is it possible to get a slightly larger piston/ring set so you dont have to get the jug honed? I was thinking of measuring mine with a caliper and buying a kit that fits to the specifications i measured. tips appreciated
Not really. Pistons and rings only come in standard step sizes, so the jug needs to be bored to match. It's not an expensive process, typically, whereas a custom piston would be really, really expensive. Plus, unless you have a decent set of bore/telescoping gauges and know how to use them, which most people don't really, you're not going to get good enough measurements to size a piston. Boring also takes care of any out of round or taper that the cylinder may have ended up with over the years.
well, i guess the lack of responses means no one has any idea how to help me. It's a moot point now anyways, bike is wrecked right now. some jackass 16 y.o. kid pulled a left right in front of me (me traveling at 40 MPH) and i ran right into his passenger side. gotta admit tho, that bike is a tank, didn't bend the frame or forks. Needs frnt whl, hanlbars mirrors, levers, gas tank, headlight bracket, outer cases (impact cracked both sides), and some other stuff. still starts right up tho.
Glad ya mostly walked away. Given the engine problems you've had, maybe time to part this one out and start over. Can't explain the drifting valve guides.
These bike's are realy bulitproof, anyway glad you walked away, as for the guids the head was most likley damadge or the guids incorrectly installed
I wanted to put the cylinder and piston on today, I checked the new piston pin on the contacting rod and there is lateral play, up and down. Yamaha doesn't seem to list a small end bearing or show one. http://www.partspitstop.com/oemparts/a/yam/50042caaf8700209bc789d04/crankshaft-piston So do I have to replace the connecting rod?
Yeah, you do. No small end bearings. The wrist pin could also be the culprit - pull it out and check it with a mic or calipers or something to see if it is still round. If you can find the spec for the small end, you can do the same to the con rod. Any of the interface surfaces could cause that play.
Thats with new wrist pin. Rats, not sure what to do now. I already paid to much for the bike. Do I dig deeper or just put it back together and ride it it till it blows.
How bad is the play? Mine has a small amount and it still runs fine. Hasn't gotten worse in 2k miles, really.
There is about .010 play. You can see scoring on the bearing. A friend of mine a very well respected motorcycle mechanic thinks he can fit a new bushing, thing is if there is a bushing it's not bronze, a magnet sticks to it, there is a lip but maybe only a couple of thousands. So I'm not sure if there is a bearing there.
Hi this is my first post. I just got a 1997 XT350 the other week and have been cleaning it up and making it road ready. I was noticing when I ride it that the neutral light doesn't come on when it clicks into neutral. I'm wondering what this could be. Any ideas?
wow, 10 thou is quite a bit. Rod bearings are typically some sort of alloy, not bronze. Also, I believe the rod is ferrous, so that would affect magnetism. you'd probably have to bore out the rod, press in a bearing of some sort of hardened metal, and then reassemble, at which point you may as well put a new rod in. If he's got a way to try it, it probly wouldn't hurt, though. Article on engine bearings: http://www.turbomagazine.com/tech/0801_turp_engine_bearings_garage_tech/ Burned out bulb, bad wiring, or the switch is damaged or worn out. It's not a complicated circuit. A little quality time with a multimeter should find the problem in no time if it's not the bulb.
Decent advice I appreciate it. The previous owner had some brushguards installed and then he wired in extra turn signals (no clue why) and I'm guessing during all that he probably knocked something loose. I'll post a picture of the bike here in a few.
See if you can have it bored out and install a bushing. Might cost ya a bit, as the machinest would most likely have to press the crank apart to line up the rod. I had some small play in mine, with a new wristpin. I assemled and nothing has happened in 1500km. A new crank with rod can be had here, doesnt seem to expensive for what it is, if they really stock it, the partno seems discontinued: http://www.ronayers.com/55V-11400-02-00-P3989878.aspx
Well if I go through the trouble of removing the rod I may as well get a new one. http://www.boats.net/parts/search/Yamaha/motorcycle/1988/XT350U/CRANKSHAFT - PISTON/parts.html I'm just nerves about what i'll find in there. My two mechanic friends said with a loss wrist pin you will hammer the motor to deaf. The wrist is pounding on the crank may take awhile but it can't be good.
I have a 1989 xt350 that I'm parting out. Everything is there EXCEPT front wheel and forks. You may email or text me for pics ......whittrated@yahoo.com. OR 254_708_4860,Phillip
