Me head

Questions regarding the DR800

Me head

Postby GrahamW » Wed Apr 17, 2019 9:48 am

Hi I am waiting on my new cam chain tensioner to come from Megazip so looking at the last few things I need to do to get my engine back together after getting my new piston and cylinder rebored. It looks like at some point in the past the cam chain tension went and a previous owner rebuilt the engine but kept the piston and damaged cylinder. When I had the bike it was running ok apart from running hot and the output shaft bearing going that caused me to take the engine apart in the first place.

I am thinking I should remove the valves and clean them up and fit new valve seals, I did this before on my old KLR650 and found the tool I used for that in the bottom of a storage box in the shed. On my KLR I cleaned up the valves with oven cleaner and all sorts I think and it was a pain but I have seen this video on youtube of a guy making it look easy with a drill, a scotch brite pad and a can of some American stuff:

https://youtu.be/KLrUnEEeZrk

Is that a good idea? Also in the garage I have the tool that is a stick with suction cups on each end a two different containers of cutting compound should i use this as well to grind the valves in after they are cleaned up with the drill? My only worry is residue of cutting compound getting left around. It does look like my valve seals were leaking a bit as there is black from oil on them and the top of the piston looked quite coked up. Also Wemotos do valve seals for a couple of quid each listed for a DR800 but the OEM parts are like 15 am I ok to go with the Wemoto ones surely there can't be much in a basic thing like that?

Image
Image
Image
Image
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Re: Me head

Postby nug » Wed Apr 17, 2019 1:21 pm

By all means grind the valves if they need it, but make sure you don't do more harm than good. Most people tend to over do it and create a larger sealing surface which actually creates a poor seal and other issues.

The wemoto valve seals are likely fine, but its a big job to replace them if they are crap. A bit extra money spent now as compared to having to do the job again?

Any head work should be followed by a thorough washing and flushing with clean degreaser. Then you must blow out all the oilways with compressed air to be sure they are clear. i would would do this more than once to be sure.
Last edited by nug on Wed Apr 17, 2019 6:41 pm, edited 1 time in total.
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3270
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: Me head

Postby GrahamW » Wed Apr 17, 2019 1:51 pm

I think what I will do is take the valves out and inspect the sealing surface at the very least will replace the valve seals with new ones. I am not sure I am setup for washing the entire head in degreaser how about a dish bowl and some petrol in the garden and then the compressed air when its dried out. I have a jerry can of year old petrol mixed 50/1 with 2t oil that I use for cleaning parts.
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Re: Me head

Postby BigBob » Wed Apr 17, 2019 6:09 pm

Definitely use OE valve stem seals. As Nathan says, having to take the engine out and rebuild the head because you have used shite Chinese ones is not a good idea.
User avatar
BigBob
Admin
Admin
 
Posts: 3831
Joined: Sat Jan 23, 2010 10:46 pm
Location: ESSEX

Re: Me head

Postby GrahamW » Wed Apr 17, 2019 8:04 pm

It makes sense then to get the proper Suzuki ones then even though the pattern ones might be the same just incase. Only thing I just thought what if the proper OEM ones have been sat in the warehouse for 20 years and the cheap ones were made 6 months ago or do Suzuki refresh the stock with things like that? I hope I don't spend good money doing things properly and end up like OldGit in that other post who's bike wont start.
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Re: Me head

Postby nug » Thu Apr 18, 2019 12:20 pm

Good point about the shelf life of parts. I guess this is a potential issue that is an unknown quantity. That said, I have never had an issue. You could probably find quality brand seals that you could match up if you wanted to go to those lengths. Still doesn't mean they are not old stock though. Maybe cross reference the part no and see if they are common to another bike. If they are, they may have a higher turnover of parts which means stocks will be fresher.

You can clean the head with the concoction you describe, but I would still flush it with a clean product such as brake cleaner or white spirit before blowing out with an airline.
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3270
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: Me head

Postby GrahamW » Thu Apr 18, 2019 1:39 pm

Cheers Nug that sounds like a plan then for the cleaning up of the head. Bath in petrol and then a blast with brake cleaner that stuff comes out under pressure so will be good for the oil channels. I guess all the springs and bits will need a fresh coat of engine oil before it goes back together.
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Re: Me head

Postby nug » Thu Apr 18, 2019 8:23 pm

Yep lube everything up during assembly. Put some grease or assembly lube (thicker/heavier than oil) on the cam lobes and rockers as well. The most wear and damage is done at start up so you must avoid a "dry" start at all costs.
User avatar
nug
Site Supporter & all round Good Egg!
Site Supporter & all round Good Egg!
 
Posts: 3270
Images: 14
Joined: Sat Jan 23, 2010 10:46 pm
Location: Lincoln

Re: Me head

Postby GrahamW » Thu May 02, 2019 1:17 pm

So I have the head apart now and am looking at cleaning everything up and lapping the valves in using the lapping tool I am not sure how mad to go with cleaning the valves up, should I use that method with scotchbrite and a drill first to get them shiny or should I just clean them up with brake cleaner and a rag as best I can and lap them in using the stick tool and fine compound and then clean everything up again as per Nugs suggestion?

I went for OEM valve seals BTW and they should be arriving tomorrow. Also the valves slide up and down ok with no sign of damage.
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Re: Me head

Postby GrahamW » Thu May 02, 2019 3:43 pm

I gave the head a good clean for now first with petrol and then with hot water and washing up liquid followed by a blast of brake cleaner and a bit of WD40 down the oil feeds and to the cam journals and the valve sleeves to get rid of any water and prevent any rust. Next job is to give the valves themselves similar treatment before lapping them in a bit and repeating the cleaning. Hopefully I will have the head back on this weekend.
GrahamW
On Here A Lot
On Here A Lot
 
Posts: 263
Joined: Thu Oct 26, 2017 10:10 am
Location: Littlehampton West Sussex

Next

Return to DR800

Who is online

Users browsing this forum: GrahamW, Megamoto and 2 guests

x