Need help and Advice on pulling an SX motor out of its frame.

**bigredhead** · 06-13-2005, 11:01 AM

When you say " No compression " .. have you put a pressure gauge on it yet ?

The kickers on the 85's are prone to failure from what i've read..... does the electric start still turn ? if it does.. open the side cover ( with engien IN frame ) and check the starter gears before you take the time to remove the motor.

I bet the head pipe bolts break when you try to remove them !!!!! don't need that " Head " ache !! lol....

if you put it in gear.. to bump start it... does it lock the rear wheels until you get to 3rd or 4th ? or just rolllll in 1st ? if it rols in first.. you got probs.. if it don't i think you have compression !!..

just some things to think about i guess.

good luck man !

**Tri-ZNate** · 06-14-2005, 06:44 PM

Originally Posted by bigredhead

When you say " No compression " .. have you put a pressure gauge on it yet ?

The kickers on the 85's are prone to failure from what i've read..... does the electric start still turn ? if it does.. open the side cover ( with engien IN frame ) and check the starter gears before you take the time to remove the motor.

if you put it in gear.. to bump start it... does it lock the rear wheels until you get to 3rd or 4th ? or just rolllll in 1st ? if it rols in first.. you got probs.. if it don't i think you have compression !!

I dont have a comp tester big enough for th hole. The one I borrowed is just a staight tube with a meter on the end.
I havent messed with it in a couple days due to how murdering my job is and how tired I am. If I remember correctly if it is in gear it wont roll.
But as for the starter gears, I think they are fine. I took the valve cover off hit the electric start and the valves move so I dont think the starter gears are broke.

**Dirtcrasher** · 06-14-2005, 07:50 PM

Valves can move but the piston won't if the connecting rod broke. This will be the 1st con rod I ever heard of snapping in an SX. There was a service bulletin about 1985 cranks snapping until Honda installed a new coil, affects certain part numbers. If you don't have time to yank the engine, first of all is there any compression at all - does it even remotely blow off your finger?? Second, put the flywheel on "T" and if you reach into the plug hole with something skinny you should feel the piston head up at Top Dead Center. Then rotate the crank 180 degrees (not 360) and you will be at Bottom Dead Center and whatever you put in there should now go in a couple inches deeper. That will tell you if Mr con rod and crank "seem" ok. But, even a slightly bent valve will prevent any compression from happening but the rockers will still move. That could have easily happened a few different ways.

**Tri-ZNate** · 06-15-2005, 06:32 PM

I have decided that I have too many SXs and need funding for a 350x so I'm gonna sell it.

**short4stuff** · 06-15-2005, 07:35 PM

Originally Posted by 250sxwheeliepop

I have decided that I have too many SXs and need funding for a 350x so I'm gonna sell it.

lol your giving up and havent even began? ...
A running SX will get you alot more than one that has a "blown" engine...

**Tri-ZNate** · 06-15-2005, 07:58 PM

I can get $600 outta it easily.

**bigredhead** · 06-15-2005, 10:15 PM

you can more out of it " easily " if the engine runs too !!!! a good shape SX gets minimum 1000 around here.

**phreakboy** · 07-05-2005, 03:26 PM

So Anyway, I got the 250sx off of 250sxwheeliepop, Right now I do not have a compression gauge, but I have popped the cover off and the valves are moving, piston is moving, So I am either thinking bent valves or rings. There appears to be no compression when you put you finger over the sparkplug hole. So I guess next step will be pulling the motor, is there anything special I should know about before I do? I really want to get this trike going asap so any help would be appreciated, and yea if it is in gear it will not roll.
phreakboy@comcast.net

**slothminx** · 07-05-2005, 03:41 PM

Originally Posted by phreakboy

So Anyway, I got the 250sx off of 250sxwheeliepop, Right now I do not have a compression gauge, but I have popped the cover off and the valves are moving, piston is moving, So I am either thinking bent valves or rings. There appears to be no compression when you put you finger over the sparkplug hole. So I guess next step will be pulling the motor, is there anything special I should know about before I do? I really want to get this trike going asap so any help would be appreciated, and yea if it is in gear it will not roll.
phreakboy@comcast.net

i would take the head off straight away and check out the piston if you cant feel any air coming from the plug hole i woould say a holed piston from a valve hitting it (maybe overrevved) or the rings have broken and its losing compression there. im very interested to know what has happened to this engine

will

**bigredhead** · 07-05-2005, 05:05 PM

when and if you remove the engine from the frame.. do NOT remove the angled part that hooks into the drive shaft on the motor side ( pumkin gear ? ) the shaft has washers that will fall into the tranny if you pull that puppy out.

other than that.. i highly suggest a manual.. it's an expense, but highly worth it !

**phreakboy** · 07-05-2005, 05:49 PM

ok now after messing with it more, when I have the sparkplug in and I crank it over, I have major air pressure coming out of the exhaust so I am assuming that something happened to the exhaust valve. ANYONE? Also is it possible to remove the head while the engine is in frame? I know that I can get to all of the bolts So I am hoping that it can be done without pulling the motor. If the valve is screwed up where is a good place to get new ones and any idea on price?

**Tri-ZNate** · 07-05-2005, 05:59 PM

If you can get to all the bolts I'd take the head off and leave the engine in. I didnt think you could get to all the bolts though.

**Tri-ZNate** · 07-07-2005, 09:57 PM

Were you able to make any progress?

**phreakboy** · 07-08-2005, 02:20 AM

THe only thing I got done so far was to get the top part of the head off to where I can see the cam, but I guess I have to take the side cover off to get the timing chain off so hopefully tomorrow I will do that.

**Dirtcrasher** · 07-08-2005, 06:27 PM

Originally Posted by phreakboy

THe only thing I got done so far was to get the top part of the head off to where I can see the cam, but I guess I have to take the side cover off to get the timing chain off so hopefully tomorrow I will do that.

Take the 2 10mm bolts out of the cam and then the 2 8MM bolts out of the cam chain tensioner bolted on the front of the cylinder itself. It's tricky but the cam can come out then. Tie a wire around the chain or it falls in the case and then you WILL have to pull the cover. The cylinder and head do come off in the frame but the dowel pins must be slid down from where the sit or they won't allow the head to come off.

Valves are like 30$ a pop, I buy OEM but hear Vesrah is just as good.

If you aren't reading and following a manual then your asking for more trouble.....

Thread: Need help and Advice on pulling an SX motor out of its frame.

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