Johnson 20hp runs only on choke!

[Russell Huish]

Hello wondering if anyone can answer this problem? The 20 hp 1969 Johnson I rebuilt was running fine till last outing. Now it will start easy but only with choke out. I can push choke in but it will die after a few seconds unless choke pulled out again. This engine has had all electrics replaced, impellor etc and I have tried two carbs, same problem with both and three fuel pumps that I have as spares. Still does the same thing tho, help would be appreciated, ta, Russell.

 

[kbait]

Re: Johnson 20hp runs only on choke!

Confirm carb jets/passages are clear w/canned 'duster' air and straw. Replace high/low needle packing (I use tru-value #47 o-rings). Confirm fresh fuel and no air in any hose fitting from tank to carb. If unsure about fuel, hook up fresh tank and use the bulb to flush out before connecting line from pump to carb. Make sure you install the gasket around that brass tube when you put the bowl back on. Should go..

 

[tashasdaddy]

Re: Johnson 20hp runs only on choke!

contaminated carb, time to clean and rebuild. see the TOP SECRET FILE.

 

[Russell Huish]

Re: Johnson 20hp runs only on choke!

Thanks for your replies, I will order a carb rebuild kit this week. Cleaned out carb but tried to get away without rebuild. Should have known better.

 

[Russell Huish]

Re: Johnson 20hp runs only on choke!

Cleaned out carb again and rebuild done. If honest still expected some probs but apart from slight tendency to judder at low revs ( i think it needs a good blast as not used for so long) it now runs fine, thanks, Russell.