Iceni

I should have done it already, The weather has been naff, and I've spent 3 days brush cutting scrub off allotments.... I'll try catch a window of oppertinity to get the test done in the next few days. It's typical that you say your going to do something then spend 3 days waiting for the rain and wind to clear I have no garage, so anything on the bike involves pulling off the covers and working in the back garden, That and the fact I don't actually ride it yet mean it's not always at the front of my mind.

The engine shouldn't be seized. Give it a fuel change, scrub the plugs, and charge the battery. Bet it starts.

Right I got my adapter this evening. I haven't been able to do a proper compression test yet as I didn't have time to warm the engine. On a cold engine I was getting 7bar from both cylinders. I'll do a proper test tomorrow on a hot engine. I'll also attempt to start the engine on 1 cylinder and get a running pressure. Stock mixture screw settings on mine are 2 3/4 out.

Cool, I've orderd a convertor for the compression tester I have should be here by friday. I'll make sure you get that information Oddly I was chatting to a friend today about his bike, and he was having a similar problem. Turns out when he rebuilt it he didn't know the pistons were supposed to be reasonably tight and thought that when they went in easy it was a good sign lol.

If the static compression test was as low as that I would ask them to do a Leakdown test. It's similar to the compression test. They put each cylinder at TDC then pressure the cylinder to a set value and see how long it takes to drop. I'll see if I can find my compression tester and do the test on my own engine. It's only done 2K miles so it should give you a decent comparison. The lower value of the compression test may be because the engine has valve overlap. Where valves are still open at the start of the compression stroke. I don't have the information about this engine to know if it runs with an overlap I would suspect it shouldn't. 5 bar is very low. Thats similar to the compression I would expect to see from a lawn mower engine. It's enough to run, But it's not optimising the thrust of the engine to get more pop out of the fuel. I also want to hear the results of the soapy water test. It's a very direct test and will give you a 100% problem to fix rather than the compression test that tell you that there is a problem somewhere in that region! Edit found my tester but it needs an adapter for the bike. It only has 18mm and 14mm fittings. As soon as i get the adapter I'll give you the readings.

On your compression test both cyliners should show about the same level of compression. A slight difference is common. You should see between 130 and 150 PSI on the meter depending on the engine. If the compression is lower than 125PSI then you need to look into the problem. A cold engine will also show more air leak than a hot one in most situations... Metal expands and closes the cylinder head gap a little.

No both of my cylinders sound the same. I think you should do a compression test for sure. Depends on the engine, On a single cylinder engine you should be able to rotate to the compression stroke then it will be almost impossible to roll past that going by hand. On the twin you should struggle to get it past the compression stroke on either cylinder. You have to remember that you have 2 compression strokes to deal with and you may get a false feeling if your on the wrong stroke. As for the air escaping from the timing cover, If the cover was open then you should be able to feel air escaping. This is normal as the pistons have an effect on the bottom of the engine as well as the top where combustion happens. That internal pressure should not be escaping Via the timing cover tho. It should be going out of the crank breather located at the back of cylinder 2. That noise should also not sound like compressed air. It should be more like a subwoofer pounding. If you can hear a hiss it is probably a faulty head gasket and the leak is not comming from the timing cover. You can test this with some soapy water, Put a good squirt of washing liquid in a bucket then brush the mixture on the engine with it running.... Bubbles are bad.

I've just been given an XV 125 and am pretty up to date on the forums for these bikes atm. Firstly I have no idea about the Irish XV restrictions. The UK model has none, But the Irish one may still have restriction in place set by Yamaha. Check your exhausts. There is a restrictor ring that may be in place. Check your Inlet splitter (rubber part under tha carb) the 125 has a rescticted inner. And check the seal on that part. A leaking manifold will cause you to run increasingly lean as the bike gains revs and pull more air. I take it you have picked up the power up guide available on another forum. It goes into detail about jetting, Carb settings and generally getting more from these engines. I suspect you have a problem with the engine if it revs freely but gives no power. I would sugest looking at your valves first. They may have weak springs, poor tappet adjustment, or have a seating issue. Your valves may not present themselves as a problem because the engine seems to be running well. But even a slight leak will cause the engine to loose a lot of the top end, whilst seeming good at the bottom end of the revs. You can test the valves using a cheap compression testing tool. http://www.amazon.co.uk/dp/B0001K9TV0/ref=asc_df_B0001K9TV013080721?smid=A3P5ROKL5A1OLE&tag=googlecouk06-21&linkCode=asn&creative=22206&creativeASIN=B0001K9TV0 I've already had my xv125 over 55MPH with a failure on the manifold. I'm a reasonably normal build 12 stone. Also how much added weight does the bike have. Boxes, sissy bars, chrome addons all slow the machine. The best after market addon is probably a fly screen. It'll keep the wind off your chest and reduce the wind resistance your own body gives I plan to add one to mine. Have you checked your rear sprocket? If for some reason that has been made larger it will reduce your top speed and give more acceleration. The previous owner already made adjustments to the front sprocket so checking the rear is a good plan. I think the standard rear is 47 teeth I'll count mine for you tomorrow.

It's no problem. I have one for the GW hobby I do, But it has been used on many things outside of the hobby, mainly laptop screws. Mine is like the steel one shown in the video. It'll take bits from 0.5mm to 4mm. The GW one only takes 1mm to 2mm drill bits. Your also going to snap a few bits. It takes some practice not to twist. The best advice is get a stool. Get comfortable, then use both hands and just go slow. One you have a hole thats 5mm deep you can start to try working the key into it. If they key won't fit just use the drill at varying angles and ream the hole till it goes in nice and snug, If you get it perfect then you won't even need to glue it as using the key at an angle should start to turn the screw.

The pin vice is the drill It's a palm drill. The end that sits in your palm rotates. You cup the pin vice in your palm, and rotate it with your fingers. The drill pressure comes from your arm. Like i said brass can be hard to drill but your not going to do any damage this way. As soon as you try and use it you will see how they work. Just make sure you turn it the correct way. If you get one from games workshop they will show you how to use it, The GW hobby uses it to put small pins into metal models so they don't fall apart when they get glued. This is a different application for the tool but it shows the grip well.

Because that screw is so small i would use a cheap allen key to remove it. Get a pin vice. http://www.anticsonline.co.uk/2413_1_10903.html and a 1mm drill bit. Very carefully drill the screw, clean out the swarf. Then superglue a 1mm allen key into the hole. Just use a very small amount of glue on the very tip of the key. You should then be able to unscrew it. Just take your time, Brass can be hard to drill. Don't be tempted to get the electric drill out tho as 1 slip could see you messing up that very soft alu casing or if the bit jams kill the carb threads. There is a Games Workshop on church street in Macclesfield. They should have this pin vice in stock and it comes with some tiny drill bits. http://www.games-workshop.com/gws/catalog/productDetail.jsp?catId=cat470006a&prodId=prod1095460

Did you get this fixed? I've had mine in bits this week. Is the gear shifter feeling the same when you change gear? It might be that you have slipped a quatergear up on the shifter linkage. Drop the oil. Remove the sideplate clutch and outer basket. At this point you should be able to see 2 quater gears on the shifter mechanism. Make sure they line up dot to dot. If those dots don't line up you'll have to take the oil pump slave gear off. It's a circlip. When you do this bung a rag in the sump drain under the shifter mechanism. I allmost lost a clip down that hole!

The intake splitter is ordered. Sorry for any Yam lovers that stick to OEM I went with a chinese variant Cost £11 delivered! It's the XV250 pipe with no flow restriction inside. I've got a mate heading over tomorrow. Were going to drive down to the local bits shop. See if they have any handlebars that I like. I'll want new grips as well as the stock Yam ones are a little ugly. I need a tank protector as well to hide some zip damage. Today i reset the jet position. The plugs are showing it to be running rich on both cylinders, But thats been at idle with one mild reving I was fully expecting it to be lean with the split in the pipe. Once I have this part and I can take it down the lane and get some heat in it I'll make sure it's running brown. I also had a little power test earlier and managed to get the back wheel spinning on the grass in my back garden I've also reset the brakes. The rear brake pedal was set at a silly angle. So it's been dropped to be inline with the shifter. And I've sorted the play on the pedal so it comes on when i want it to rather than when you tap it! I also found out I can get to the tool box without needing to remove the seat. This means I won't have to carry a set of spanners in my pocket if i want to adjust on the fly. The last part I need is the sealing washer on the sump bolt. Mines got a little drip of oil (3 drops last night). Looks like I'm running out of excuses for not going and doing a CBT! .

I'm not sure. As far as i know the block has never been stripped so I don't think it's a bad mechanic. Perhaps it happened in the drop. The shift might have been landed on causing it to jump a tooth. The odd thing is I got the impression the previous owner had ridden the bike after the drop. I know the drop happened before I had even met him and that means if that is the case then it's been sat unused for over 8 years, with only a minor fault. Some people must have money to burn to leave a simple problem that long! I've also found a few more issues with the bike. The main one been a small crack forming in the rubber inlet manifold. I want to strip the carb at some point as well so I think i will replace this part with the strip down. I'm not sure if i can remove the carb without removing the tank. I'll so some digging and find out. If i can it should be a fairly easy job. I'll clean the jets, do the float tank then rebuild it to factory standards. I may also pick up a larger jet kit at some point so i need to know what the carb is like to remove. I think the tappets want doing as well so there is plenty to be doing. I've also decided that the sissy bar is going to go. I may get it stripped so i can put it back on at some point. It is the only bit of the bike other than the handle bars that I hate. The handle bars are also going to be replaced. There for want of a better word uncomfortable. They put my wrists at a funny angle so I will be replacing the whole bar with something lower and straighter. The bars are also slightly bent and I need new end caps. So a full replacement will work pretty well. I'm also thinking about adding a screen. Nothing big or fancy, Just a little wind reflector. It should help with the top speed, and improve fuel economy slightly. I'm going to keep an eye out for something that suits my needs. By the end it's going to end up looking half way towards a cafe racer lol!

I just stripped it this afternoon, Took off the clutch down to the spline, and the oil pump gearing so i could get into the gear selector. Turns out this bike was incorrectly put back together at some point. Part of the selector mechanism wasn't lined up dot to dot. I moved it over 1 tooth and it now selects all gears... so simple. LOL. The gear selector is not like the xv535 or xv1100 setups. On the selector arm you have the pawl, spring and quatergear. It also has an extended shaft with the oil pump gear sitting on the end. The quater gear links to the cam follower and arrestor on the LHS of the gear drum. The Quater gears line up dot to dot, thats where the problem was. The effect on the pawl was to place it lower than it should have been on the drum. Causing it to miss the upshift nubbin. I'm not sure why neurtal was still working TBF

Right I've been back into it. I think it's a bit of user error on my part about the gears. With the cover off and the engine off I can get the shift lever to go 1st or neurtal. If i try to go past neutral Up to 2nd then the Pawl extends to full extension. However the Cam follower holds neutral. I can see that it's going to full extension as the pawl linkage only has a range of movement limited by a hold cut inside a guide. I'm wondering if the gearbox is designed with beginners in mind and will not go to 2nd without enough drive speed through the box. I then made sure the selector drum was working, By spinning the Clutch houseing, And operating the Pawl with a screwdriver, all the gears will drop in with no force, and they all engage. Now I have a problem. I can take the bike back to the off road path, Go faster and see if I can get all the gears. This means me walking the bike out, And walking back. The problem been I'm less than confident. Added to that I haven't done my CBT yet. Or I can leave it for the time been, Get the CBT done, then have to deal with the problem as i take the bike to get MOT'd....

Might need a rethink then I'll strip out the clutch again this week. And have a good look at the linkages. I'm sure I'll be able to try something. I'll make sure the pawl is working. I didn't check that it was so it's worth a very close look

Yeah I got a friend to come over and take the bike to a local off road path. 1st is not a problem. When you try to select 2nd it'll just drop to neutral. As you push past the neutral position it feels springy. I suspect that is more the foot pedal flexing than movement in the gearbox. When we brough the bike back we put it on blocks to see if something was out of place. Even on blocks we couldn't get 2nd. He sugested it might be the clutch thats why we stripped it. When we stripped the friction plates out it was noted that the plates had the signs of been dry for a little time. There was rust in spots that I removed with wet and dry paper. I suspect the same is probably true inside the gearbox. If it frees up then I think it'll be fine. The rust was not flakey, It was hard surface rust, With no real penetration. I suspect if it can be free'd then any rust that gets into the oil will be picked up by the filter. It's going to need a couple of oil changes now I think just to be sure I'm running a clean engine. I'm hoping that the control rods are visable from the clutch housing. If they are then this nylon punch will be tapped a little on the rod as we try and drop it in second gear. It's either going to bind into 2nd, and require a stripdown. Or work. We should be able to get the correct control rod since 1st and second are opposite's on the same spline. I'm also hoping that 1st is the outer race and not the inner one. If 1st is the outer race then tapping into it should free it. If it's the outer one then I'll have to work somethign else out. It's been a few years since I stripped an engine and without a dedacated Haynes I'll be working on half the information I need with the XV 535 manual. I can't comment on 3rd 4th or 5th yet One at a time

Well I appear to have run into another problem. 2nd gear and up will not engage. 1st and neutral are fine. I'm doing the standard work arround stuff atm. I'll reset the gear change spline, check the clutch cable ect I've dropped the oil and taken the clutch cover off, The clutch has been stripped and cleaned. The next part of the work arround is to see if I can make it shift. I suspect it's minor corrosion on either the control rods and forks, Or the splines for the sliding gears. I'm going the easy route first. I've picked up a nylon dowel and will attemps to shock the control rods. If that free's second I'll class it as work complete after a bottom end flush. If the shock method fails it looks like i have to strip the engine to get to the splines. I may attempt a turnover with some thin oil. 0w30 or something similar to see if it can penetrate and free the parts. The good news is all the gears both plastic and metal inside the clutch plate cover look brand new. No wear on any bearings, and no metal in the oil. Whilst I'm doing this work I'm going to use a silacone gasket for the clutch plate cover. Once it's working I'll replace the gasket with the correct parts.

Chances are the brake/carb cleaner has dissolved the rubber pipework slightly. If you read the warnings on the can it probably tells you to avoid contact with rubber and plastic as it melts them. You should now replace all the rubber parts that have come into contact with the cleaner. Pipework could become brittle and or thinned, and increase your risk of a fuel leak. And the rubber diapram has probably lost it's shape and seal. Petrol will not disolve any of your components, The fuel assembly is designed to be resistant to it. It is not resistant to Tetrachloroethylene the active chemical in most carb/brake cleaners. Your carb should be fine. It may need stripping and cleaning. The Pump at the very least will need a new diaphram. Chances are it's cheaper to replace the full pump, Or grab a salvaged one.

It's wet today I've started to look into security. Picked up an Oxford Hardcore XL 1.5M from halfords. Should work as my main lock for the bike at home. I still need to pick up or make a sutable ground anchor. I'm also thinking about fitting a second hidden fuel tap. There is space on the fuel pump on the drivers side to do this. There was also a thought about rewiring the kickstand and cut out switch. If I make the cutout to the kickstand (up for on). And then rewire the kickstand to the cutout off for up it should confuse people if they try to drive it away. Basically you would need the kickstand up, and the cutout in the off positions to ride. The kickstand been down would be an unstartable machine. The Cutout on run would be a machine that stalls every time you pop it in gear. I'm going to investigate this sort of security in more detail later.

I finally got the camera out ( well my phone at least). Here she is!

Stainless has different properties to regular mild steel. It's a lot softer, and more ductile. This means components that take a lot of stretching warp very quickly in stainless, It also wears a lot faster. Regular mild steel is also very cheap. Something you might not know is you can force stainless steel to rust. If you contaminate stainess with regular steel rust then the stainess will begin to rust as well. This can be very important if your working in a location where there is a mixture of materials on hand. You can correct stainless after contamination with acid. And this process must be done if your welding stainless for the same reason. Copper grease also helps prevent this contamination. Parts where ALU and steel meet will cause the ALU to rust. This is a sacrifical rusting due to how the materials conduct electrons between themselves. This is used a lot in martime applications to make steel components last longer. But your bike may suffer, where you have an ALU block with steel bolts. You can counter it with copper grease. This is the reason your engine bolts are hard to remove. Even tho the bolts always come out reasonably clean looking.

The clutch is free I used your advice, ran the engine till hot, Pulled the clutch in then dropped into gear. The bike lurched and stalled. So i restarted it, And did the same thing again but on about 1/3 throttle. Bumped straight onto the clutch. I then sat with the bike ticking over for probably an hour, just moving up and down the garden. Didn't get out of 1st, but everything is working. Front brake is very keen. Rear brake is easy to control. The engine didn't stall or go flat once. I also found the saddle wasn't attached So 2 bolts have gone in to secure that. The bike has been given a coat of WD40. Figured it would help remove the spiders webs, and give it a little surface grease. It's also made the electric controls spring back faster. The only thing i forgot to do was take my camera with me! And by the time i got back into the house I was coverd in WD40.

Thanks people! I know i've joined the correct forum when people take not only an active interest, But they gang up on me because I've got no expirience and they know better