'84 XT600 high oil usage
 

Hi Guys,

I need to find out if there is some way of reconditioning the piston rings on my '84 XT600 instead of replacing them. The oil usage on the bike is extremely high (0.5L of oil for every full 28L tank of fuel).

Because I live in SA I cannot find a place locally that stocks the rings and most online shops such as e-bay advertises the required product but the sellers do not deliver to SA.

Thus....can the rings be reconditioned without any heavy engineering work involved?

Please note: I am not a mechanical genius and I am still learning what I can from the clymer manual that I bought for the bike. I have only done minor maintenance on the bike, and have never attempted something as big as opening up the engine or gearbox. Wanna try and sort out the bike....dohdohdoh

Thanks.

Oh dear that does sound as if it's something which needs sorting NOW!

I think most single cylinder thumpers burn a bit of oil but not as much as you describe here. As you know I'm no mechanic but I would imagine it's probably worn/cracked piston rings or excessive engine wear? Not necessarily terminal but something which needs to be sorted out before riding again. :(

I presume the bike has probably had a hard life / high mileage? On the face of it a little concerning BUT I have known the old venerable XT engine to go on and on and on. I have heard of one old XT600 (1986) engine which has done 200,000 and is still going strong. Not many engines can claim similar longevity.

I wonder if there are forum members near you in South Africa who may be able to point you in the right direction? Have you tried making contact with any through this or another bike/travel forum?

I appreciate it's sometimes very difficult for you chaps in South Africa (and throughout the African continent) to source spares etc and that sometimes instead you need to implement and adapt with whats at hand. I have seen locals in West Africa (Gambia, Ghana and Sierra Leone mainly) sucessfully bodging car engines that are nearly 50 years old. Amazing!

We take it for granted we can always find the right spare parts (often at considerable cost it must be said). I take my hat off to you and all others in the third world who are managing to remain mobile in such a difficult & demanding environment.... :clap:

No, if they are worn, they are worn & half a liter of oil per tank is pretty bad.

I have members from SA on my forum & i don't think they have problems sourcing parts for there 84 XT`s.

You have Yammy dealers in SA they will sell you some rings, but it may be time to go one oversize now? re-bore, new piston & rings, and it will be cheaper to buy an aftermarket kit in that case.

To do it properly & to get long life your looking at $3-500 bucks.

Mezo.

well... it's not easy to replace the piston and rings if your not too mechanically inclined...

150 bucks for a Wiseco 97mm piston+rings+wristpin+c-clips:

Wiseco Piston Kit Yamaha XT600 84-96 97mm | eBay

YAMAHA XT600 WISECO PISTON KIT 1MM OVER XT 600 84-96 | eBay


The first link, the seller says he also sells the top end gasket if you need it..

Three hour labor is more than enough to get the old piston out and fit the new one in NOT counting the time/money for to rebore the cylinder sleeve...


Vando beer

97mm bit big
 

Vando,
97mm is about 4th oversize, the early XT's were 95mm bore and then went up in m.5mm sizes.
Quicken,
This is not a difficult bike to work on and should have the barrel taken off and measured before buying the replacement piston, look for oval or badly scored bore.
Like Mezo said,
get a rebore, do it properly and you will reap the rewards with a Great bike.:funmeteryes:

Oh.. Ignore the first link on the previous post of mine.... I thought they were 96mm stock.... my bad... STILL, link #2 is a valid option!
Still, if his engine is burning up that much oil you can surely skip first size up and go to the 2nd size overbore if it's in that bad shape..


WISECO 96mm:

Stock compression: Wiseco Piston Kit Yamaha XT600 84-96 96mm | eBay

High compression: Wiseco Piston Kit Yamaha XT600 Hi-Comp 84-96 96mm | eBay

Keep in mind, +1mm overbore is in diameter! so it's 0.5mm increase from center to wall..


Vando beer

Thanks for all the information guys. I think the milleage is REALLY high, but got the bike for a real bargain (Equivalent of 250 pounds) and it actually still runs very well for it's age. I was really hoping to just replace the rings as I would have to find an engineering company who can do a rebore for an oversized piston, but it seems that it might be the obvious solution to do so.

The Yamaha dealers around here charge an arm and a leg for parts, if they can still source them (and if they are prepared to help as customer service sucks in this country) so I agree with you Mezo that I'd rather try and see if can find an oversized piston and someone that knows what they are doing when it somes to reboring the engine....will be nice to have a bit more power from the old muel.:biggrin3::biggrin3::biggrin3:


The price of the Wiseco kit is really not bad seeing as replacement rings for the existing bore and piston will cost me half as much, so it might just be worth the effort. I'll also just respray the block with black engine paint while I'm at it to give it a new look....all the paint has sadly dissapeared over the years.:(

I am aiming to rebuild this bike completely but it completely depends on funds and time at this stage. I also use the bike quite regularly to get to work and back so that leaves me without transport for a while.

Thanks for all the VERY helpful information guys. I really appreciate that I can come and ask for advice from people who know what they are talking about.

Thanks bacardi, I checked out the updated links. I'll have to take chucky's advice and I think I'll have to open her up and check the current bore diameter first (will prove to be quite a job I suppose).

I think this bike has been through many owners, and it is very possible that someone has already rebored the engine to a larger diameter.

Rebuilding my xt with similar problem 110 000,

I was lucky to find a new old stock Cylinder and pistion from bankrupt yamaha dealer for 200 euros!:D
So just need to work on head and now

Whilst you have the barrel off take a peek down inside at the gears for any chipped teeth, at that mileage id say your going to see some? unless its already been done?

And pop out your valves & check the seats & faces of the valves as well, may need to get them re cut.

Mezo.

Mezo....now you are starting to give me the creeps about rebuilding my bike's engine. I'm scared I start finding other little problems while at it and then won't be able to fix it because of low cash flow or no part availability.

Parts are not the problem, cash can be.

Its common for the 5th gear to be chipped, sometimes others.
You will normally get away with big end bearing & stuff like that but whilst the motor is in bit you may as well fix the knackered parts.

Nine times out of ten it just needs a new piston/rings & often replace the 5th gear, then there's tens of thousands of happy riding kilometers afterwards.

Yamaha made a pretty reliable pushbike in the XT600, look after it & it will reward you with many years of riding.

Mezo.

Thanks Mezo,

I'll check that fifth gear - it does make a funny whining noise when the bike is running in that gear....

Just as a matter curiosity - Can I just replace rings without doing anything about the cylinder bore? Purely asking as I think that just engineering the cylinder will cost me quite a few bucks.

What is the standard size for the rings, because I don't completely understand the Clymer manual's measurements (Something like 94.00-97.00,95.00 - can't remember exactly). If the diameter of the cylinder is standard what size rings should I be looking for?

I really just want to sort out the high oil usage issue and replace the gaskets.

Yes if its not to worn you can just hone the barrel with a honing brush & fit new rings.

http://www.hn-sf.com/infoimg/20101224153853327.JPG

Mezo.

And im guessing your next question will be can i fit new rings without honing?

No, your barrel will have a glaze on there & fitting new rings will need a hone to allow the rings to bed in to the freshly de-glazed/honed barrel.

You cannot simply put new rings in, your initial problem will still be there (smoke trail for miles pissing every motorist off behind you)

Mezo.