the -15 is vac advance can spec, not the centrifugal.
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| another pulsar dizzy https://www.ausmini.com/forums/viewtopic.php?f=2&t=24189 |
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| Author: | midlifeminicrisis [ Sun Oct 29, 2006 7:46 am ] |
| Post subject: | another pulsar dizzy |
Finally 2 weeks ago got modified pulsar dizzy D4R85 into my LS1275 - unmodified 1100 S block, cept for cooper head. This was done by an auto elecy who said they had a mini mechanic. Ii took it for a run up the central coast next day to see grlfrnd an found that i had lost all power when it came to going uphill, can't handle th load. This was so bad that it would lose rev's an backfire. Also noted at th time that the temp would go way way up into nasty zone. Checked th spark plugs an found that sparkies on #1 an #3 were cookin, melting ceramic. They were NGK BP5ES so replaced them an gapped to .040 also got new leads an put them on. So back it to th auto eleccy last sat an they had another go while i was sleepin aftr niteshift. I showed them th sparkies as well. Took it for another run to th coast th next day an same prob happened with th new plugs. After work yest bought BP6ES (gapped at .035) to thro in an went for a quick run to Menia to have a little go at those hills an again loss of power, backfiring an overheating. Also a little kickback has started to appear when cold starting. I've spent a lot of time perusing th wealth of knowledge here last nite an conclude the dizzy has too much advance. Right or Wrong??????? If this is the case then i gather i need to: A. firstly check the static timing (TDC, BTDC an ATDC) an then use a timing light - Which i don't have, so any cheapo one do from supercheep? B. secondly check th dizzies advance. So far i hope i'm on track. Another questn: wot nasties does an over advanced dizzy cause an how will i be able to check that these haven't occured? I know its late notice but if anyone is free today to assist, an teach a youngish ol fart for a slab or two...I gladly garner wot 's required an head on over. Drop me a pm or an email Tks John. PS: i have my reasons for not wanting to bo back to auto eleccy an shan't be sayin so. I'm also mechanically illiterate |
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| Author: | drmini in aust [ Sun Oct 29, 2006 7:53 am ] |
| Post subject: | |
Any cheapo strobe light will do, mine is just a cheapie. If it kicks back when starting, it sounds over-advanced to me. Most 85 dizzys have a 12* advance plate in, but I've seen one with a 15*. If it has the 12* one (gives 24* total in crank degrees) set the idle advance to 5*BTDC at idle, with the vac advance hose (if it has one) OFF. If it's got a 15* one set idle advance to TDC as above. |
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| Author: | midlifeminicrisis [ Sun Oct 29, 2006 7:56 am ] |
| Post subject: | |
thanx kev from memory it is a D4R85-15..I'll check soon. |
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| Author: | drmini in aust [ Sun Oct 29, 2006 7:57 am ] |
| Post subject: | |
the -15 is vac advance can spec, not the centrifugal.
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| Author: | midlifeminicrisis [ Sun Oct 29, 2006 6:00 pm ] |
| Post subject: | |
ok...itz about 99.9% now...i turned th dizzy about 1.5 -2 degress (max) anti clockwise....no timing marks on the harmonic balancer and as blind as i am i just couldn't see wot i was doin....but i can now power up a hill.... still would like to know wot happens if u run with too much advance? remember reading last nite a mention about burnt pistons????? wot does happen if u run with too much advance an how do u check if th nasty has happened?? Tks John |
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| Author: | drmini in aust [ Sun Oct 29, 2006 6:34 pm ] |
| Post subject: | |
Best way to set advance is find TDC. Mark the balancer and timing cover. Then put a mark `30* BTDC' before that TDC line (ie behind it) on the balancer. Paint with white paint. Then, rev the motor with the vac hose off until at max advance (~4000 rpm) the marks line up. 30* total advance is a good starting point for most roadgoing Mini engines. TOO MUCH advance can cause detonation (pinging), may give piston failure. Doesn't help engine bearings either. You are then firing it too soon before TDC, so it tries to slow the pistons down instead of just allowing for the pressure rise time.. |
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