Problem with Compression or Timing on High Compression L20b causing pinging

[510SSS]

RacerX it's not that, I know enough about L series to have checked that many times over, So, I went down to the shop today and it would seem that the carbs that Wolf Creek Racing sold me as they were closing, because of the owner's recent passing were built hasily and the internal jets were not screwed in all the way, this caused a lean condition in cylinder number thee and a semi lean condition in the other cylinders, this is why it was pinging so badly under load, now I have to get my Mikuni's rebuilt again, even though I already paid a bunch of money to get em rebuilt, FML, oh well I forge ahead with the carb rebuild, thanks to all who gave advice it really helped me narrow down the problem, turns out it wasn't the timing, not the dizzy, nor the plugs, or even the oil pump tang, but rather a hastily rebuilt carburetor causing a lean condition in my cylinder due to being built improperly. :crying:

[KoHeartsGPA]

Well...I'm glad you didn't start buying stuff, as we were telling you from the beginig....needs tuning....always start with easiest options ;)

[510SSS]

Thanks for the kind words Ko, I'll keep you guys updated on what happens with Wolf Creek, should still be under warranty as far as I know, considering their mistake could have caused damage to my engines break in by causing fuel wash in my cylinders :devil: Hopefully they can hook me up and take them back and rebuild them the legit way, otherwise i'm gonna just send em back, and get some DCOE's instead, seems to be a lot more tuning info and jet availablity compared to the Solex/Mikunis :hmm:

[KoHeartsGPA]

Yes. You owe us oics! We don't forget!

[racerx]

Figuring out the problem is 1/2 of the solution. It seems like wolf creek owes you. The main thing is that your engine did not get damage.

[banzai510(hainz)]

not really much to rebuild on them. long as they dont leak and the accel pumps fine I cants see too much going wrong with them besideds dirt and the jetblocks backing out or the funnels inside go loose

 

The jets blocks may back out rebuilt or not. Mine back out all the time, then runs fine

[KoHeartsGPA]

Yup, they're very simple and basic.

[Stoffregen Motorsports]

Mikunis are so vastly superior to Webers, I would really try to keep them. Simpler to make jet changes, the accel pumps are better, venturis and aux venturis are easier to remove/replace, etc.

 

I have seen loose jet blocks cause damage to the threads in the carb body before, but if the threads are ok, tighten everything up and move on.

[racerx]

Out of curiosity can lock tight be used so that the don't come off.

[Colbino]

I had advanced distributors recurve mine. No pinging whatsoever; L20b, bored, domed pistons, U67, dual 45's.

[Doctor510]

Out of curiosity can lock tight be used so that the don't come off.

NO NO NO NO!  I found that some very fine mono-filament fishing line used as a thread lock (installed vertically) is best, I raced Pro Solo for 5 years with that and they never backed out.

[john510]

9 pages for pinging ? I bet i could have that thing running just fine in 30 minutes,assuming it doesnt have some major problems.

[KoHeartsGPA]

9 pages for pinging ? I bet i could have that thing running just fine in 30 minutes,assuming it doesnt have some major problems.

Well...not everyone has tuning knoledge.

[datzenmike]

Well...not everyone has spell check knoledge.

 

 

 

 

9 pages for pinging ? I bet i could have that thing running just fine in 30 minutes,assuming it doesnt have some major problems.

 

Well haven't heard if this is it either, yet.

[510SSS]

Well considering I'm just learming mechanical knowledge, I was not raised with my dad working on cars at all, I have learned all I could in the last 3 years, and this is my first datsun, but good for you that you're mr. insto fixit, I wish I had you're talent man, (not you're ego though..) Ok so I have my friend who has raced Datsun 510's for 30 years look over the main and pilot jets tomorrow and make sure everything is screwed in properly and re-jet if need be. Only then will I try to send in my Dizzy and have it re curved as a last resort, ya I hear Advanced Distributors does a good job, others have recommended them to me as well, but would you say they are better than Rebello? I don't really wanna have to send my Dizzy all the way to the east coast. Cool thx Doctor 510 for the trick with the micro filament fishing line, sounds like a good idea if they keep backing out as time goes on. Thanks again. :D

[john510]

Well...not everyone has tuning knoledge.

After 9 pages of advice anybody that read all this has tuning knowledge.

[KoHeartsGPA]

:fu: Mike :fu:

 

Ya missed a W so what.

 

:lol:

[Stoffregen Motorsports]

It's ironic. A word associated with cognition is misspelled. That's all.  It's ironic and a little bit funny.

 

(I just had to spell check "misspelled", so don't feel bad.)

[docbainey]

Wolfcreek racing sucked, ripped my budy off with some bogus rebuilt sht for his roadster, then he goes off an dies!

[Stoffregen Motorsports]

Dude, harsh...

[510SSS]

Ya I kinda feel like rather than really rebuilding the carbs completely it seemed as though they found a set that were in good condition, cleaned and polished them up a bit and just sent them out now that I look at them closer, damn I wish I had sent em back right when I got them, oh well, I guess I will have to fix them up myself, luckily they gave me a bag of replacement parts, time to bust out the Mikuni book's and learn to take these things apart. :confused: How about a motorcycle shop? they probably tune carbureted Mikuni bikes all the time, can't be that much different anyone ever try this? 

[KoHeartsGPA]

You don't need a mikuni book, Google is your friend and a great tool :thumbup:

[Stoffregen Motorsports]

Why do you want to tear them apart? Make sure the jets are all tight. Double check that the accell pumps are working and run it.

[Doctor510]

Ya I kinda feel like rather than really rebuilding the carbs completely it seemed as though they found a set that were in good condition, cleaned and polished them up a bit and just sent them out now that I look at them closer, damn I wish I had sent em back right when I got them, oh well, I guess I will have to fix them up myself, luckily they gave me a bag of replacement parts, time to bust out the Mikuni book's and learn to take these things apart. :confused: How about a motorcycle shop? they probably tune carbureted Mikuni bikes all the time, can't be that much different anyone ever try this? 

HUGE difference between the cycle carbs and the PHH,  get the book.  

[scooter]

Why do you want to tear them apart? Make sure the jets are all tight. Double check that the accell pumps are working and run it.

This. Stop fucking around. Its a datsun and you have to check everything once in a while cause shit vibrates loose.