The pain and frustration of getting the tappet clearance right.

[Old Boy]

As I took my Himmi of the road for the winter, 21 model, as I live near the sea and the road service throws salt around like it’s out of fashion. I have always done my own Serviceing so I decided to check the valve gap. So off with the tank and then the tappet covers. After a bit of wriggling the wiring out of the way (cable tied it up out of the way) I found the tappet gap setting from the forum and checking with YouTubers. The figures I got are as follows INLET .08-.10 mm and EXHAUST .23-.24mm. the in i set to .09 and the exhaust to .10 mm. Great I thought even though there was very little room to do the job. Tank on pipes connected plugs in. Started the bike up and when it came off the choke the engine was hunting just slightly, I let it run for a few minutes to see if it would settle it down but it wouldn’t. So after much swearing I took the tank off and let the engine cool overnight.
Next morning went through the whole procedure again this time I couldn’t get the inlet gap right. A great deal of swearing later I eventually got it to loosely set at .08 mm. Tank on everything connected up started up and running but still with a bit of hunting. To say the least I was not happy.

I am going to have to get a new set of feeler gauges as my set (brand new) hasn’t got a 9mm have to use a 5mm and 4mm together this causes one of the feelers to bend. not To sure though.

Has anyone got any tips before I get into a right hissy fit.
The engine was running fine tho a little fast on idle but that would settle down after a few mins to about 1100 rpm. I’m going into the house for a cuppa to calm down.

 

[Turbofurball]

Hopefully there's a typo in there 'cause you said you set the exhaust to 0.10 for a range of 0.23 to 0.24 ...

Anyway, it's normal to have to combine feelers, but you shouldn't need to bend them much - checking the gap is an exercise in humility and grace for everyone, but it gets easier with practice. If your bike hasn't been used properly for months the hunting could be anything (condensation in the petrol, ethanol has started to separate in the tank, damp air filter, some deposit on the plug contacts has decided the evolve into a new lifeform, etc etc), best thing is if the engine revs cleanly then take it out for a solid Italian tune-up (thrash it a bit), get some fresh petrol in it, and see if it's still having trouble after everythings had a good blow-out.

 

[Old Boy]

Thanks for that, I think the fuel might be the problem I had forgotten about the ethanol and I will drain the tank ( fuel for the Seagull outboard) spark plug is ok and I will check the air filter. A night in the airing cupboard should do the trick. The bike has been in the garage since october last. Thanks for the tips, ride safe.

ps it was a typo I had had enough by then.

 

[Turbofurball]

You're welcome anyone that's ever worked on a bike has lost their patience with it at some point! (and may have gone on a murderous rampage if Chinese fairings were involved)

Remember the fresh petrol will take a while to work through the injector, and a bit of healthy wide-open-throttle will really clear it out. I've only ever needed injector cleaner with old diesels, but that's also an option.

 

[Harleyboy]

If storing in future for any length of time, drain fuel where possible or possible look at additive. If additive used they do recommend tank kept full I assume to reduce condensation/moisture build up on cold metal.
Tappets as said can be frustrating but agree perseverance prevails; for info I do/check mine every 6mths or 1800-2000 miles just my preference.

 

[grymsr]

If storing in future for any length of time, drain fuel where possible or possible look at additive. If additive used they do recommend tank kept full I assume to reduce condensation/moisture build up on cold metal.
Tappets as said can be frustrating but agree perseverance prevails; for info I do/check mine every 6mths or 1800-2000 miles just my preference.

I always throw in stabil and some injector cleaner at the end of riding season. Works for far.

 

[Bikebit]

I think you need to get a 650 as a second bike and practice setting valves on that. Much easier. Then when you are feeling good about yourself, set the valves on the Himi. That will giving you enough courage to try to put the rocker cover back on 650, and make you appreciate the Himi that much more!

 

[OldGuy]

I would not use feelers. From what I've seen (and experienced), the dishing of the valve stem prevents feelers from getting accurate clearances. I have a 2020 Himmie with less than 1200 miles that I'm hopping up, and the exhaust valve has a very obvious dip in the end of the stem. I'm replacing the valves with good ones from Hitchcock's.

I think you're better off using a dial indicator or as @Roy Gavin has suggested, just the turns on the adjuster (run it down to contact with the valve stem, than back it off xxth of a turn). Roy has posted the info before about threads/mm and how to adjust valves that way.
OG