running again it seemed to be the new iridium sparkplugs went bad i put back the old ones and vroooom its started and ran smooth.
Also treated the tank with POR 15 stuff is great i recomend this product although the coat itself wasnt really enough i could have used a litle bit more.
none the less im a happy rider once again.
Thanks Mincehead thanks Cobbadiggabuddyblooo thanks Alextrx850 thanks you for all your help and advice.

onto my next question i have my second gear slipping pulls great in first and great in 3rd and all other gears but second is slipping as soon as i try to gas it.
what your advice on this ??

[Mincehead]

You`re welcome Romano.
Oh but the second gear jumping, not so good. It sounds like rounded dogs and / or pockets on the pinion. If you hold the gear lever in second with your foot, does it still jump out of gear, are their any accompanying nasty noises?
As for the iridium plugs, that`s unusual but not unheard of, poor batches of plugs do happen although in over 40 years of riding and fettling bikes I`ve never experienced it myself.

[Romano]

It doesn't jump out of gear it's just slipping just as a chain would slip over the sprocket