Iridium failure? (top end carnage) top end time...

[85RZwade]

Aside from the pain in Mark's ass and the new hole in his wallet, this has been a great thread. Great reading, made me think and I may have even learned a thing or two.

[m in sc]

NO PAIN REALLY im used to it being into these things this long. Pistons are a consumable service part.... sometimes. well, that service is accelerated a bit. However, keep in mind i could be completely wrong on my diagnosis. time will tell. Wont be the 1st time.

why its not running yet:
Yesterday I put in a heavier duty relay (actually went to an 85A continuous duty solenoid, marine style) for the galaxie as monday the twin fans were running intermittently on the way home and i'm not going to blow up my motor due to a 30 amp relay. so that rewire ate up last night, tonight is dinner with my brother but after that will prob dip into the garage and finish bolting the pipes on. 

[teazer]

I must have been asleep in class, but I just noticed that TZ water pump on the clutch cover.  How did you mount and drive that?

On the R5 side cover I fitted one in place of the oil pump, but it sits on an adapter plate.  That was a common conversion for karts back before my time. I had a pile of ex kart motors and bits a few years ago and that's where mine came from.

[m in sc]

adapter plate as well. used the 'stock' tz drive and rd oil pump gear.

heres the paint curing  last year in the sun when i resealed the clutch cover (had developed a slight seep)

[teazer]

That's neat.  I cut down the side cover a little further than yours and I think I used the RD oil pump gear IIRC.

[m in sc]

I mistyped  oil pump gear as well

[m in sc]

so back together all good. however.. im wondering if indeed the rotor DID indeed slip.  heres why: the washers under the m7 were a bit concave in. now, the witness marks i had put on seemed to still line up but when i verified it with my dial gauge and poiter ( i have a committed one out of aluminum i made). 

If it was out it wasnt much. i pulled the rotor, and machined a 3mm 316ss washer for the drum. bought some slightly longer m7 bolts and heated the rotor, used  adash of sleeving loctite and ran it down.


jetting still at the richer settings, with a 280 main seems to like it ok. it does run -really- well but i didnt take it far had stuff to do today. But it may have been my dumbass the whole time. not sure. its seemed like it was maybe ony 1-2 degrees out if anything. 

[1976RD400C]

You would think for the price of those ignition kits that they would include a nice hard thick washer. I noticed how the washer concaved on my HPI and installed 2 grade 8 washers.

[rodneya]

You would think for the price of those ignition kits that they would include a nice hard thick washer. I noticed how the washer concaved on my HPI and installed 2 grade 8 washers.

The thicker washer and bolt kit is only $12 at Economy

[rodneya]

got 'oh shit' fan wired in on radiator as well. temp switch in head will kick on at 195. (this is primarily for getting stuck in traffic situations). its a small spal fan but it moves a shit tone of air.

carbs on, jetting up to 280 to start.  still need to mount pipes and break in, will have to wait a day since i have family in town coming over for a dinner tonight.

How did the fan fit on your rad?
Its over 100 deg here at the moment (very un-Canadian) and my bike has been overheating so I fitted a fan from a GSXR that was in my parts bin.
Fits ok, but it is pretty wide and I had to move the rad forward about 2". Kinda loud as well but it does work.

[Clem710]

IIRC, a few years back, it was discovered that copycat/fake NGK iridiums were being being sold.  I presume, primarily online but there was a huge bad batch of vespa clutch bushings that were coming from reputable suppliers 5 or 6 years ago.

I find it incredible that this would be the problem here but it does follow the rule of "what did you F with last" method of troubleshooting:)

Glad to hear there was no physical damage to the rider, bikes can be fixed.  In fact, OP will likely just make it faster

[m in sc]

the plugs were legit, i never order them online, ever. however, 99% sure it was the rotor slipping. wild speculation got the better of me.

I do know john sells the thicker washer (and i would recommend it) . However, i bought this unit way before john started selling them. Im pretty sure its the 1st one in the US after FLA Steve found them online.  The one i have on the r5 has the upgraded washer. ;)