intermittant misfire

[wildchild74]

The resistors in the NGK one are wire wound whereas the Yamaha OEM ones are Carbon.

The carbon ones are cheaper to manufacture, but their resistance values can vary by 20%.
The wire wound ones are more accurate, normally within 5%.

The carbon type age badly and the resistance rises as they get older and coupled with corrosion it plays havoc with the spark, causing misfires, poor starting and all sorts of other issues

Be sure to clean the brass piece deep in the cap also. I usually spray the inside of the cap with WD40 before reassembly

If you put back the original caps with the NGK resistors pack the top of the cap with vaseline before replacing the rubber boot, no more water ingress.

Hi folks next update done all the above inc changing oem resistors for cleaned up ngk ones started it up with a loud pop now i remember i think petrol or somthing was dripping from the joint where the can joins the pipe thats y i turned it off the other day.... anyway as said started sweet as a nut and ran lovely not a chug anywhere went up and down the road sound no chugging so left it to idle n then it started chugg chugg but if i rev it hard theres no chugg....so guys whats the next step b4 stripping the carbs down....really do appreciate your help on this thanks
Gaz

[unfazed]

Did you use the choke when starting it?

[wildchild74]

Did you use the choke when starting it?

Yes m8 do you think that could have something to do with it n i may try draining the float bowls next
Gaz

[unfazed]

Sounds like blocked pilot jets.

[wildchild74]

Sounds like blocked pilot jets.

Is that strip carbs n clean then
Gaz

[unfazed]

I would think so, I normally use cellulose thinners to clean the jets as it will shift the crap in the jets. If you want to poke something through the jets to clear them or dislodge the crap, use brass wire as it will not damage the jets, since they are also brass, some will cringe as the thought of poking something through the jets, but brass on brass is fine.
If the bike is left on the side stand for a long period then the first carb to be effected by fuel evaporation will be 4 and then 3.

[wildchild74]

I would think so, I normally use cellulose thinners to clean the jets as it will shift the crap in the jets. If you want to poke something through the jets to clear them or dislodge the crap, use brass wire as it will not damage the jets, since they are also brass, some will cringe as the thought of poking something through the jets, but brass on brass is fine.
If the bike is left on the side stand for a long period then the first carb to be effected by fuel evaporation will be 4 and then 3.

Yeah that makes sense as it is on side stand all the time and 4 is coolest and 3 a bit warmer 2 n 1 red hot cheers
Gaz

[wildchild74]

I would think so, I normally use cellulose thinners to clean the jets as it will shift the crap in the jets. If you want to poke something through the jets to clear them or dislodge the crap, use brass wire as it will not damage the jets, since they are also brass, some will cringe as the thought of poking something through the jets, but brass on brass is fine.
If the bike is left on the side stand for a long period then the first carb to be effected by fuel evaporation will be 4 and then 3.

Hi m8 ive got 5ltr drum of mek cleaner that i use at work now could i use this on the jets and float bowls as long i remove any o rings n stuff like that....what im getting at is would the mek affect the brass many thanks
Gaz

[unfazed]

I have never used it, but it should be fine with brass and as you say keep it away from the rubber seals.

[wildchild74]

Right the plan for tonite was drain tank, drain fuel filter till I get new one, and drain down carb bowls but do you think I could budge those drain screws not a chance started to knacker one so I stopped so couldn't carry on with my plan of filling with fresh petrol and half a bottle of STP complete fuel system treatment b4 I start stripping the carbs down....soo is there a special screwdriver for these screws,can I get replacements n I'm sure I've read they shouldn't be too tight as the bowl will crack so do you think these have never been undone and drained thanks
Gaz

[darrsi]

The drain screws are made of soft cheese unfortunately.
Look on AJ Sutton website.

[wildchild74]

The drain screws are made of soft cheese unfortunately.
Look on AJ Sutton website.

Cheers m8y will do now
Gaz

[unfazed]

A good fitting flat screwdriver should do the trick has a bit more bite. They will loosen with a crack and frighten the crap out of you

Anti clockwise of course

[wildchild74]

A good fitting flat screwdriver should do the trick has a bit more bite. They will loosen with a crack and frighten the crap out of you

Anti clockwise of course

Lol cheers for that m8 I just need to find some clear pipe to fit on the nipples to go into petrol can as the bikes in the yard now n if I get petrol all over the floor the missus will kill me as that's where the dog plays/craps lol
Gaz

[wildchild74]

Hi guys would anybody have any links to videos to remove carbs at all cheers
Gaz

[wildchild74]

Right folks next instalment of the misfire saga.... drained 2 carbs n knackered carb 4 drain screw so couldnt drain it so went inside just to get away from it b4 i lost it...then thought f!@#k it and put in the stp n petrol and took it out gave it a good thrash now the misfire seems to be going but the revs seem to stick on at about 1500rpm resulting in no engine braking... will this go the more i use it plus will the treatment break down the blockage while its sitting in the carbs thanks
Gaz

[stevie-g1968]

have you adjusted the idle down, or did you turn it up to compensate for the poor idle issue you have had?
try turning it down to 1200 and see how it runs... the cleaner may take a few runs to fully shift any crap.
my mechanic told me to use injector cleaner in mine after a lay up, so ive done this the other day as my bike had no been out since last October and it runs fine.

[wildchild74]

have you adjusted the idle down, or did you turn it up to compensate for the poor idle issue you have had?
try turning it down to 1200 and see how it runs... the cleaner may take a few runs to fully shift any crap.
my mechanic told me to use injector cleaner in mine after a lay up, so ive done this the other day as my bike had no been out since last October and it runs fine.

Hi m8 unless ive knocked it while f-ing about round that area no not as im aware of n good news is ive drained carbs 3 n 4, primed them n letting them soak now overnite n will fire it up tomorrow n take out for a blast hopefully cheers m8
Gaz

[wildchild74]

Hi folks this is getting boring now i know but the saga continues ... broke my neck friday to finish early so i could get the bike out for a long blast the intention was wolverhampton, bridgnorth,telford n back to wolverhampton but only managed bridgnorth and back but what i did notice was the misfire is apparant up to 3.5k-4k rpm then it howls lovely right upto 10k rpm then loads of popping on the way back down the revs sooo took it to mechanic yesterday n cyl 1 was running 70° lower than the rest n he thinks deffo carb prob so ive brought a set off rmt on here n hopefully swap them over in the week n keep you posted
Gaz

[darrsi]

Hi folks this is getting boring now i know but the saga continues ... broke my neck friday to finish early so i could get the bike out for a long blast the intention was wolverhampton, bridgnorth,telford n back to wolverhampton but only managed bridgnorth and back but what i did notice was the misfire is apparant up to 3.5k-4k rpm then it howls lovely right upto 10k rpm then loads of popping on the way back down the revs sooo took it to mechanic yesterday n cyl 1 was running 70° lower than the rest n he thinks deffo carb prob so ive brought a set off rmt on here n hopefully swap them over in the week n keep you posted
Gaz

You're only on Page 2, we're more patient than that, try reading this one. 


http://foc-u.co.uk/index.php/topic,2066.0.html

[wildchild74]

Hi folks this is getting boring now i know but the saga continues ... broke my neck friday to finish early so i could get the bike out for a long blast the intention was wolverhampton, bridgnorth,telford n back to wolverhampton but only managed bridgnorth and back but what i did notice was the misfire is apparant up to 3.5k-4k rpm then it howls lovely right upto 10k rpm then loads of popping on the way back down the revs sooo took it to mechanic yesterday n cyl 1 was running 70° lower than the rest n he thinks deffo carb prob so ive brought a set off rmt on here n hopefully swap them over in the week n keep you posted
Gaz

You're only on Page 2, we're more patient than that, try reading this one. 


http://foc-u.co.uk/index.php/topic,2066.0.html

Lol m8 trust me this wont reach 42 pages it will be off to bike heaven way b4 then lmfao
Gaz

[wildchild74]

Guys ive taken the carbs off awaiting a set off rmt but while ive got access to it i want to check the cam chain tensioner while i can does anyone the procedure to remove,inspect and lubricate and put back without knackering the chain thanks
Gaz

[unfazed]

If there were no rattles when the bike was running leave it alone 

[wildchild74]

If there were no rattles when the bike was running leave it alone 

Hi m8 it does rattle a bit but not enough to warrant messing with something that could poss knacker the engine
Gaz

[unfazed]

Highly unlikely the tensioner is a problem, mostly like a wearing chain or valve clearance to big.

Cam Chains like drive chains do not wear uniformly they have loose and tight spots. This causes a light rattle especially on startup and the only know cure is to replace the chain.

What mileage is on the engine?

The tensioner is easy enough to remove if you still want to.

Remove the alternator/Generator cover.
Rotate the the crank anticlockwise until the T mark lines up with where the top and bottom crankcases meet.
Some will say you do not need to do this, but it is the best position to have the chain in when removing the tensioner.

Do not rotate the crank when the tensioner has been removed

Remove the 10mm bolt at the end of the tensioner. There is a ball bearing within the bolt, don't lose it.
Don't lose the copper washer on the bolt
Remove the springs (one is inside the other)
Loosen the two allen bolts and carfully remove the tensioner.  There is another ball bearing inside in the tensioner don't lose that either.
If your lucky the gasket will remain intact, if not replace it. It is probably best to replace it anyway.
Lift the ratchet and push back the tensioner.
Oil it up and with the ratchet held off the tensioner push the tensioner in and out of the housing a few times.

Replacment is more or less the reverse order of the removal.
Tensioner pushed back into the housing
Gasket
Tensioner body
Tighten the Allen bolts to 10Nm
Ball bearing
Springs
Push them in to the tensioner (You will hear the ratchet clicking over the ratchet teeth)
Put Ball Bearing into cap Bolt and copper washer on the bolt.
Put it on the tensioner and tighten it to 20Nm

Now rotate the engine slowly two full turns. You will probably here the ratchet taking up a little more slack.

You might as well check the valve clearances as you have the Alternator/Generator cover off if not

Put the Alternator/Generator cover back on and tighten the Allen bolts to 12Nm.