81 185s compression

[jarodbro]

I just replaced the rings and top end gaskets on my 81 185s. It used to have a really loud tick and it blew tons of white smoke. After replacing the rings and gaskets, I can only get about 61 lbs of compression. I have gone back through the cam chain/ cam shaft and valve cover assembly 5 times thinking i may have had the chain off by a few links. I am pretty sure that i didnt have the rings lined up. I dont know where i should look next. Are the lobes on the cam supposed to be up or down on the cam when
assembling?

[drivetime]

Did you check the compression before you changed everything?

May need to bore it out and put in a slighlty bigger piston?

[muthey]

if you look at the manual it shows the pin for the pulse generator pointing west north on the shaft on reassembly, if that doesn't work then you need to to replace your piston rings and have it bored

[tri again]

I just replaced the rings and top end gaskets on my 81 185s. It used to have a really loud tick and it blew tons of white smoke. After replacing the rings and gaskets, I can only get about 61 lbs of compression. I have gone back through the cam chain/ cam shaft and valve cover assembly 5 times thinking i may have had the chain off by a few links. I am pretty sure that i didnt have the rings lined up. I dont know where i should look next. Are the lobes on the cam supposed to be up or down on the cam when
assembling?

wow. Sounds like you did it right so far.
Everyone who's rebuilt an engine started with their first one, right?

You should be able to find a free manual in the 'world class help' section.

I've heard the valves should be adjusted with the cam lobes Up in most all 4 stroke engines. (and down on occasion)
as far as setting the cam to TDC? I've heard the crank and cam TDC marks are not always easy to see.

Not sure it matters but the crank and cam TDC marks come around at different rates.
In other words, the crank TDC should come around twice for every cam TDC. unless I got it backwards.
and you want the spark to hit on the correct TDC (actually a few degrees before TDC)

You'll get it.

[jarodbro]

When i had the top end apart, the cylinder looked and felt fine. I did not check compression before the i ripped it down. I have the shop manual and i followed every step in there. I was able to find the T on the flywheel that is to be lined while the cam sprocket mark should be at the 12 o'clock position. I am not sure if i am looking at the right mark on the sprocket tho. the manual says there should be a 0 to indicate my mark. Mine only has a very small circle that doesnt really look like a zero. do i need to have the exhaust hooked up and the carb to check my compression? I really want to be able to fix this thing on my own and not bring it to a shop. thanks so much for the help so far. does any one know of any videos of a top end rebuild or assembly? Thanks!!

[tri again]

When i had the top end apart, the cylinder looked and felt fine. I did not check compression before the i ripped it down. I have the shop manual and i followed every step in there. I was able to find the T on the flywheel that is to be lined while the cam sprocket mark should be at the 12 o'clock position. I am not sure if i am looking at the right mark on the sprocket tho. the manual says there should be a 0 to indicate my mark. Mine only has a very small circle that doesnt really look like a zero. do i need to have the exhaust hooked up and the carb to check my compression? I really want to be able to fix this thing on my own and not bring it to a shop. thanks so much for the help so far. does any one know of any videos of a top end rebuild or assembly? Thanks!!

You're doing good so far.
Engine marks are often punched in with a hammer and marking tool so not always clear.
Connecting rods are famous for that because they are all sized individually.
and marked by a monkey in the machine shop.

Nope, no need for exhaust or carb for compression test. Just do NOT run it with the exhaust off.
It will kill your ears and warp your exhaust valve.

The only internal thing would be to hone the cylinder so the new rings have something fresh to seat to
( and staggered ring end gaps) but
I'd leave it together and check valve adjustment and cam timing first.
There are other ways to get rings to seat so worry about that later.

A plastic straw in the sparkplug hole to confirm TDC on the piston and
cam lobes pointing UP and your marks should be more obvious.
Both Cam lobes up means you are at the top of the compression stroke, ready to fire.

Someone adjust the valves on my 87 br with the cam lobes pointing down and it sounded like a jackhammer
and had almost no compression.

Hope fully your fix is super easy.

Pls keep us posted.

Try a search right on youtube.
Someone's surely done it.
This cam mark alignment stuff comes up almost too often so don't take it too personally.
Maybe you can also try the search key on here for 'cam timing' or similar words too.

[falcody]

This may sound stupid, but does the 185s have a decompression lever on it?

[shortline10]

61lbs is not enough compression for you to be able to pull start the motor , If you didnt hone the cylinder then that is prob your issue . You can try and bump start it or have someone pull you behind another atv and once it starts you might get lucky and the rings might seat . best is to pull it back apart and do it right .

[jarodbro]

the cylinder is fine. it is not scratched at all. i know that it wont start with the compresion i have on it now. i have followed the steps in the shop manual. i think i am just going to bring it in somewhere. Thanks for all the help so far.