Jump to content

jr50 cuts off soon a choke down

Recommended Posts

Hi i came across a 1993 jr50 for a decent price so i got it just for my kid to play around on starts right up runs pretty good solid bike only issues soon as you push the choke down it dies out and with out the choke down it goes alot slower.. tried giving the carb a good cleaning no luck it seems like there are no air leaks anywhere any ideas please help thanks not to familiar with these bike thanks 

Share this post


Link to post
Share on other sites

Ok let's think about this for a minute, what's the purpose of a choke? Well it does just what the word says, it "ckokes" meaning it restricts air flow. A carb needs a prescribed amount of a fuel/air mixture at each throttle position. So if it runs properly with the choke on (air restricted) it would stand to reason it is either getting too much air per the amount of fuel being delivered or there's not enough fuel being delivered for the amount of air... make sense? That means that there is an air leak (you've stated you don't believe that to be an issue) or there is a restriction in the fuel delivery. If the cause is the latter that means you have a clogged jet (jets) or an issue with the float, fuel needle, gas line, petcock or some combination of those.

 

From my experience the most frequent cause is clogged jets n carb passageways. In order to clean a carb thoroughly the jets need to be removed. Also remove the floats and fuel needle. Once removed spray them and all passageways with carb cleaner and most importantly blow them and passageways out with compressed air. If you don't compressed blow air thru them you are wasting your time. Jets also tend to have holes drilled in the side of them that also need to be cleaned, sometimes a small diameter wire is required. After cleaning make sure you can see light thru the inner diameter.

 

I can't tell you how many times I've cleaned carbs for friends who believe they had already cleaned them to find out they really haven't and that turned out to be the issue. If it's been sitting for some time it is invariably the carb that is the issue.

 

 

 

Sent from my SM-G930P using ThumperTalk mobile app

 

 

 

 

 

 

 

 

 

 

Share this post


Link to post
Share on other sites

well i clean the crap out of the carb and adjusted the float now it runs with the choke off still alittle boggy at times on my way to get a new plug iam running a cooler plug now bp6hs because it seems to run pretty hot i will try the recommended bp4hs and see what happens

Share this post


Link to post
Share on other sites

it may be different i have sold that 1 and it was a 1993 and was clearly marked choke on was up 

i solved the problem by cleaning the crap out of the carb adjusting the float and putting a new plug in 

thanks for your input

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×