Carb Question 1976 70hp and 1989 60hp

[jim_in_day]

Well, I'm back working on my possessed 70hp RUDE. I just got it installed on a new hull and all the wiring done, time to get this puppy working right! I asked this question last year and DHadley and company indicated it should work. I just want to clarify questions in my mind before i make the switch. I ended up with 3 carbs off an 89 60hp with electric primer and want to switch the carbs out with my 70hp old worn out carbs. I can't seem to find the cu. on the 89 60hp. 88 60hp was 49.7 cu and the 90 60hp was 56.2 cu. Will the difference in cubes matter to the carbs? The 76 70hp is 49.7 cu so that's why i was wondering. I have been playing with it in the yard, and it is back to its possesed ways. Yes i have done compression spark and fuel tests. I used to think i was loosing spark when it got hot, but we got it to drop today, and I have 3 very hot sparks. It acts like it floods when it gets hot. almost like vacumn is pulling the choke butterflies closed. It finally starts in a cloud of smoke until it clears and settles down. It will then run until i turn it off and let it sit 10 min. Then is is really difficult to start again. That's why I think i need to change the carbs.

 

[F_R]

Re: Carb Question 1976 70hp and 1989 60hp

The '89 60hp is 56.1 cu in. (920cc). I'm not going to even try to get involved in the swap question. Except to ask why in the world do you think the carbs are worn out?? Never saw a worn out carb on a motor that wasn't itself worn out 3 times over.

 

[jim_in_day]

Re: Carb Question 1976 70hp and 1989 60hp

Well, I've replaced every electrical part on the motor, When it acts up it still has 3 good strong sparks and the carbs have been gone thru with a fine tooth comb. It acts like it is flooding while it is cooling down. When i can get it to start, it smokes just like its a very rich mixture. Also while it is running, occasionally it acts like it's loading up and drops a cylinder (like it gets overly rich in one carb). We have had 1 other 3 cyl. give us similiar problems that required a carb replacement to fix. I am at a loss to explain what is happening, but since i have these carbs, i figure that what the heck, i still have all the old stuff, if it doesn't work i can switch back. I also like the idea of updating to a primer system instead of a choke.

 

[jim_in_day]

Re: Carb Question 1976 70hp and 1989 60hp

ok now i'm scr###d !!!! I was putting the top carb on from the 60hp and the timing pointer interfered with the nipple for the primer and broke it off. OUCH. anyone know how to replace that nipple? It looks easy enough to drive out, but then where do i get a replacement part? I think that any johnnyrude carb that uses a primer instead of a choke would be a cannidate for a donor nipple.

edit---- I went back and looked and DHADLEY said that the swap should work, so I am working under that assumption. The throat on the back of the 60hp carb is smaller than the 70hp carb by about 1/4 in, and the jet is a 46d instead of a 52, but it fits (except the nipple on the top carb around the timing pointer).

 

[Kevin W]

Re: Carb Question 1976 70hp and 1989 60hp

It sounds like you need a complete carb cleaning and carb kits for the original carbs.
It would most likely be cheaper and easier to rebuild them than try to replace them with another carb that does not fit perfectly.
And guess what!
you may need to rebuild the new ones too.

And when i say complete i mean removing welch plug and cleaning out all passages spotless.

.02$

 

[jim_in_day]

Re: Carb Question 1976 70hp and 1989 60hp

Kevin, the old carbs were kitted an spit polished, didn't help.
and yes, the new ones will need kitting also. I repaired the primer nipple (yankee ingenuity) and got it running(kind of) today, but it's still not right. My partner and I are trying to get it adjusted correctly so it will stay running at something under 1500 rpm