With all due respect MrMarty51-
Most of the people that have been helping have responded to both threads.

ALSO- My second thread started with 1 particular question that I had in particular- that I wanted to post in a different place because I really wanted a quick straight forward answer from as many people just on that ONE question, IF YOU WOULD HAVE READ FROM THE TOP. The thread ended up getting off track with people not just answering my speciffic question. NOT WHAT I INTENDED

If this REALLY disgusts you- SO be it.

 

tv4fish-
Thanks, I will try that tnight if I have time- just got called back into work.
Gotta go.

Thanks Again

 

Hey guys- Sorry I havn't kept u all up to date- havn't had time to work on it for a while. Plan on doin some work on it next week sometime. I will keep you all posted.
Thanks
Kelly

 

tv4fish-
I had put the atv on hold for a while and am gonna get back at it this week.

Anyways- Tnight I finally checked the piston ring end gaps. I called Polaris and the correct end gap clearance for my motor is .009-.018

After checking my gaps with the feelers like you had told me, I found my reading to be more like .020-.022

Think I may have found my problem. Bore was too big for the rings. This may have been my fault- I may have told him to bore it out at the wrong specs.

Do you think I had good compression at first when doing a simple thumb check was because the oil I used to lubricate the new top end kept a seal under less internal pressure. But once I installed the spark plug or compression tester, thus creating greater internal pressure, it caused blowby( air to exscape around the rings) due to too big of ring end gap? Causing such a great loss in top end pressure- way below 100psi - more like 40.

If this is the case- What are my option?
Will I have to get it rebored and honed to PROPER specs and get whole new piston and rings?

Thanks
Kelly

 

Hello-
Let me know if anyone is still following this

So about 2 weeks ago I took my cylinder and new piston (.040 over) to have it rebored and honed. Then I waited for the new top end kit to install it.

I was excited to finally get everything back together and give it another go around. Took my time putting it all back together so I didn't mess anything up, even put some copper permatex on the head gasket (oem style) to reassure a had a good seal up top. I will admit, my last gaskit I had the head off a few times so it had been retourqed a few times, not this time though.

Finally, got it all together and still no start. I had SPARK, FUEL, but Compression was still low . For days I thougt and thought, giving myself headaches, what could be wrong? I rebuilt the whole motor and I was sure there was no leaks in the lower end- crank seals, case half. Top end should have been solid as well.

I looked in through the intake to look at the piston and rings- and thought that the one ring I could see, the ring end gap seemed a little wide. So, I took the top end off again and took the rings off the piston. I used the top of the piston to slide each ring down the cylinder to remeasure seperately. Low and behold- I found my ring end gap at .026-.027 Are you kidding me!!! They should be .009-.018. The cylinder was supposed to be bored .002 over. When I got the cylinder and piston back from the same guy, I asked what the ring end gap came out to be. He told me .015-.016 range.

I am pretty upset, kinda sad at the same time. My whole goal was to get this thing up and going for a ice fishing trip for my dad and I over my vacation so he did not have to walk as much. I havn't been able to ice fish with him as much in the past few years due to blood clots in his legs, so I had been goin by myself alot the past few years. I really should have remeassured everything myself right away when I got it back, but I trusted he measued everything right. RRRRRRRRRRRRRRRRRRR!

Any thoughts????

Kelly

 

I'm getting kind of lost on this deal. First you say:
Then you say:

Was the thing bored 40 over? If so, was it done correctly?
Was the piston to bore clearance supposted to be .002? If so, is it?

Was it machined with too much clearence or is the ring set the wrong size?

If the former, you need to take it back to the machinest and say: DUDE!!! check this out...........what are YOU going to do about it?

If the latter, get the correct ring set, install them and go have fun.

Something else is kinda weird to me. Even with a ring gap this big it should get some fairly good compression numbers.
I have had two strokes run as low as 40psi. I bet I could get a four stroke to run at 50 or 60 psi.

My best advice I can give you is SLOW DOWN!!! It is not a race to put an engine together correctly. Measure everything and write it down and log it. If you find something fishy (like the ring deal) STOP and call the person you got the rings from and discuss the problem.

Answer some of the above questions and I will see if I can help you out.

I just have a bad feeling that once you get the ring bore piston deal straightned out that the thing still won't run for some reason.

BTW Merry Christmas and let us know so we can get you out ice fishing again!!!!

 

The piston cylinder clearance was to be bored over .002 on the new 40 over piston size.

I think it was machined with too much clearance. I am goin to take it back in to him and have him remeasure it in front of me. All I have measured is ring gap. To correct spec for ring gap on this motor is .009-.018. I am getting .026-.027. I am getting compression and some sign of life out of the motor with gas and spark igniiting. Sorry I don't have any numbers for ya on compression- left the comp gage at home both time I went to work on it this week. Just not quite enough to get it going. A ring gap that big is pretty far off from spec. The rings are straight from the piston kit marked 100 on the ring, meaning 1.00mm over bore as is the 40 over bore piston= 1.00mm over

I think it will make a huge difference if I had my ring gap clearance down within spec. Really I have been taking my time on this motor. Been working on it for more than a few months. Really, I think I have everything set right, beside thinking it was michined to big. I could rebuild the whole thing in a day easy if I had all the parts and tools to bore and hone it myself. Time will tell.

Thanks for your help
Merry X-mas

Kelly

 

Sounds like you need to have a chat with your machinist then. I wish you good luck with that deal. Every time I came across a deal like this it went something like this:

Hey, you bored the jug too big. " Awww it's ok, don't worry about it". A little more clearance is ok.

Anyway I hope you get it straighten out and get it running. Merry Christmas to you too.

 

yah, I've heard others on this site with the same response. but, if you don't get what you paid for it's not right. Sucks havin to have the talk, but it's gotta be done. He had everything there and the correct measuements. You just gotta stand your ground, but have compossure at the same time.

 

Things to check.
Don't proceed with anything, until you do a correct compression test.
Any chance your exhaust is completely blocked?
Any chance your piston is in backwards (markings need to point forward)?
Any chance you carb is completely closed?
You said you had carb problems, Are you flooding this out and washing the cylinder DRY?
.002 piston to cylinder wall clearence should be OK
Are your rings marked .040 oversize to match your .040 over pistion?
If you don't have locating pins in your piston grooves, are you staggering the ring end gaps?
Have you changed to a properly gapped NEW SPARK PLUG, or are you using a foulded out one?
Are you sufficiently oiling up your rings and cylinder wall prior to starting so it will seal?

Seeing you have messed with just about everything in this engine, Compression, Fuel delivery, and Proper spark and timeing are all now Suspect Problems. We would all like to help you here, but it may be time to pay a professional to fire this thing up for you.

Hope you get it solved.