why so slow

[frankb]

Hi. Just picked up a 1968 520. Thing runs great, but only does about 45mph. I know it has 67hp, but my u521 has the same engine and will easily do 65mph. wondering what it could be. Just had the carb fixed and it's better, but I have no idea what else it could be. maybe the rear end? Any advice or mods would be greatly apprciated.

[wayno]

Do you only go 45 because it sounds like your revving too high and you don't want to rev it any higher, or are you floored and it just will not go any faster?

 

[bilzbobaggins]

Where are the pics of the u521?!?!?!?!?!!

 

 

[frankb]

can't seem to attach it to this, so i made it my profile pic

 

[datzenmike]

On 12/16/2019 at 5:12 PM, frankb said:

Hi. Just picked up a 1968 520. Thing runs great, but only does about 45mph. I know it has 67hp, but my u521 has the same engine and will easily do 65mph. wondering what it could be. Just had the carb fixed and it's better, but I have no idea what else it could be. maybe the rear end? Any advice or mods would be greatly apprciated.

 

Can't be the rear end Nissan used the same one in the L521.

 

Check the fuel is at the line on the glass front of the carb.

Replace the fuel filter. Cost under $5 and no harm done if this isn't it.

Check the valve lash.

Check the timing.

 

To post a picture you will have to get a picture hosting account such as imgur. (but there are many others) Do NOT use Photobucket.... ever. Download and save your pictures there. Later go there and copy the picture information and bring it to Ratsun and paste it into the text.  

[difrangia]

Check cylinder compression

 

Insure gas pedal is pulling carbuerator to full throttle

Edited December 23, 2019 by difrangia

[frankb]

Thanks guys. I'll check it all!!! Now, to find a wiper motor that fits. Mine is toast. Any suggestions on a replacement?

 

[wayno]

Is this wiper motor you need for your 520?

Edited January 14, 2020 by wayno

[frankb]

wayno, I need a wiper motor. Did you try and post a pic?

 

[wayno]

Basically I was asking if you need one for your 520 as I expect that one to be LHD, the U521 could be either LHD or RHD.
As I recall the 520 has only one speed, does the wiper switch only come out one click?

No I didn't try posting a photo.

[frankb]

ah, i see. Yes, it is my 520 LHD. It only comes out one click. I've been searching for a couple of days trying to find one, with no luck. I'm not sure if there is a bolt on replacement that fits the 4 prong junction

[wayno]

OK, so the plug has 4 wires.

How do you know the wiper motor is bad and it is not the switch that is bad, you sure the plug is making all the connections?

I ask because these trucks are getting old and wiring gets crusty, so again how do you know it is the motor that is bad.

I will look at my stash of wiper motors.

Edited January 14, 2020 by wayno

[frankb]

Well, when I pull the switch, the blades raise halfway and then they just freeze. That leads me to believe that the connections are being made to fire the motor, but then it seizes. I'm new to working on cars, so I could be wrong for sure. It just seems to me that it is the motor. Thanks so much!!!!! All of the similar motors I see have 5 prongs and different connectors

[wayno]

OK, first you need to disconnect the wiper assembly(transmission) from the wiper motor and see if you can move it with your hand without it dragging/seizing, if it moves freely then it is likely the wiper motor but I suspect it is one or both the pivots seizing from sitting too long without use.

First see if you can move them by hand disconnected from the wiper motor, if they don't move easily then try a lubricant of some kind, do not force them and break the wiper assembly as finding one of those will likely not be easy or cheap.

[wayno]

On 12/17/2019 at 3:53 PM, bilzbobaggins said:

Where are the pics of the u521?!?!?!?!?!!

 

 

 

Here is a photo of his U521.

[bilzbobaggins]

29 minutes ago, wayno said:

 

Here is a photo of his U521.

 

I got blisters on my fingers.

[Crashtd420]

2 hours ago, wayno said:

 

Here is a photo of his U521.

That is just awesome.....

[frankb]

Thanks for the love, guys. Her name is Carmen , and I'm toying with the idea of bringing her stateside. If anyone is SERIOUSLY interested, send me a private message. Thanks

[Stoffregen Motorsports]

Where is it now? I see you're profile says you're in Georgia.

 

My grandparents had a place on St Simons Island. Coastal Georgia is so beautiful.

[banzai510(hainz)]

choke flap blocking the air?  distributor off a tooth?

Edited February 24, 2020 by banzai510(hainz)

[frankb]

stoffgregen - The u521 is in Costa Rica. The 520 is in Savannah.

 

banzai - Thanks! I'll check those

[banzai510(hainz)]

I see a kid install a weber on a 510 and he didn't hook up the electric choke. I forgot if it was a org manual carb or not. Most J motors I assume are manual as the are older vehicle

 

2nd 510 I cked out the distributor wasn't pointing at TDC when I lined it up. But a timing light would catch this as oe could not get to 0-25 degs with the light. Believed he was to far advance(im guessing) reset dist and got more HP

 

[banzai510(hainz)]

also see if the 2ndary on the carb opens up if a stock carb.

 

if stock carb I rev it up then put my hand over the main barrel side and see if the vacuum opens up the 2ndary carb barrel if no then it might e stuck