Compression is low and motor using oil? : V-Twin Forum: Harley Davidson Forums

FlyingGasCan · 07-04-2009, 11:44 AM

I'm in the middle of a 5000 mile trip and and the new motor has now sucked a quart through in 1500 miles as I'm headed down the California Coast. Stopped in at a dealership and they checked compression and it showed 185 front and 175 rear when it should be well over 200 at sea level?

Hoping to do a leak down when I get to a preferred shop that I hope to visit and see what's up with the low compression. Hoping it's valve seals over the rings being the issue but lost for an explanation. Engines running strong and maps been altered for sea level so time will tell now. Noticed the pistons are now making a bit of a racket on morning starts when it's cold and they quieten up as soon as they get some heat in them.

Hope this mofo stays together for another week as I'm a long ways from home with the lower coast and the desert yet to come on the lower loop. Hey Steve...got any heads and jugs in stock? lol

wfolarry · 07-04-2009, 12:50 PM

The leakdown test will tell but it sounds like the rings are done. Hope it works out for you. What kind of oil are you running? [just curious]

Bamadan · 07-04-2009, 05:24 PM

Valve seats is a possibility for the lost comp, but does not explain the 1500 mile quart of oil loss. lower comp and oil loss points in another direction. just my thoughts of course.

Mo-Dog · 07-04-2009, 09:49 PM

Is your oil really black?...caused by gasoline contamination because of rings not sealed...where your blow-by test will show air leaking into the case. If you had the crank installed in the engine for you when you did the timken work then have the crank alignment checked by another shop for true center alignment in the engine case...don't ask me why...

TXCHOP · 07-05-2009, 11:18 AM

Sorry to hear Graeme...

Keep us posted and hope you get it fixed quick, but it does sound like WFO is right on..

HDWRENCH · 07-06-2009, 11:39 AM

Well if you run into too much trouble try and limp it into here. Yes we got stock stuff for you LOL

arealinvestor · 07-06-2009, 12:48 PM

Wow, this is not good!!!!

syco · 07-06-2009, 12:52 PM

You may have one of the SE out of round set of cylinders..Maybe time to bore to clean them up with some new pistons.

firehog383 · 07-06-2009, 02:37 PM

Mine were out of round and I had to have them bored .10 over. My good deal on S/E jugs were not as good once I had to pay to make em right.

C-Cat · 07-06-2009, 04:39 PM

sucks that you going to have to get back in the engine, hopefully it's an easy, inexpensive fix. good luck, and you're taking the engine issues a lot better than most!

FlyingGasCan · 07-07-2009, 10:57 AM

Quote:

Originally Posted by C-Cat

sucks that you going to have to get back in the engine, hopefully it's an easy, inexpensive fix. good luck, and you're taking the engine issues a lot better than most!

lol @ that one!

I was running Torco as per an R&R suggestion but changed the oil at Eureka HD and went back to my old preference of Red Line. It's not sucking anymore oil through which is good and it's still running strong as we are headed back on the homeward leg of the trip. I kept an oil sample and no it's not black.

I change oil about every 1500 miles and have done so since I built the motor. It now has about 6500 miles on the build and yes it could be the out of round cylinders. If so, I'll bore them to .010 and try it again.

Was going to stop in on ya Steve but it took more time to run down the coast than we thought, so we cut short at Frisco and are now up in Tahoe. From here we have a few rides to complete and that will take us home in a few more days. Bike is still running strong so I'll ride it home unless further issues develop. Still managed to do a couple long smokie burnouts in front of Dudley Perkins in Frisco before we left and it still makes lot's of power. (even as it pegs the rev limiter) lol

G.

FlyingGasCan · 07-14-2009, 03:27 PM

Bike made it home on Saturday and used 3/4 of a quart on the next couple thousand miles. Now that I'm back to work and trying to catch up on my paperwork, I hope to find some time to dive into things this weekend.

Funny how it went from 200ccp when dynoing the build 4 weeks ago to 185F/175R while riding down in CA. Thinking those rings are toast and hoping not to find anything else of contibuting significance. In either case, I better get on it as Sturgis is only 17 days away. lol

SLPER · 07-14-2009, 03:34 PM

Quote:

Originally Posted by FlyingGasCan

Bike made it home on Saturday and used 3/4 of a quart on the next couple thousand miles. Now that I'm back to work and trying to catch up on my paperwork, I hope to find some time to dive into things this weekend.

Funny how it went from 200ccp when dynoing the build 4 weeks ago to 185F/175R while riding down in CA. Thinking those rings are toast and hoping not to find anything else of contibuting significance. In either case, I better get on it as Sturgis is only 17 days away. lol

Good to hear you made it with out having to rip into it...Hopefully, just a set of 0.010+ pistons, bore, and back together..

Cheers!

PS Where's the video man!

FlyingGasCan · 07-14-2009, 04:49 PM

Might be the seals with that much oil use cause it wasn't smokin at all on the way home. In any case, headin off to the shop tomorrow to check it out and do a leak down. Should be fixed up for next week and at the worst it'll be a bore and a new set of slugs.

All is good as it can still rip it up as seen here doing a burnout in front of Dudley Perkins in Frisco. Cool freakin dealership it was! Here's a few pics from their shop!

LoneEagle964 · 07-14-2009, 05:39 PM

something just caught my eye your sig says 200 ccp@4500' and you say it dropped in frisco to about 175 that may be right as frisco is at or about sea level so you had about a 4000'-4500' elevation change may want to think that over also .

LoneEagle