YPVS TONE

According to my NGK book XJ600S/N Diversion 1992 to 2002 should have CR8E fitted as standard. You would have trouble fitting the B6HS as it has a 14mm thread where as the CR8E have a 10mm thread. Tony

Sounds to me like a fueling issue if you say you sprayed carb cleaner in plug hole and it run. Check to make sure jet in floatbowl for choke is clear . Try blowing down hole "B" in oldgitonabike's picture you should be able to feel air coming out of "A". If not the choke jet is blocked. Try soaking in carb cleaner or if it is stale fuel which has gummed up boil a kettle and pour hot water in the float bowl and let it stand for a while and see if this melts the gum, making sure you rinse out floatbowl with carb cleaner afterwards. DON'T start poking bits of wire down the jet or you will enlarge the jet.

Have you actually checked to make sure it has enough oil in it ?

Yamaha YP125E Fork Oil Qty : 125ml to 130ml per leg of 20W fork oil.

Are you using a torque wrench to tighten the nuts in a criss cross pattern and to the proper torque which should be 22nm or 16lb ft.I usually start of tightening to a lower setting in a criss cross pattern i.e 10nm or 7 lb ft before tightening to the final figure and checking again after the engine has got up to temperature and cooled down. As mentioned get the head checked to make sure it isn't warped and make sure the faces haven't got any old gasket left on them before putiing on the new gasket. You shouldn't need any sealant on the gasket providing the head isn't warped.

Check the coolant level in the expansion tank when the engine is cold then again when the engine is hot .You should find the level has gone up in the tank when hot as the coolant expands in the rad when hot and transfers it to the expansion tank then draws it back into the rad when it cools down.

Sounds like the pilot jet is blocked. Unscrew it and you should be able to just see through it. If not try blowing through it in reverse direction of flow with compressd air or aerosol carb/contact cleaner.

Remember on the old type 6V bikes with direct lighting you have to have a good battery and in circuit otherwise you will get the problem of bulb blowing and excessive voltage.

Blown bulb ? Also try disconnecting the wire that goes on the neutral switch and connect it to earth. If the light comes on it must be something to do with the neutral switch .If it doesn't you have a bulb or wiring problem.

I think a thermo sensor is linked to the carb heater to prevent carb icing.

If you prise out the rubber cap from the very top of the fork where it goes into the top yolk and find a large hexagon bolt I'm sure these are 1979/1980 RD125DX/RD200DX forks. Tony

The forks look like late model i.e 1980 RD200DX . Can you measure the diameter of the stanchions as pretty sure they were smaller diameter then the RD250 and RD400. Tony

Was it running ok before the jets were cleaned? Did you remember to reconnect the vacuum pipe from the inlet manifold to the fuel tap? I think there is an air screw on the top of the carb at the very front. Usually this is preset and best left alone but if it has been played with the data book I have says screw it in till it is LIGHTLY seated and back out 2 turns.

Have you tried pushing down on the seat while trying to turn the key. Don't force the key as it will break inside the lock. Tony

I seem to remember on my 1979 DT125MX that there was no adjustment for the oil pump cable as there was a self adjuster in the junction box under the tank which automatically took up any freeplay.I seem remember this had a cover on which you can take off to check and see if it is working OK .Tony

No cynic You are not the only one who finds this irritating. I suppose now we have some decent weather this will bring out the drugged up mindless chavs who drive around in their souped up Vauxhalls and Peugeots with go faster wheels playing this repetitve crap. What gets my goat is the Police are quick enough to nick some biker because his exhaust dosen't have the correct stamp on it irrespective of how loud it is. But they never seem to pull up these dickheads with their loud exhausts and music??? blasting out through their open windows. I personally think this is victimisation towards bikers. Tony

The vacuum type tap you have operates from a vacuum from the engine inlet manifold that is why you should have the pipe running from one of the inlet stubs to the tap. So when the engine is running fuel flows from the tap in the ON or Reserve position. When you stop the engine the tap shuts the flow off. In normal use you leave the tap in the On or Reserve position. The Prime position is for when you have drained the carbs or run out of fuel and is used for initially filling the carbs then should be put back to On or Reserve.You can check the tap by taking the fuel pipe off the tap and connecting a pipe onto the vacuum stub on the tap and sucking on it with the tap in the On position you should have a flow and should stop when you stop sucking. Not sure what sea foam is but I would try draining the carb floatbowls first .Tony.

When you say it is fully closed after 7 mins is that with it still in hot water or after you take it out? I have just tested a spare new thermostat I have for my RD350LC2 that opens at 71c and after you take it out of the hot water it is closed within 1 minute .The other thing to check when it is closed look around the valve in the centre and make sure you can't see a gap .Tony

Are you saying that the fuel doesn't flow from the tap in the ON position with the engine stopped ? If so this is correct as the tap is vacumm operated and should only flow in the On/Reserve position with the engine running.If the vacumm line is missing from the fuel tap to the stub on the inlet manifold then this is your problem and you won't get fuel flow from the tap in the ON or Reserve position with the engine running .Tony.

Were they located in the barrel when you took it off, if so did the people who did the rebore take them out ? Tony

The wiring should be already there for brake light and indicators. Have a look at the loom near the kickstart area and see if you can see a Green/Yellow and Brown wire which will be for the stop light switch and look at the front and rear of the loom and see if you can see a Dark green and Dark Brown wires which will be the feed for the Left and Right indicators which then go to Earth/Black wire .Tony

Seem to remember on the XS250/400 the LT and RT marks refer to Left and Right TDC (Top dead centre) positions. You should see LF and RF marks which is when the points should begin to open with the engine stopped (static)or when strobed with the engine ticking over. Tony.

Have you got a owners manual for the bike ? If not try here : http://www.ymenvom.nl/new/manuals/U5DME4.PDF The oil light is an Oil Level light Not an Oil pressure light. To check the system is Ok put the kill switch to the Run Position, Turn the main ignition switch on making sure the engine is in neutral and press the starter switch. The oil light should come on then go out when the engine starts and you release the starter switch. Remember as it is an oil level light it can come on when braking or accelerating hard as per the above manual page 3-3 .If the light comes on under normal riding check the level via the sight glass or dipstick .Tony

The cover usually has a very small cutout at the bottom to let water/condensation out where it covers the rotor.Did you look behind the gasket. You should also find one in the oil pump cover at the bottom. The bulletin I got as a job lot in a folder off ebay. Not sure how to post a picture here but if you send me your email address to [email protected] I will see if I can send you a picture .Tony

I found an old Yamaha service bulletin for the DT100/DT125/175 that says they discontinued the case with the breather vent with one that has a groove cut in it. If you remove the cover you should find a small groove cutout at the bottom of the case to let out any water / moisture. Tony.