Honda HRB536c HXE mower - Starting Problems and 'Hunts' when running

[snoopster]

I wonder if anyone can help me get this mower fixed.

Problem 1 It will not start unless fuel or carburettor cleaner is squirted through the carburettor intake. Once this is done the mower starts first 'pull', but once stopped it will not start again unless carb cleaner used again!

Fuel tanks has been rinsed out and had no dirt at all. Fuel hoses have been changed for new honda hoses. Fuel shutoff is working fine. I believe fuel is not being provided by the carburettor through the jet(s). I have had the carburettor off and cleaned the most obvious jet and removed a whole load of yellow waxy junk. I have blown out all other 'accessible' airways with carb cleaner. I do not know this carb well and so would appreciate some advice on any other jets or areas on the carb I should focus on with more thorough cleaning based upon the symptoms. Carb is a KEI HIN BB 62A C ME07.

Problem 2. When it is running it 'hunts'. Ie it cannot hold steady rpm but oscillates from high to low rpm continuously irrespective of idle speed. The only way of eliminating this is to use my finger as a 'damper' on the governor arm. A great solution but may be difficult to keep this up while cutting the grass ;-)

I am guessing this problem is fuel mixture. Turning the fuel mixture screw over 2 turns anti clockwise seemed to make no difference at all to the problem. New carb gaskets have been fitted but this made no difference and spraying carb cleaner on the outside of the carb whilst running made no difference to engine behaviour, so i do not believe we have gaskets leaks.

Other items addressed include - new spark plug which made no difference.

I still suspect the carburettor. Can anyone advise?

 

[Briana]

Welcome to LawnWorld!

We moved your thread to the Small Engine & Mower Repair forum.

 

[robert@honda]

I still suspect the carburettor. Can anyone advise?

Probably is an issue with the carburetor, perhaps some decayed fuel has turned to slime and is blocking a jet or nozzle.

A new carburetor is often inexpensive and faster/easier to simply replace vs. trying to properly and completely clean an old one.

Your model number indicates a non-USA model...where are you located? I can try and help you locate a dealer who can get you a replacement carburetor. I'd also suggest replacing the gaskets at the same time.

On the back of the mower deck is the serial number, in the form of "MXXX-1234567" so share that and I can see what I can find for you.

 

[snoopster]

Well, I guess everyone must be busy cutting their lawns.

Problem solved, previous owner had obviously been playing with the carburettor and had failed to replace the 'emulsion' tube. I thought it was strange that it was missing but could not believe anyone could forget to replace it as it is such a large component. Anyway New emulsion tube costs ｣23, new carburettor costs ｣40. New carburettor it was, now fitted mower starts first pull and engine speed is now constant.

Problem solved.

 

[snoopster]

Probably is an issue with the carburetor, perhaps some decayed fuel has turned to slime and is blocking a jet or nozzle.

A new carburetor is often inexpensive and faster/easier to simply replace vs. trying to properly and completely clean an old one.

Your model number indicates a non-USA model...where are you located? I can try and help you locate a dealer who can get you a replacement carburetor. I'd also suggest replacing the gaskets at the same time.

On the back of the mower deck is the serial number, in the form of "MXXX-1234567" so share that and I can see what I can find for you.

Robert

Thank you for your response and your offer for help, I have just seen it now. Yes it was the carburettor and as you advised a new carburettor and gaskets have been sourced and fitted.

Now the lawn is cut, I can see I now need to sort the blade brake clutch. (The blade takes a long time to reach speed and stalls easily on relatively short grass) Do you know if Honda do clutch 'kits' where all consumable components are provided together (similar to cars) or does one have to order each clutch component separately? If the latter do you know which are the common clutch components that need changing? It is a UK model HRB536c HXE

 

[robert@honda]

...I can see I now need to sort the blade brake clutch. (The blade takes a long time to reach speed and stalls easily on relatively short grass) Do you know if Honda do clutch 'kits' where all consumable components are provided together (similar to cars) or does one have to order each clutch component separately? If the latter do you know which are the common clutch components that need changing? It is a UK model HRB536c HXE

There is no clutch kit, just individual parts, as least that is the case for USA models and parts distributed in the USA.

So, this is a non-USA model, but you and the mower are actually in the US, correct?

The HRB536 was built in the same factory as its USA cousin, the HRB216, and I would guess the blade brake clutch parts are identical. That said, I have zero access to official documents for the HRB536, so can't say for absolute the parts and the same for both models. Also, there were two different styles of blade brake clutch designs used on the HRB216, and maybe on the HRB536 too.

Finally, it may be a worn clutch, or the symptoms could be due to a worn, stretched, or out-of-adjustment cable as well. I'd check it first, and replace/adjust as needed. If that checks out, you need to disassemble the clutch and measure the lining thickness to confirm it is worn or not before replacement. A paper shop manual is invaluable for this level of service; but, again, the USA version of the document will be somewhat different than the European one. You can get a USA shop manual from Honda via eBay or Amazon:

Honda Power Equipment Shop Manuals on eBay
Honda Power Equipment Shop Manuals on Amazon

 

[snoopster]

There is no clutch kit, just individual parts, as least that is the case for USA models and parts distributed in the USA.

So, this is a non-USA model, but you and the mower are actually in the US, correct?

The HRB536 was built in the same factory as its USA cousin, the HRB216, and I would guess the blade brake clutch parts are identical. That said, I have zero access to official documents for the HRB536, so can't say for absolute the parts and the same for both models. Also, there were two different styles of blade brake clutch designs used on the HRB216, and maybe on the HRB536 too.

Finally, it may be a worn clutch, or the symptoms could be due to a worn, stretched, or out-of-adjustment cable as well. I'd check it first, and replace/adjust as needed. If that checks out, you need to disassemble the clutch and measure the lining thickness to confirm it is worn or not before replacement. A paper shop manual is invaluable for this level of service; but, again, the USA version of the document will be somewhat different than the European one. You can get a USA shop manual from Honda via eBay or Amazon:

Honda Power Equipment Shop Manuals on eBay
Honda Power Equipment Shop Manuals on Amazon

This is a UK model, grazing in the UK on UK grass ;-)

Clutch - I have adjusted the BBC cable with no joy, so have dismantled the clutch to find that there less than 0.5mm of friction lining left. I am not sure what they are shipped from the factory with but i am expecting at least 3-5mm. So shall be ordering a new friction plate (75160-VE1-R4O).

Manuals - In the UK most companies do not issue service manuals in an attempt to leave you with no option but to use their dealer network, who then take maximum advantage of you. The US, though some may dispute it, are actually far more customer focussed. Honda UK is no exception whose website will only issue you with Owner manuals, NOT service manuals. Best i have found so far after much internet trawling for this model, is excerpts from service manuals for specific tasks such as transmission gearbox strip down and rebuild. By the time I have located a comprehensive service manual for this machine I could have probably finished the job. I do agree, life would be much easier with one!

 

[Phil G]

Hi snoopster, looks like most of your issues have, thankfully, been resolved.
From my experience of repairing Honda's, their blade brake clutch is not a fast acting clutch. The instructions advise engaging smoothly and quickly.

It is not uncommon on all Honda BBC's to have a tendency to stall as the engine load engages. Compared to other engines Honda's are lower revving (2800rpm). With a number of hours on the engine it's not going to produce the quoted power output.

If the mower's on the grass when engaging the BBC tilt it backwards to raise the front wheels slightly, then it won't be trying to cut the grass whilst engaging, also make sure the blade is always sharp and balanced.

Good luck, Phil

 

[Phil G]

Hi snoopster, looks like most of your issues have, thankfully, been resolved.
From my experience of repairing Honda's, their blade brake clutch is not a fast acting clutch. The instructions advise engaging smoothly and quickly.

It is not uncommon on all Honda BBC's to have a tendency to stall as the engine load engages. Compared to other engines Honda's are lower revving (2800rpm). With a number of hours on the engine it's not going to produce the quoted power output.

If the mower's on the grass when engaging the BBC tilt it backwards to raise the front wheels slightly, then it won't be trying to cut the grass whilst engaging, also make sure the blade is always sharp and balanced.

Good luck, Phil