87" 70HP Rude running on one cylinder

[rude87]

Have beed trouble shooting my 87" 70HP 3 cyl Rude. Have good spark, good compression, new wires and plugs. Have one cylinder firing. When I switch the carb from the good cylinder to another then that cylinder fires. Figure I have two bad carbs. Thoroughly cleaned both bad carbs with no luck. Figure that the carb bowl pin and seat may be bad and is flooding cylinders? I am ordering rebuild kits, but would like to know if anyone else has seen this problem?

 

[jtexas]

Re: 87" 70HP Rude running on one cylinder

unless "thoroughly cleaned" includes "disassembled and soaked overnight in carb cleaner" then they might not be cleaned as thoroughly as you thought.

just my opinion, doing 2 of 3 carbs is a waste of time - just getting the airbox & carbs off the engine is more than half the job......

you can test the float valves by blowing through the intake (best take carb off engine and drain the bowl first ) - held upside down no air should pass, held rightside up should be very little resistance.

 

[clemsonfor]

Re: 87" 70HP Rude running on one cylinder

yes had it happen to my 60hp 3 cyl. was loosing a cyl somethimes then it went to all the time, turns out that the float got unadjusted somehow and was flooding my bottom cyl. It would start great cold b/c of the extra fuel but would quickly drop it again. Cleaned and adjusted the carb and fixed the problem!

-Nate

 

[rude87]

Re: 87" 70HP Rude running on one cylinder

JTEXAS
Dissasembled carbs and blew cleaner through all openings. Used small diameter wire to go through openings as well. I did not soak overnight. Did notice that carb that works has a all steel needle and the other two have a rubber tip. Maybe these are worn. I tried to bend the floats down to force a better seal to no avail. I have new carb kits on the way and I will pull the carbs again and soak them while I wait.
Thanks for the reply.

 

[rude87]

Re: 87" 70HP Rude running on one cylinder

Nate,
It's good to know I am not alone. Have new carb kits comming and I hope to be on the water before summer ends.

David

 

[rude87]

Re: 87" 70HP Rude running on one cylinder

jtexas,

I am writing this with the taste of gas & oil still on my breath. I tried the float test you suggested and I could move air through the intakes of the two bad carbs when upside down. I could also move air on the good carb, but it took alot more lung power. I have rebuild kits comming for all 3 carbs and hope that will solve my problem.
Thanks again for the tip.
David