Notice: Use of undefined constant viewnopostmembers1 - assumed 'viewnopostmembers1' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant viewnopostmembers2 - assumed 'viewnopostmembers2' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant viewnopostmembers3 - assumed 'viewnopostmembers3' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant viewnopostmembers4 - assumed 'viewnopostmembers4' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant viewnopostmembers5 - assumed 'viewnopostmembers5' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_0 - assumed 'pml_0' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_1 - assumed 'pml_1' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_2 - assumed 'pml_2' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_3 - assumed 'pml_3' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_4 - assumed 'pml_4' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_5 - assumed 'pml_5' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_6 - assumed 'pml_6' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_7 - assumed 'pml_7' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_8 - assumed 'pml_8' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_8_5 - assumed 'pml_8_5' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_9 - assumed 'pml_9' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_10 - assumed 'pml_10' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_11 - assumed 'pml_11' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_12 - assumed 'pml_12' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant pml_13 - assumed 'pml_13' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Undefined variable: cgi in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Undefined variable: ClickLogTime in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Undefined variable: ClickLogTime in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant new_some - assumed 'new_some' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Undefined index: new_some in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant new_none - assumed 'new_none' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Undefined index: new_none in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/english.lng on line 2

Notice: Use of undefined constant moderators - assumed 'moderators' in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Load.php on line 455

Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355
Print Page oldski-doosleds' Vintage Ski-Doo Message Board
    oldski-doosleds Message Board => Help Desk (Only) => Message started by: rkalter on July 31, 2017, 08:10:59 PM
	

Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355

Notice: Undefined variable: mc_data in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Load.php on line 69

Title: 76 340RV problems
Post by: rkalter on July 31, 2017, 08:10:59 PM

The first step is admitting you need help lol. Hellllp.
I just had my cylinders machined to 40 over. The ring gap was at 0.45mm. Specs say from 0.2 mm to 0.5mm so the machinist did a poor job in my opinion but would this alone yield a compression value of only 100 psi or is there something else wrong. What compression numbers should I be seeing on this engine? It won't even fire up. I've got good clean strong spark. I've checked the timing on rotary valve and stator twice. I do have a 1976 Skidoo RV340 shop manual that I'm following religiously. Lost and confused.
Ray


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: Green and Gold on August 1, 2017, 08:02:45 PM

Hopefully your shop had the new pistons in hand and fit the bores to them using the min piston to wall clearance number. Some of the shops I’ve visited don’t do things that way, they bore without referencing actual piston size.(i.e, if a 63mm is the stock bore, 4th oversize would be taken out 1.0mm to 64.00mm) This can certainly introduce error; I’ve had aftermarket pistons that were supposed to be the same diameter vary in size. Things get worse if the same machine shop bores in inches and your piston was forged/cast to metric measurement; .040in converts to 1.016mm
So what’s your piston to cylinder wall clearance? That would be the clearance I'd be most concerned about. Hopefully you have a good set of T gauges and micrometer available....
To the issue at hand, I’ve had low initial compression on fresh top end jobs; it sometimes takes afew minutes of running to seat the rings into the freshly honed cylinder walls and then compression climbs. Somewhere between 95 and 100 PSI (measured on my comp gauge, readings can vary a lot between gauges) is what it takes for my F/As to start. Assume you’ve added fuel directly to cylinders in your attempts to start? You could also try adding some 2 stroke oil directly to each cylinder (thru the plug hole) and then a few drops of gas to see if you can get your initial start that way. New plugs would be a good idea too.
Good luck.


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: rkalter on August 8, 2017, 06:56:55 PM

Hello Green and Gold. The shop was supplied with the new pistons and rings along with my shop manual for the exact specs required with the page book marked. The boxes were never opened and the rings were still wrapped in their packaging when I got it all back. They never measured anything except the bore.
I do not have the tools to measure either the bore or the piston for you. But I can tell you it slops from side to side quite a bit with the piston rings on!! And that the ring end gap was at the end of spec 0.45mm for specs 0.2 - 0.5mm.
I have added fuel directly in spark plug holes too. No difference. I am using new plugs.
I found a bad spot in wiring harness that may have been causing some issue. Couple wires rubbed bare. I went through all the wires and fixed the one bare spot I found. Now it bucks and farts but still won't start. I have slowly moved the stator plate from one side to the other and back in small increments with no change in firing. Just bucks two or three times. Just a quick pop pop pop as I pull it over and then nothing.


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: Bones on August 9, 2017, 11:07:28 AM

Try switching your spark wires to opposite sides to what you have now.
Bones


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: mikesskidoo on August 9, 2017, 12:23:48 PM

I had very very similar symptoms an my issue as it turned out was lack of compression..... seemed like it would "run" as you were pulling it over... but would not quite run on its own.. found my compression leak and fixed...fired right up. best of luck


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: rkalter on August 9, 2017, 03:09:27 PM

[quote author=Bones link=board=1;threadid=24438;start=0#msg145006 date=1502302048]
Try switching your spark wires to opposite sides to what you have now.
Bones
[/quote]hi Bones. I forgot to mention but I did try swapping the spark plug wires back and forth as well as the trigger wires. Didn't work. When I switched the triggers I lost the attempt to fire so I switched back and it began popping and farting again.


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: rkalter on August 9, 2017, 03:10:30 PM

[quote author=mikesskidoo link=board=1;threadid=24438;start=0#msg145007 date=1502306628]
I had very very similar symptoms an my issue as it turned out was lack of compression..... seemed like it would "run" as you were pulling it over... but would not quite run on its own.. found my compression leak and fixed...fired right up. best of luck
[/quote]where was your loss of compression??? Maybe I have a similar problem. Thx.


Notice: Undefined index: todayMod in /home/boardnation/users.boardnation.com/public_html/shared/1_4_2/Sources/Subs.php on line 355


Title: Re:76 340RV problems
Post by: mikesskidoo on August 10, 2017, 05:41:01 AM

mine was due to poor machining on the cylinder heads, pressure was leaking down the holes the cylinder studs run through, but because it wasn't leaking out where I could see it, it took a long time to find the problem, which is my fault 100%, I stupidly ASSUMED that.."this is a newly rebuilt engine it cant be the compression?!!" ::) ::)



oldski-doosleds' Vintage Ski-Doo Message Board
Get your Ad Free Message Board at Boardnation!   © 2013 Boardnation  Web hosting by Nubis