Author [ES] [CA] [PL] [PT] [IT] [DE] [FR] [NL] [DK] [NO] [GR] [TR] Topic: Surprised by valve clearances out of spec again  (Read 568 times)

0 Members and 1 Guest are viewing this topic.

Offline Kowalski

  • Tiger Member
  • **
  • Posts: 92
  • Bike: 2011 Tiger xc
  • Location: Victoria,Canada
Surprised by valve clearances out of spec again
« on: February 24, 2020, 01:21:50 AM »
The previous time i did my valve clearance check was at 69k and i had to reduce shims on 11 of 12 valves and i shimmed them to middle spec.
The bike now has 97k on it and i was surprised to find that 5 out of 6 of the intake valves were below spec, two were at 0.04. Only one exhaust valve was slightly below spec. In my experience, the exhaust valves are the ones that normally need to be re shimmed more often.

Anyone else ran into this issue? Thanks.

Offline Rtwo

  • Tiger Jedi
  • *****
  • Posts: 4280
  • Bike: KTM 1290 SAS
  • Location: Co. Durham
Re: Surprised by valve clearances out of spec again
« Reply #1 on: February 24, 2020, 06:47:01 AM »
I'd probably want to look at the valve seats with a bore scope
You can get a very acceptable one on ebay these days for pennies
The party told you to reject the evidence of your eyes and ears. It was their final, most essential command.
....George Orwell

Check the Facts !!

Offline awjdthumper

  • Tiger Member
  • **
  • Posts: 40
  • Bike: Tiger 800 XCA
  • Location: Abingdon
Re: Surprised by valve clearances out of spec again
« Reply #2 on: February 24, 2020, 01:44:38 PM »
*Originally Posted by Kowalski [+]
The previous time i did my valve clearance check was at 69k and i had to reduce shims on 11 of 12 valves and i shimmed them to middle spec.
The bike now has 97k on it and i was surprised to find that 5 out of 6 of the intake valves were below spec, two were at 0.04. Only one exhaust valve was slightly below spec. In my experience, the exhaust valves are the ones that normally need to be re shimmed more often.

Anyone else ran into this issue? Thanks.
On the positive side, the exhaust valves and seats are doing very well! The explanation for the inlet valves might be that the exhaust valves are made from a harder material to prevent valve seat recession and therefore stretch less than the inlet valves which are closing up their clearances.
Suzuki GSX1400, Armstrong MT560 + collection of classic British bikes

Offline AvgBear

  • Tiger Jedi
  • *****
  • Posts: 2878
  • Bike: '12 Venom Roadie
  • Location: Missouri USA
Re: Surprised by valve clearances out of spec again
« Reply #3 on: February 24, 2020, 05:37:50 PM »
*Originally Posted by awjdthumper [+]
On the positive side, the exhaust valves and seats are doing very well! The explanation for the inlet valves might be that the exhaust valves are made from a harder material to prevent valve seat recession and therefore stretch less than the inlet valves which are closing up their clearances.
:0461:
My experience has been that, with high-mileage (nr 100K mi.) mc engines, inlet valves seem to suffer. Engines designed with performance in-mind don't want anymore valve than necessary obstructing the, power-producing, intake flow.
OTOH, engines tend to respond quite well to precision cylinder head re-working/refurbishing.
There are a terrible lot of lies going about the world, and the worst of it is that half of them are true.
WSC

Offline Kowalski

  • Tiger Member
  • **
  • Posts: 92
  • Bike: 2011 Tiger xc
  • Location: Victoria,Canada
Re: Surprised by valve clearances out of spec again
« Reply #4 on: February 25, 2020, 12:08:57 AM »
Thats all good insight, thank you. I'm not overly concerned as yet but will just re shim and keep an eye on them.
There will be 10 valves with 2.30mm shims and 2 with 2.35mm to bring them all back in spec.

Offline stevedo

  • Tiger Master
  • ****
  • Posts: 320
  • Bike: 800XC
Re: Surprised by valve clearances out of spec again
« Reply #5 on: February 25, 2020, 04:47:55 AM »
I recently checked mine at 68,000 miles and found all inlets to be tight. All shimmed to top end of spec. Exhausts were all in spec. I'll check again at about 80k miles to keep an eye on them. Like you I was surprised to find the inlets had closed up.

The maintenance log and photos for Tigger on our RTW trip can be found here: http://www.tiger800rtw.com/tigger-maintenance-repair/ (don't worry, no adverts etc. I don't attempt to monetise my blog or advertise in any way).

Saludos
Steve
www.tiger800rtw.com
facebook @tiger800rtw
Orange 800xc ABS travelling around the world. Currently in Chile. www.tiger800rtw.com or https://www.facebook.com/Tiger800RTW/

Offline Kowalski

  • Tiger Member
  • **
  • Posts: 92
  • Bike: 2011 Tiger xc
  • Location: Victoria,Canada
Re: Surprised by valve clearances out of spec again
« Reply #6 on: February 25, 2020, 06:00:25 AM »
*Originally Posted by stevedo [+]
I recently checked mine at 68,000 miles and found all inlets to be tight. All shimmed to top end of spec. Exhausts were all in spec. I'll check again at about 80k miles to keep an eye on them. Like you I was surprised to find the inlets had closed up.

The maintenance log and photos for Tigger on our RTW trip can be found here: http://www.tiger800rtw.com/tigger-maintenance-repair/ (don't worry, no adverts etc. I don't attempt to monetise my blog or advertise in any way).

Saludos
Steve
www.tiger800rtw.com

Thanks Steve, good to know our bikes are running very similar! Mine has also been down to Tierra del Fuego!
Looking at your log, you've had almost identical issues. My gearshift pin sheared off in Puebla, Mexico. My front brake disks are almost a millimetre below spec, so i just took a hammer to the bobbins to tighten `em up!

Good luck on your travels, i remember reading your blog a few years ago, can`t believe you are still at it!
Cheers, Mike
facebook @tiger800rtw

Offline Eskeemo

  • Tiger Member
  • **
  • Posts: 20
  • Bike: Tiger 800 XCA
  • Location: Northants
Re: Surprised by valve clearances out of spec again
« Reply #7 on: February 25, 2020, 08:16:41 AM »
*Originally Posted by stevedo [+]
I recently checked mine at 68,000 miles and found all inlets to be tight. All shimmed to top end of spec. Exhausts were all in spec. I'll check again at about 80k miles to keep an eye on them. Like you I was surprised to find the inlets had closed up.

The maintenance log and photos for Tigger on our RTW trip can be found here: http://www.tiger800rtw.com/tigger-maintenance-repair/ (don't worry, no adverts etc. I don't attempt to monetise my blog or advertise in any way).

Saludos

Steve
www.tiger800rtw.com
facebook @tiger800rtw

Wow ! FairPlay to you , thanks for sharing link Im going to read through your adventures from the beginning. 👍🏼

 


Recent Topics


winded-staunch