Honda 2.3hp problem

Steve65 said:
Hi Dennis,
Sorry I couldn't be of any help at the minute. I think you said you put a new plug in, if not change the plug.
Check the colour of the old plug, if it's black it's running rich, You may be able to adjust the carb by the tick over mixture with the screw...turn it inwards to lean the mixture.
If it's still rich the carb will need rejetting
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Thanks Steve - yes I changed the plug and the old plug was indeed black when I took it out. However, a potential confounding factor there is that a friend had put the engine in the lazarette on the wrong side with the shaft a bit higher than the head. When I got it home I pulled the plug and then pulled the engine starter cord a few times. No oil came out of the plug hole, and it ran when the new plug was inserted. I've just tried tried turning the mixture screw fully in and it didn't solve the issue. I've got a new carb coming, and will fit that when it arrives to see if that solves the problem. If it does, I'll look to send the old carb off to you at some point for inspection and repair as always good to have a spare. If new carb doesn't solve the issue I guess I'll give in and wait until your work dies down ;)
 
DennisF said:
Thanks Steve - yes I changed the plug and the old plug was indeed black when I took it out. However, a potential confounding factor there is that a friend had put the engine in the lazarette on the wrong side with the shaft a bit higher than the head. When I got it home I pulled the plug and then pulled the engine starter cord a few times. No oil came out of the plug hole, and it ran when the new plug was inserted. I've just tried tried turning the mixture screw fully in and it didn't solve the issue. I've got a new carb coming, and will fit that when it arrives to see if that solves the problem. If it does, I'll look to send the old carb off to you at some point for inspection and repair as always good to have a spare. If new carb doesn't solve the issue I guess I'll give in and wait until your work dies down ;)
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Is it a Chinese carb?
They aren't the best, I have never got one to run correctly. Other Chinese carbs are ok apart from these copies
Hopefully you may be lucky
 
Steve65 said:
Is it a Chinese carb?
They aren't the best, I have never got one to run correctly. Other Chinese carbs are ok apart from these copies
Hopefully you may be lucky
Click to expand...
It's advertised as OEM, but with eBay until it arrives you can never be sure. Fingers crossed....
 
I'm all for cheaper alternatives for getting engines back running. Used lots and lots of copied carbs with great success, but the Honda copies I have had weren't successful, which is very frustrating
 
Steve65 said:
I'm all for cheaper alternatives for getting engines back running. Used lots and lots of copied carbs with great success, but the Honda copies I have had weren't successful, which is very frustrating
Click to expand...

So is there a 'brand' of Chinese copy that would typically be good for a 3.5 2T Tohatsu in your experience?
 
Mark-1 said:
So is there a 'brand' of Chinese copy that would typically be good for a 3.5 2T Tohatsu in your experience?
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To be honest,I only usually buy 4 stroke carbs, 90 per cent of engines I work on nowadays are 4 stroke, but I'm sure you can buy Tohatsu 3.5 2t copy carbs.
Have a look on Ali express, I know you can buy piston and rings for this engine on there for a tenth of the price of genuine
 
Steve65 said:
Steve65 said:
Float isn't adjustable
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you are correct. So that leaves us with valve not shutting properly, float not floating properly for whatever reason, mixture screw not set BUT why that now? What we do know is it’s running rich, the question is why? We all try to diagnose at distance but inevitably the answer is sometimes OIE. The trick is guessing what has gone on to cause the issue.
Click to expand...
 
Steve65 said:
Hi Dennis,
Sorry I couldn't be of any help at the minute. I think you said you put a new plug in, if not change the plug.
Check the colour of the old plug, if it's black it's running rich, You may be able to adjust the carb by the tick over mixture with the screw...turn it inwards to lean the mixture.
If it's still rich the carb will need rejetting
Click to expand...
We’ve established its running rich by the fact that shutting off the fuel eventually causes the revs to rise as it runs out of fuel.
Functioning for a long time carbs don’t need rejetting!
 
Beneteau381 said:
We’ve established its running rich by the fact that shutting off the fuel eventually causes the revs to rise as it runs out of fuel.
Functioning for a long time carbs don’t need rejetting!
Click to expand...
If the float isn't sealing you have fuel leaking from the vent holes at the façe of the carb and also the top vent tube
 
Steve65 said:
If the float isn't sealing you have fuel leaking from the vent holes at the façe of the carb and also the top vent tube
Click to expand...
Functioning carbs for a long while do not need rejetting, cleaned jets and carbs often need rejetting especially when pilot jets are nylon
 
Beneteau381 said:
We’ve established its running rich by the fact that shutting off the fuel eventually causes the revs to rise as it runs out of fuel.
Click to expand...

I'm not sure that's conclusive. Engines often speed up with they run lean, that doesn't mean they were running rich in the first place.
 
As promised, an update. After swapping the carb for a replacement the symptoms were exactly the same. Choke out causes the engine to falter and then die. I’ve already replaced the spark plug, cleaned the fuel tank and the filter was clear. After discussing with Steve65 and sending him a video, it seems the next step is to replace the ignition coil, when I can find one. These things are sent to try us….
 
DennisF said:
As promised, an update. After swapping the carb for a replacement the symptoms were exactly the same. Choke out causes the engine to falter and then die. I’ve already replaced the spark plug, cleaned the fuel tank and the filter was clear. After discussing with Steve65 and sending him a video, it seems the next step is to replace the ignition coil, when I can find one. These things are sent to try us….
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Is there something you can do to make life easier for the existing coil as a diagnostic measure? Narrowing the plug gap on a brand new plug and seeing if it solves it, for instance?
 
Mark-1 said:
Is there something you can do to make life easier for the existing coil as a diagnostic measure? Narrowing the plug gap on a brand new plug and seeing if it solves it, for instance?
Click to expand...
I took off the coil today to clean the mounting points and reset the gap in case it made a difference. It didn’t, and whilst doing that the new plug was black when I pulled it. Also, it still revs up nicely just before it runs out of fuel, which seems odd if it’s the coil at fault. Before I spring £100 on a new coil, just in case both the old carb and the new one (which is a Chinese copy) are over jetted I’ve taken the old carb to Steve65 to see if he has time at some point to put it on a running engine and just double check it isn’t the carb before spending more money.
 
Eureka! The engine is fixed! Because the new plug was black (indicating running rich, in keeping with choke out making running worse) in desperation I took off the air intake guide that bolts to the carb and flushed it through quite a few times. On the fourth or fifth time some debris came out and after flushing through again until clear I then dried and remounted it. Now running normally, thank the Lord. No idea how the debris got in there but happy that the issue is now sorted. Thanks for everyone’s suggestions along the way, especially Steve65 who has also provided help and guidance offline 👍🏻
 
DennisF said:
Eureka! The engine is fixed! Because the new plug was black (indicating running rich, in keeping with choke out making running worse) in desperation I took off the air intake guide that bolts to the carb and flushed it through quite a few times. On the fourth or fifth time some debris came out and after flushing through again until clear I then dried and remounted it. Now running normally, thank the Lord. No idea how the debris got in there but happy that the issue is now sorted. Thanks for everyone’s suggestions along the way, especially Steve65 who has also provided help and guidance offline 👍🏻
Click to expand...

I knew it was that all along. :)

Seriously, brilliant outcome and thanks for bothering to share the solution. 🎉
 
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