conizme

Cheers buddy, will have to find a compression tester and get back to you!

Ok, thanks for your help, I will try and get a compression tester asap. What are the compression values supposed to be? The spark plug from the rear cylinder is a normal colour however, could it still be running lean?

Good to know, thanks mate. Just wondering why it doesn't happen with the rear one? And what would you mean by trimming 10mm off? Trim it on both ends? Sorry haha Also worth mentioning that the Front HT Lead has always been loose, but I can still hear a click when I push it on.

The plugs have the right leads on yeah, and the spark plugs have the correct gap. Something I noticed this morning, when I can get the bike started, if I put my hand over the front exhaust (the black sooty one) and rev the engine, a browny black fluid gets sprayed over my hand. It doesn't smell like petrol, so I'm not sure what this is, could it be oil? Or just water and carbon? This doesn't happen with the rear exhaust.. The front spark plug didn't seem to be oil fouled.. The bike makes a popping sound on deceleration, and sounds like it misfires on acceleration in the low revs.. Could the spark plugs be too hot or too cold?

As I said in the original post, I did try the old spark plugs, although this still didn't work, and in fact it seemed like it had less chance of starting. I more had the iridium ones for longeivity as they last a bit longer and I found a good deal. The bike started perfectly before changing the plugs, now it doesn't like to start on either pair.. Doesn't sound like a carb issue to me. I don't have a compression tester no, do you think the compression may be low? What would average compression be? It should be wise to mention the bike is only just about to touch 7000 miles, but it was rarely run by the previous owner. Thanks for the help so far by the way, appreciate it. I hope I'm not about to open a whole can of worms haha.

Yes, both the pipes get hot, although only the front one smokes when it is cold. It did this before I changed the spark plugs and this new starting problem came about though, so I don't know if a problem had started before and this is unrelated?

Thanks for replying, I think it's firing as I can feel pressure coming out of the pipe, and I'm fairly sure it gets hot yeah, but I haven't tried to touch it haha Edit: Just left the bike running, and both pipes do get hot.

Hi guys, for my first post I've got a problem for you, to do with my XVS 125. So last night I was changing my standard plugs (they were in good condition, just for longeivity) to some nice fancy Iridium ones, which to my suprise, caused the bike to fail to start with the starter motor. I checked the plugs to see if they were sparking and they both were, so not sure why this was happening. I bump started the bike and it fired right up, then turned it off. After this it started on the starter motor fine about 10 minutes later. The problem, is that this morning I tried to start the bike again with the motor, and it wouldn't fire. I tried bump starting it for a good 10 minutes and it just would not start. I thought I could fix the problem by changing back to the old plugs, which also didn't work, and if anything made it worse. In the end I put the new ones back in, pushed the bike to a hill and bump started it down that, which fired it up, although it didn't sound as healthy as before. (Excess fuel burning off maybe?) After a couple of minutes it sounded like it used to and I thought all was well. (Apart from now it has a sound coming out of the rear cylinder's exhaust, almost like flopping a piece of stiff card, like a 'wop wop' sound) Also noticed there is barely any carbon build up on this exhaust, where as the front one has plenty, although this was like this with the old plugs, and while the bike is cold, no smoke comes from the rear cylinder's exhaust, it all comes out the front. (Misfiring before perhaps? Just not as severe?) While riding the bike now, it definitely sounds like it struggles sometimes, and only has a top speed of around 50mph if I rag the absolute tits off it.. it's like it's misfiring, and I seem to have lost a bit of power. Also on deceleration in the higher gears it can make quite a lound gurgling or popping sound. So, I'm wondering.. What could cause this problem? It sounds electrical to me, but I don't have a clue about the electrical side of bikes Thanks in advance!