1988 VTZ250 possible seizure

[Isaci]

Hey guys,
I had just finished accelerating on the motorway when I noticed a large amount of smoke coming from the exhaust followed by a gradual loss of power. After I first stopped the bike would still start for as long as I held on a bit of throttle but the increasing resistance within the engine slowed it down an it now wont even start.
I had filled up the bike with fresh oil the day before and the oil light was not on so I assume it isn't just lack of the stuff.

Any diagnostic help would be greatly appreciated as I cannot afford to take it to the shop. I'm fairly confident in my ability to fix anything as long as I know where to start

[Tazz]

Get yer spanners out and start pulling it apart then post up pics of what you find.

Should be a heap of vids on youtube that will help when needed.

Good luck!

Check you haven't put too much oil in as well.

[iranana]

Hey guys,
I had just finished accelerating on the motorway when I noticed a large amount of smoke coming from the exhaust followed by a gradual loss of power. After I first stopped the bike would still start for as long as I held on a bit of throttle but the increasing resistance within the engine slowed it down an it now wont even start.
I had filled up the bike with fresh oil the day before and the oil light was not on so I assume it isn't just lack of the stuff.

Any diagnostic help would be greatly appreciated as I cannot afford to take it to the shop. I'm fairly confident in my ability to fix anything as long as I know where to start

I'm no four stroke doctor, but lots of smoke = burning oil = (possibly) fucked rings. I don't really see why a seizure would cause it to pour out smoke (unless the seizure destroyed a ring). Seizures generally happen from running the engine too hot, for which there can be a few causes... running lean, advanced ignition, incorrect cylinder to bore clearance (not likely in your case)... Maybe you holed a piston, even. Before you get the spanners out and pull anything apart, get a torque wrench and a workshop manual. No point taking it apart if you can't put it back together correctly.

If it has indeed seized then (depending on the damage) you'll need to have the cylinders honed and the pistons cleaned up, and you'll need to replace the rings. At the worst you'll to bore to the next size over and fit new pistons/rings. Pull the heads, take some photos and post em up, then we can be of more help.

[gammaguy]

Drain the oil....... See how much comes out.... Make you you did not over fill it

Also check the air box... If it is full of oil, you probably did

[SNF]

Check out some Honda forums, there's boud to be some VTR specific ones. +1 on the manual, the specs are important.

Its pretty easy to pull apart, just start at the top, tank cover off, fuel tank out, carbs out etc etc. Take pics of the complicated stuff in stages, label everything. Take your time, don't rush it, have fun

[tigertim20]

how many km on it?
the VT250's of around that era are famous for running big ends when they get to about 35-50k on the clock

[F5 Dave]

it probably isn't worth fixing. Not being harsh, but sometimes its best to walk away & start saving. If you find another engine cheap you may take a punt, but it may be afflicted the same. New parts will easily exceed the bike's value. Sorry.

[Akzle]

check the valves on the cunt. Not too scary.

But yeaah.

[FJRider]

After I first stopped the bike would still start for as long as I held on a bit of throttle but the increasing resistance within the engine slowed it down an it now wont even start.

I had filled up the bike with fresh oil the day before and the oil light was not on so I assume it isn't just lack of the stuff.

You knew it was serious ... (you must have) ... but you persisted .. and totally fucked it.

The oil light shows (usually) low oil pressure ... not much oil is needed to keep minimum oil pressure.

Did you check at all for any oil leaks since you replaced the oil (and filter .. ??)