don't use the BP. The "P" plug has an extended electrode, it's ground strap sits aproximatly 5mm further down in the combustion chamber, some engines this creates a clearance problem from the piston to the sparkplug, the "P" plugs are generally used in 4-stroke engines that are designed for this type of plug
What he said!
Although people do use the iridium BPR one on the 315 with reported success so it doesn't foul the piston on this engine.
I only mentioned it because mine randomly fell out somewhere the other week! Didn't notice until I had water in the gearbox, 3 oil changes later and I think I'm happy its survived fine. Replacements are cheap from Sandifords and can be fitted with a screwdriver!
I'm like you, not really an expert on bottom ends I'm afraid
Water could get into your gearbox if the seal on the shaft of the water pump impeller had gone or if you've lost the crankcase breather hose and its got in when pressure washing. Or maybe if the clutch side crankcase gasket has gone. I don't think theres anywhere else....
You'll have to pop out the seals and on one side there will be a circlip style thing securing the bearing that needs removing. Take that out and hammer from the other side. Do it in reverse to reinstall.
I find sockets work well as makeshift 'drifts' to make sure you are knocking it out via the outer race.
Are you new to trials or have you been bouncing bikes about before?
It seems more about technique than anything. That said my mates scorpa seems to feel a lot easier to bounce about than my 315.
You can get the different rear linkage plates from H and D racing or others that change the action of the rear shock a little making it a bit more lively.
The air inlet pipe should be on one of the nipples on the right, then the vent pipe with the slash in it goes between the remaining nipples, one on the right, one on the left. I can't remember exactly which one the air inlet pipe should be on, i think its fairly obvious but I'll have a check later.
Check you haven't pressed on the throttle cable when replacing the tank. If its not that check your fuel supply, make sure nothings blocked or pipes kinked, lack of fuel will make it run lean which will cause it to rev lots.
Edit: Just had a look on the parts diagram, the inlet pipe goes on the nipple you can't see on the diagram!
I need to check my manual more! Sorry my bad, i got my carb settings the wrong way round. Can't remember what the setting for the earlier carb is exactly but 2 to 3 turns sounds about right.
Apologies for the leading you up the proverbial garden path!
I would guess its the 280 cylinder head bored out to 300 at the factory. Have to agree that I don't think I've seen a more honest looking bike/ebay sale in months!
Depends how OCD you are! Once I know something is broken i HAVE to fix it, its a horrible expensive habit of mine. That said I rode for a year with half an inch play in the rear with no problems that I noticed. It was only when I measured the amount of play I realised the bearings were shot. Not even sure I can tell the difference now I've done it BUT I know its fixed
Everything you've said sounds fine. Lorica is less prone to cracking when dry compared to leather so they're actually a little easier to look after and seem to take a little more neglect before failing.
The rear shock linkage bearings on the 315 are prone to getting water in and rusting away. The up and down play should be no more than a few mm with good bearings, if its more than that I'd look at replacing some.
I've got a '99 and it doesn't have a reserve position so check before setting off! I reckon I can run for 2 to 3 hours on a tank depending on the workload.
A simple clean just involves undoing the bottom bolt and removing the lower half of the carb. Do this with the carb upright as on the bike and take note of which way round the floats sit in the float bowl as you lower the bottom half off.
With this off you can just spray carb cleaner or an airline through the various holes. I strongly recommend using eye protection at this point as the carb cleaner has a nasty habit of popping out of a hole you're not expecting it to!
For a proper clean you start unscrewing all the jets, the choke system and the fuel inlet (which has a little filter). Blow through everything with an aerosol carb cleaner or with an air line and reassemble. They are brass screws so don't over tighten them, just nip them up.
However there is a lot to be said for the old "if its not broken....."
What Fuel/oil Mix
in Yamaha
Posted
50:1 ratio (100ml oil to 5L Petrol) and I'd use a semi-synthetic oil.