85 250SX help

[drsung]

I picked up a pretty rough looking '85 250SX tonight. The guy said it was running last weekend and just quit, why do they all say that?

Got home, check for spark and gas and they were both good. Green Neutral light lights up. Battery and starter are good. Bike just turns over doesn't try to start. I Tried starter fluid and it does the same thing.

I decided to try and kick it over and I realized there was oil spewing from the top oil passage tube. I noticed the top bolt was missing. I see that the part is discontinued but I see they are available on Ebay so I will get that on the way.

My question is could that missing bolt cause the engine not to start? I am wondering if there is an oil pressure detection somewhere that could cause it not to fire. If not, any idea what I should try next?

[UPNATM]

I can't help you with your no start problem, but hopefully the previous owner saw like you did that the banjo bolt was missing, and didn't run your SX without it. Also, along with the missing banjo bolt you are going to need item # 20, and 17 in the pic below as well.

http://www.servicehondapsn.com/fiche...85&fveh=131334

[drsung]

Thanks for the reply. I found someone on ebay selling all 3 pieces for the bargain basement price of $16.99! At least the shipping was free. I'll get those installed when they come in and go from there.

I am a little stumped as I thought for sure it was going to be a spark/electrical issue. However, I don't want to do much else till I get the oil passages closed up!

[DickyDanger]

Does it feel like it has good compression? Wouldn't hurt to do a compression test on it.

[drsung]

It does have some compression, but to be honest it was a lot easier to kick over than my '87 200x.

I don't have a compression tester but I should probably pick one up.

Would something like this be adequate?

http://www.ebay.com/itm/Auto-Motorcy...item3f2294d21e

[DickyDanger]

That would work well enough to get a ball park idea on how much compression you have plus I promise you or your buddies will need it more than once.

[DickyDanger]

I also just noticed it looks like the head has been off and put back together with some sort of fast gasket or rvt material.

[drsung]

Yeah, I noticed that as well but it doesn't look like it was done recently. While looking at other Ebay options I saw some Harbor Freight models being sold as well so I am going to go by Harbor Freight today or tomorrow and see if they have one.

What's the ballpark on what it should read?

Also, would the missing banjo bolt affect compression?

[DickyDanger]

Im not sure of the ideal spec but good compression is over 100 psi.

[Jason125m]

The oil line being out of place will have no effect on your compression. However, it will starve your head of oil. If it has been ran for any period of time ( even 10 minutes ) in its current condition I would bet the cam / cam journals are shot. I personally would pull the head and inspect the cam/cam journals before running that engine.

[nstyle73]

He probably took the head off and either found a bent valve or a scored cam and the bolt got left out. Both are not uncommon issues. I think I have a set of valves you can have for shipping if that's the issue. I have boxes of SX parts that I don't feel the need to advertise for sale so, pull the valve cover, find out what your problem is and I'll see what I have to send you.

[drsung]

An Update... I got a HF compression tester and low and behold NO compression. I removed both valve inspection covers and both valves seem to be moving up and down normally.

I am trying to get the valve cover off and it is a no go. As previously mentioned it has some kind of goop gasket material holding it together. Anyone have any tips to getting it to break free other than getting a bigger ?

[Tacker]

Use a razor blade to cut the gasket enough to remove

[Frankencelery]

You will want to check valve lash. If you're seeing the valve go up and down and there's no compression at all, it almost has to be that the valves are misadjusted (or a hole in the piston). The procedure is spelled out pretty well in the service manual, but when the valve is closed, you should be able to get a .004 feeler gauge in between the spring and rocker. There's a possibility that someone cranked down the valve adjustment for who-knows-what reason.

BTW, that .004 should be a good start, but I'm not sure if that's the exact spec on the SX.

Also, as others have said, but I feel bears repeating, that tube supplies the oil to the top of the head. You shouldn't even try to start it with that banjo bolt missing.

[jb2wheels]

I picked up a pretty rough looking '85 250SX tonight. The guy said it was running last weekend and just quit, why do they all say that?[/URL]

Because they are liars!

That's one of the many flags:
"ran when parked"
"needs carb cleaned"
"just needs tune up"
etc

I hope it was cheap!

I've trusted and been burned enough to not to.