There is no screw missing , the holes are to set the powervalve up , but I assume you know that now . Bike didn't sound to me like it was carburating at all right to start with . Never seen a single front disc on a valve before .
Well, if anyone's reading the comments, it turns out in the end that the problem was not the exhaust blowing. The noise came back. Today I fully removed the exhaust manifolds and replaced the copper sealing gaskets. The noise remained. I wiggled the exhaust around and the noise didn't change, it was not blowing as far as I could tell. But, then I finally found what it was. A free coconut to anyone that can guess what the noise was.
It did sound like a blowing exhaust, and it's a sound I've heard on my F2 when the exhaust has not been seated properly. If your saying it wasn't that, then I would love to know what it turned out to be.
@@HUSKY7-1 That's where I thought it was coming from originally. There was another big clue when I thought about it. As I mentioned in one of the other comments the engine had recently had a full rebuild after a blow up. (Piston ring caught in a port). I didn't rebuild it. The nose was so loud I began to suspect the head gasket. Tightened the head bolts - still same noise. Checked barrel bolts - all of them loose! I think they must not have been torqued. Anyway, all good now, it went great at Prescott.
@@motorbikewhisperer I hope you had a word with the engine builder in the interests of ‘Black Box Thinking’ and sharing of information to avoid future failures. Glad you solved the problem
@@motorbikewhisperer I have a 31K 350 YPVS, luckily it's mileage is so low it isn't worn, I've seen many over the years that were a bit rattly. Just thought that was your problem, hopefully you didn't block the hole in the powervale body, that wouldn't be good 👍👍😂
I was going to say the kickstart, but I see you don't have one. Mine rattles quite a bit, along with the upper headlight assembly. That sounds a little too mechanical, to just be a vibration though. I also have my side stand touching the left pipe.
If that was my bike the head and barrels would be off.it sounds ok but sounds not good and crisp.even tho you fix that bad sound to me it lacking crisp power.if you take the barrels off check for play line the bottom of the piston to the bottom of the barrel see how much play there is if the is any.check for burns on the pistons under the piston rings. If you do do this soon as you take the heads off see haw much movement there is with the piston at the top.check small end bearings and big end bearings. The big end bearings it's the up and down play really you don't want any play even check the big end side to side when I check a big end I know when it's on it's way out.on my 350 first thing new pistons new small end new rings circlips clean every thing and the carbs air filter power valve setting timing jets in the carbs reeds every thing.if there is piston play rebore both barrels .even check the spark plugs if you buy new ones it happens to me new plugs were out.when I did all my bike and run it in it was a nice bike and I bought brand new All-speeds pipes.if you look after your bike it will look after you.nice bike
It's buried in the comments but this is a freshly rebuilt engine: new crank, rods, seals, pistons, rebore, etc. etc. It sounds great now - just check ruclips.net/video/G594ND7S1xs/видео.html
Love the work-safe rated Croc's 😂
Only the best PPE around here
There is no screw missing , the holes are to set the powervalve up , but I assume you know that now .
Bike didn't sound to me like it was carburating at all right to start with . Never seen a single front disc on a valve before .
Looks like the front end is swapped from an early TZR250
Well, if anyone's reading the comments, it turns out in the end that the problem was not the exhaust blowing. The noise came back. Today I fully removed the exhaust manifolds and replaced the copper sealing gaskets. The noise remained. I wiggled the exhaust around and the noise didn't change, it was not blowing as far as I could tell. But, then I finally found what it was. A free coconut to anyone that can guess what the noise was.
It did sound like a blowing exhaust, and it's a sound I've heard on my F2 when the exhaust has not been seated properly. If your saying it wasn't that, then I would love to know what it turned out to be.
@@IanNiblett I'll give it a bit longer and see if anyone guesses.
Powervalve connector piece not tight
@@HUSKY7-1 That's where I thought it was coming from originally. There was another big clue when I thought about it. As I mentioned in one of the other comments the engine had recently had a full rebuild after a blow up. (Piston ring caught in a port). I didn't rebuild it.
The nose was so loud I began to suspect the head gasket. Tightened the head bolts - still same noise. Checked barrel bolts - all of them loose! I think they must not have been torqued. Anyway, all good now, it went great at Prescott.
@@motorbikewhisperer I hope you had a word with the engine builder in the interests of ‘Black Box Thinking’ and sharing of information to avoid future failures. Glad you solved the problem
That sounds like piston slap, too much clearance between the piston and barrel. Powervales don't rattle. That hole is for setting the powervales.
It did indeed sound like something mechanical. It had just been rebored/new pistons so it was unlikely to be piston slap
@@motorbikewhisperer I have a 31K 350 YPVS, luckily it's mileage is so low it isn't worn, I've seen many over the years that were a bit rattly. Just thought that was your problem, hopefully you didn't block the hole in the powervale body, that wouldn't be good 👍👍😂
It had a fairly extensive/expensive rebuild very recently. It's started blowing again so this time I'm going to replace the copper gaskets.
@@motorbikewhisperer PJME.co.uk do them, they are pretty cheap
I was going to say the kickstart, but I see you don't have one. Mine rattles quite a bit, along with the upper headlight assembly. That sounds a little too mechanical, to just be a vibration though. I also have my side stand touching the left pipe.
Might have to clean your carbs. Does the bike run on points?
Carbs are clean - electronic ignition
By any chance what is color paint code and brand if it was repainted its lovely
Hello, yes I had it painted by a guy near me I'll try to find the code but it should be the proper Yamaha yellow.
Did you fit a brand new exaust gasget 1 thing you should always do if you remove exaust !!
Sounds like there's something stuck in your exhausts
Sounded like blown powervalve seals to me .
If that was my bike the head and barrels would be off.it sounds ok but sounds not good and crisp.even tho you fix that bad sound to me it lacking crisp power.if you take the barrels off check for play line the bottom of the piston to the bottom of the barrel see how much play there is if the is any.check for burns on the pistons under the piston rings. If you do do this soon as you take the heads off see haw much movement there is with the piston at the top.check small end bearings and big end bearings. The big end bearings it's the up and down play really you don't want any play even check the big end side to side when I check a big end I know when it's on it's way out.on my 350 first thing new pistons new small end new rings circlips clean every thing and the carbs air filter power valve setting timing jets in the carbs reeds every thing.if there is piston play rebore both barrels .even check the spark plugs if you buy new ones it happens to me new plugs were out.when I did all my bike and run it in it was a nice bike and I bought brand new All-speeds pipes.if you look after your bike it will look after you.nice bike
It's buried in the comments but this is a freshly rebuilt engine: new crank, rods, seals, pistons, rebore, etc. etc. It sounds great now - just check ruclips.net/video/G594ND7S1xs/видео.html
Fuel starvation