Started a new thread for this one, probably best. Yesterday, sunday, had this 'S' reg fxr180 bought in with running issues. It had a Doppler air filter sellotaped and insulating taped and mastic'd onto the carb. And it couldn't pull itself out of bed, let alone down the road. It also had other issues like no speedo, or cable, front pads, loose rear wheel, missing bolts, the belt case only had three bolts holding it on. That sort of stuff. And the kid just paid 850 sobs for it. He had the standard airbox luckily, so i managed to re-instate that with the, i think, near enough correct airbox to carb rubber. The previous owner had used the rubber as an extension to the doppler filter It has the standard 20.5 Dellorto carb on it, it had an 86 main jet fitted when i stripped it. It also has a pm tuning pipe. I changed the rollers to 9.5gr, it had a mix of two different weights in when i checked, 3 heavy, 3 light. So, everything clean again, new rollers, airbox on with new sponge. Left the 86 main jet in, fired it up, bogging like hell and misfiring through the exhaust. Went through the jetting process, ended up with a 105 main jet that it liked, revved nice and clean with the wheel off the floor. Getting into the powerband well enough. Off for a quick road test. Took it for a spin, little hesitant for the first 30 yards or so, not getting into the powerband instantly, then picks up nicely and goes as it should. So i'm thinking that it could maybe go up or down one or two jet sizes from here just to get it nice and crisp, but the kid needs it for work in the morning and its now getting late, he has to come back over the weekend for other stuff to be fitted, like the new speedo drive, front pads, and gearbox bearings, so its good enough for now, safe to use, he aint going to be pulling any wheelies or beat stuff off the line, but it'll get him to work and back without any problems and i can fine tune it over the weekend. He duly came round to collect it, paid his money, I told him to take it for a spin then come back and tell me if he's happy. Came back with a huge grin on his face, thank you's all over the place, and off he goes for a cruise with his mates. Got home from work tonight myself and he's here waiting. The bike has gone back to bogging like a bitch. He was out last night, all going great, went to work this morning, all great, coming home it starts bogging like it was when it got here. And he says the exhaust is getting really hot, really quickly. I'm puzzled. Put a new plug in, the old one looked fine, but couldn't hurt with a new one anyway. No change, still bogging. Took the carb off, blew it through, changed the jet to a 100 from the 105, made it worse, went to a 110, no difference. Disconnected the choke, no change, checked the manifold, no splits, reeds?, no, fine, sitting nicely against the block no missing bits or splits. Put new reed block gaskets on anyway. Started the bike and disconnected the airbox from the back of the carb, made it worse, too much air now. Put it back on. Removed the air filter foam, no change, still bogging. Did a compression test, as its the only thing left that i can think off right now, reading 105psi. Now i know that that's a decent reading on a 50cc scooter but is it a good enough reading for this 180? Can anyone throw some light on what the expected compression reading should be from a good cylinder please? I have another new 21mm dellorto carb that i can try tomorrow, but i have a feeling it's not a carb issue.
Compression is very low for a 180, it want's to be up around 160+ at least. it sound's like the wrong carb, it should use a 90 main jet, 50 pilot, can't remember what needle/atomiser. 15.5g rollers. Drop the exhaust off and look up the barrel, piston condition.
Well, i spoke with several people about the compression values on this, and everyone said its too low. Looked through my tech specs as well and it says should be about 11 to 12 bar, thats 160 to 168psi. It's no where near that. So when the owner came round tonight i told him what i had found out via phone calls, and he went a bit pale. Off he went to the kid he bought it off, bit later they all came back, the previous owner ranting about what i charged for the work already done, ranting that it was running great when he had it and it must be something i done to it, but said nothing when i asked him why it only had 3 bolts holding the belt cover on and two bolts holding the side cover on and that he had bodged up the air filter with sellotape and mastic and insulation tape and the fact that the rear brake was useless and the speedo doesn't work. Of course it was all down to me, who, according to him, knows nothing about bikes, and is ripping people off saying they need this and that when they dont. I don't think he liked the fact that he's been caught out and it's come back on him. So he has now taken it away, because it only needs piston rings doesn't it, and he'll "fix it". Yay, space in the garage
@Marsh, the tech specs state the dellorto 20.5 as standard on these, which is what it had on it. Slide needle was on its lowest clip, put it back the centre. And it had the 50 pilot jet as well. But an 86 main, with a bodged up doppler filter, it wouldn't have it.
Well its gone now, its a dog with big fleas, what i didn't mention was that I think the water pump wasn't working properly either, that or a partial blockage in the system. Top water pipe was getting hot, lower pipe was still cold. Wonder if i'll find out if he "fixed it", I know there is an ebay seller that is selling piston kits for about 45 quid for it, but they are 65mm, not the proper 65.6mm, so if he does put that in there is going to be some piston slapping going on.
Best leave well alone, I've had shitters before were you think I wish I'de never set eyes on it, nevermind work on it!
