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4323 Carb to Manifold Bolt

PostPosted: Wed Sep 02, 2020 7:03 am
by bill pedalino
The parts book lists the two 4323 carburetor mounting bolts as 1" in length. However, using the three insulators, 2 thin washers and the upper cable bracket, the 1" length is too short by about 3/8" to achieve adequate thread purchase into the aluminum DC Linkert body. Unfortunately, I cant find a 3/8'16 x 1-3/8" or 1-1/2" C.P. bolt in Harley's bolt listing for this purpose. I'm currently using a modified, Cad-plated stock bolt. This raises Three questions; 1. Has anyone experienced this problem? 2. If so, were you able to find an OEM bolt for this application? 3. Were these bolts Parkerized or Cad plated?
Thanks,
Bill Pedalino

Re: 4323 Carb to Manifold Bolt

PostPosted: Wed Sep 02, 2020 7:43 am
by wz507
I know nothing of your specific application, but regarding the fastener you seek Old Dude has a 3/8-16 x 1-3/8” CP1038 bolt. You’d have to call about the finish, but they often have them in both cad and park. Colony offers the same bolt but with a plain head in cad and park.

Re: 4323 Carb to Manifold Bolt

PostPosted: Wed Sep 02, 2020 8:24 am
by bill pedalino
Thanks for the reply. I spoke with Bart awhile back and he didn't have that size - I guess that's changed. I'm having the bike virtually judged in a couple of weeks, so I'll order several in each finish to make sure I'm covered by that time.

Re: 4323 Carb to Manifold Bolt

PostPosted: Wed Sep 02, 2020 5:02 pm
by strong56KH
I have never had a problem using the 1" 4323. Three gaskets are used, two thin paper gaskets sandwich a slightly thicker manifold gasket (insulator). If you are using 3 insulators, that may be your problem.

Re: 4323 Carb to Manifold Bolt

PostPosted: Thu Sep 03, 2020 7:08 am
by bill pedalino
Actually, unlike the distributor-equipped XLH, the XLCH takes 3 insulator blocks, P/N 27412-57. This is because the carburetor has to be spaced further out on the CH in order for the bottom edge of the air cleaner cover to clear the magneto cap.

I've noticed that there are some variations in how far the magneto sits toward the outboard side of the motor when properly timed. I attribute this to very slight variations in where the magneto drive ring is pressed onto the No. 2 cam gear. But the 3 insulator blocks are correct. I then surmised that the OEM blocks might have been a slightly thinner that those that I had, so I found some OEM insulator blocks in sealed Harley packaging. Upon measuring, I noted that the thickness was consistent with those that I had. I installed them, obviously with the same result.

Maybe Harley felt that the shallow thread purchase was acceptable, but I see it as a potential problem, especially on the top location where the cable stay bracket is installed and especially in an aluminum body.

Re: 4323 Carb to Manifold Bolt

PostPosted: Thu Sep 03, 2020 11:48 am
by Rubone
Bill,
The portion of the body (throttle body) of the DC carb is cast iron, not aluminum.

Re: 4323 Carb to Manifold Bolt

PostPosted: Thu Sep 03, 2020 11:54 am
by dlxl66elxl
The bolt length as shown in the parts book for the 3 insulation gaskets is too short. Over time we have discovered quite a few errors in the parts books and I believe this is one of them.

Re: 4323 Carb to Manifold Bolt

PostPosted: Thu Sep 03, 2020 12:51 pm
by bill pedalino
Yes - Thank you for the correction; I forgot that the base is cast Iron - better than aluminum, but still a soft metal. However, cast iron or aluminum, a 3-thread purchase isn't enough.

Re: 4323 Carb to Manifold Bolt

PostPosted: Thu Sep 03, 2020 12:56 pm
by bill pedalino
At this point, if Bart doesn't have the correct C.P. bolt length (or longer), I have a bottle of highly concentrated sulfuric acid. It will strip the cad plating off of my current bolts in seconds. Then it's a dip in the parkerizing pot....

Thanks to all for your input.

Re: 4323 Carb to Manifold Bolt

PostPosted: Fri Sep 04, 2020 4:57 pm
by bill pedalino
After speaking with Bart at Old Dude I learned that the correct 1-3/8" bolt for this application is P/N/ 4354B. Also, as per Dave C. they should be Parkerized for early Sportsters. I bought the last 2 that Bart had in Parkerized and two more in Cad to be stripped and re-finished. If you need them, please let him know in advance if case he has to replenish his Parkerized stock.