Removing rear carb to get battery out, tips?

[TexasDreamer]

I'm about to change the battery in a 1991/92 Super Sprint, RHD. I can't see a way to get the battery out other than removing the rear carb. Any tips or tricks to getting the carb out? Can I simply (yeah, right) unbolt everything and pull it out? Do I need to buy new gaskets to go between the carb and the manifold or can I re-use whatever is there? Carb is Weber 40 DCOE 151.

[Kitcat]

My LHD 97 Super Sprint's battery was also under the carbs. But it was small enough that it could be wiggled out(barely), without removing the carbs or surrounding hoses, etc. Maybe look into replacing the current battery with something smaller and doesn't take as much effort to replace? My Cat used a smaller, tractor style battery, maybe 1/3 the size of a normal auto battery.

I know this doesn't solve your current dilemma tho.

[bball7754]

Can you go out the bottom?  You would have to jack up the front of the car, or even put it on 4 jack stands, but it seems like it would be doable.

[Anker]

I drop mine down to the floor instead of trying to lift it out.

[TheDingo8MyBaby]

Typically there is a small plate either made of metal or plastic with one (metal) or two o-rings (plastic) between the carbs and manifold. They're called soft mounts. They're also typically mounted using nylocks with thackery washers or soft rubber bushes.

 

As long as the o-rings are in good shape, you should be able to reuse them.

 

removing the carbs is very easy. Just make sure you don't spill the fuel out of the bowls. The tricky part is mounting them without over-tightening the mounts so they still flex. If you have the thackery washers, it's a good ideal to measure the distance between coils before disassembly so you can torque the nuts to get that same distance on the coils. You should also be prepared to re-sync the carbs. 

[Anker]

It is actually easier to remove the manifold with the carbs attached from the head. The carb to manifold nuts are very hard to get at and have to be torqued exactly right. All the manifold to head nuts can be easily accessed with a socket extension. Don't forget to partially drain the coolant! 

[TexasDreamer]

Good tips. I ordered the battery. Kitcat's comment pushed me over the edge to get a lithium battery. My previous thinking was to stay with PC680 because 1) it's more or less original (totally irrational, I know, but hey, the whole car is totally irrational) 2) fear of the unknown and 3) with this car I'm trying to resist the temptation to continuously "improve it" and be disciplined to "leave well enough alone". However, all that pales in comparison to getting the battery out. Just saw the pictures of a red 1992 with the battery right up top where my heater is. Right now I'm feeling like I would gladly give up the heater to turn this battery replacement into a ten minute job.

 

I'll try to get it out the bottom first and if that doesn't work, cross the that bridge when I get there. Will update the thread when I get it done but it may be awhile. The spring re-landscaping is taking precedence.

[Elise111]

A PC680 should easily slide out the bottom- that’s what I have under my carbs. 

[TexasDreamer]

Over the Memorial day weekend I swapped out the battery. No way was it coming out the bottom. The corner of the battery tray filled the gap between the tubing and the engine block. I thought about cutting off the corner of the battery tray but couldn't bring myself to do it. Following @Kitcat suggestion, I put in a smaller battery. The lithium is much smaller and lighter. Although I didn't check, I'm expecting it would squeak out the bottom. Pulling the carbs was not hard, but it did take a long time because I was very tentative. I also had to detach the ignition coil and the speedometer cable, but avoided taking out the steering shaft by 1/8 inch. Instead of just the rear carb, I pulled them as a pair because I could not get the accelerator cable bracket which tied them together loose. I was going to refresh the carbs while I had them out but my family gave me pressure to get the toy running for play time so I just put them back in. 

 

Amazing difference in the starting experience. I'm not sure how much is the old battery being very weak and how much to attribute to the new battery being lithium. However, it now spins fast and starts immediately. One thing to say about this car is that it always starts, even when the weak battery was barely turning it over. 

 

Now, I'm working on dialing in the carbs. I showed the YouTube video to the car but apparently the car wasn't paying attention. How to Balance & Tune Twin Weber DCOE Carburetors | Tech Tip 18 - YouTube First thing is the idle speed is too high, around 1200 RPM. I get there by screwing the rear carb idle speed screw all the way out and then setting the idle speed screw on the front carb so the air flow matches. Second thing is that the idle air mixture screw on the rear cylinder has no effect. I can close it down all the way and nothing happens. Next weekend I'll try again. in the meantime, I'm happy that the toy is fully drivable and that I that at least haven't made it worse in some noticeable way.