Topic: Mismatched lower fork tubes?

[swellguy]

Hello Colleagues,
I've been working on my 73 cb750 cafe project for awhile now. Finally got some parts from Benji and have some free time to work on the bike.
One of the pieces I ordered were the stainless fork covers:



I disassembled the forks and tried some dry fitting of the pieces. I noticed that there was no way the lower covers were going to fit onto my fork lowers because the diameter of Benji's lowers was less than the outside upper lip on the top of my lowers. We emailed several times and he said that they should just slip on because they had been test fit with a set of 73 forks at his factory.

Obviously mine were different, not stock, but everything else seemed stock since the original fork boots had fit, etc. so I took the decision to mill down the outside lip of my fork lowers so Benji's covers would slip on, which they now do. Meanwhile I had ordered new oil seals - to fit a 73 - without thinking more could be at issue. I tried installing them into the top of the fork lowers and they just dropped in and are about 1.5mm smaller than what would actually fit snug.

So my question is, does anybody happen to know what Honda lower forks I might have? Again, the outside diameter of the top edge seems bigger than a stock 73 and stock Honda oil seals are about 1.5mm too small to fit snugly in the lowers. I am still running the stock 35mm upper tubes.

If this is of any help, the only identifying marks on the lowers are the numbers 341 stamped on both of them:



Any and all help is greatly appreciated.

[wrenchmuch]

The forks shown in this link are early types .
http://forums.sohc4.net/index.php?topic=74442.msg828155#msg828155
 Notice the hole pattern where the brake caliper attaches . My K1 looks like this . I also have a k4 and it has the same pattern of holes as your pic shows . I can't speak to a difference in diameter between the two but I do know the seals are different .
http://www.cmsnl.com/honda-cb750-four-k3-us_model481/partslist/F++08.html
Cmsnl shows the K3 as having the later type of fork lower , like yours in the pic . You might have seals from a earlier type . Going to the garage to measure .
Mike

[wrenchmuch]

I used a divider and rule so measurements are approximate (can't find vernier caliper ) . 50 mm for the K1 and 48 mm for the K4 measured from just above where the circlip is . My k4 forks were NOS purchased in 1998 and might not be what was supplied with a K4 .

[swellguy]

Hey thanks a lot. Looks like I have earlier, say K1 lowers since milled off about 2mm od material to get Benji's covers to fit. I'll do some digging through some if the Honda parts catalogs I've got here somewhere and maybe the 341 stamp might confirm it. If there are different seals for these years, I'll order the other set. Maybe even one of my local dealers have a set.

I used a divider and rule so measurements are approximate (can't find vernier caliper ) . 50 mm for the K1 and 48 mm for the K4 measured from just above where the circlip is . My k4 forks were NOS purchased in 1998 and might not be what was supplied with a K4 .

[wrenchmuch]

The bolt pattern for the caliper mount looks like 73 or later though  . Maybe someone with more knowledge than me will have a answer .

[swellguy]

I'm not really sure which fork lowers they are but I did a double check and I can see that the dealer sold me the wrong part. The K3, K4 & K5 catalog shows a number of part numbers for for oil seals but they all have a 35x11x48 dimension. The parts #s on the bags I have don't match the catalog numbers and my oil seals are 46.6mm wide. I'll just take them back. Hate when this happens.
Thanks for all the help.
Kerry

[swellguy]

More of a rant now . . .
Called the dealership and asked them to do a search with the new part #s. As with a lot of original part #s they are often superseded with newer ones and oil seals to fit K3 forks are no different. The guy said he had none in stock, none in Vancouver but a pair in Calgary. "Come on down to the store and we'll order them up (prepay)".
I get why dealers want to be prepaid and have no trouble doing so but this particular shop insists that someone physically come down to effect the transaction. I explain that I had already been down before and that they had sold me the wrong part. Apparently I had been vague in my request for "front fork oil seals to fit a 1973 cb750". The clerk had recalled how he had to go through microfiche records, then go to an uncustomary location within the store to retrieve them. He then commented "I told you they looked like the right ones" but that he didn't guarantee that they would fit.
I explained that I'd never have bought parts if there was some question in his mind that they weren't the right ones in the first place.
"Well come on down to the store and we'll exchange them when we order the new ones."
I suggest that there is no necessity make two more trips when one will be sufficient - once the correct parts have arrived - and for which I'm happy to give the fellow my VISA card number at that moment.
"Sorry, you have to come down to the store."
"I've already been down to the store, you have already acknowledged I was there when you sold me the wrong part. I'm not taking another half hour out of my life to do this."
"Sorry, but you'll have to come down to order the correct parts you need."
#$%* them, SG Power located on Hillside Avenue in Victoria BC.
BTW called the other, two in stock, awaiting my pick up later today. Thank you Action Motorcycles.