Yamaha SRX600. Rings need doing?

[Icemaestro]

Hi all,

I have a 1991 Yamaha srx600 - monoshock 3sx model that I'm trying to get going after it sat sitting for a number of years. Got it running, but while cleaning the carbs noticed a lot of oil in the airbox, on the main carb between it and the engine, and when I look into the carb manifold intake (sorry not sure the technical term) on the main carb size there is all over the ?valve? Based on this, black/blueish smoke when running and that it fouls the plug every 10min makes me think the rings need doing - does that sound right? And if so, any recommendations in Auckland who I should take it to (I live out west but do own a trailer) and how much I would expect to pay for this given its an air cooled single?

Thanks http://images.tapatalk-cdn.com/15/11/15/56cada5ecfc55eb172882612d5f51af1.jpg


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[nzspokes]

First do some basic tests. I would remove the crankcase vent from the airbox if it has one. Start it and see what comes out of it.

Then a compression test. If comp is ok then I would be looking at valve stem seals.

Could just need to be run through some heat cycles.

But most likely it will need a rebuild.

[Madness]

It's not over-filled with oil?

[Icemaestro]

Thanks, I did remove the vent but haven't got around to cleaning the plug and starting again. the vent itself didn't have oil on it. I do remember thinking there was a lot of oil when i drained it when I first got it, and filled to correct level though.

I don't have any equipment for compression testing etc, unless anyone near me doesn't mind helping out?

Isn't there alo more involved in a rebuild?

[Triumph guy]

I am rebuilding a 1986 SRX 600, mine needed head gasket as well as rings, once stripped down it also needed a rebore and new piston.
I bought a wiseco forged piston complete with rings in standard compression ratio ex the USA, was under $250 including freight.
I have been advised to use a genuine head gasket and cylinder base gasket, which I sourced from Yamaha.
another thing I learned as while it is possible to remove head and barrel with the engine in place but it is much easier to remove the engine.

[Icemaestro]

Bike went off to Aden at restorace a few weeks ago. Leak down test done following which he advised of a leak past the inlet valves, and he recommended a top end rebuild. I don't think the bike is really worth that much money to justify a full top rebuild, any ideas as to cost effective option?

[Grumph]

Bike went off to Aden at restorace a few weeks ago. Leak down test done following which he advised of a leak past the inlet valves, and he recommended a top end rebuild. I don't think the bike is really worth that much money to justify a full top rebuild, any ideas as to cost effective option?

A leak down test will only show you so much. Without actually pulling the head and barrel you're guessing.
If it does need piston and rings, triumph guy's use of aftermarket parts is the most cost effective as OE is f'n expensive. It will certainly need valves refacing and stem seals - neither of which are expensive.

[Icemaestro]

Thanks, should I perhaps get him to take the head off and look, then see if he'll let me order (or if he will order) aftermarket parts? He was more in line with what you said - needs to pull apart to confirm what will need doing. The main concern from my point is the 1k labor cost - if I can get that down it would help...only thing I can think of is remove the engine myself and take it in, and or reducing the amount of things replaced? Unless there is someone on here who would be willing to go through it with me?


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[Grumph]

The main concern from my point is the 1k labor cost - if I can get that down it would help...


Move out of Auckland....

[neels]

If it's been sitting for a long time it's not unusual to be a bit smoky/oily for a while when going again, I've had this with a couple of bikes in the past that had been parked for a long time, after a few runs they came right once things settled in again.

If you have the option, run the thing and keep an eye on the oil usage and smoking and see if it decreases over time, if it does you can save yourself a 1k labour bill, if not you're no worse off than you were.

[nzspokes]

Not to state the obvious but its not got a valve clearance issue? I dont know these motors but are the tappets to tight?

If it were me I would check that first and if that is ok then wip the head off. How hard can it be?

[Icemaestro]

It's been for 6 runs or so, problem comes down to the plugs it keeps killing. Smoking didn't seem to decrease, time it runs for does though


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[Icemaestro]

I have no idea spokes, would that result in a leak at the inlet valves? Googling seems to suggest valve stem seals is fairly common which would explain this....the head needs to come off for this I understand. How do you feel about a project spokes? Haha I'm not sure! Engines are full of wizardry ;-)


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[nzspokes]

I have no idea spokes, would that result in a leak at the inlet valves? Googling seems to suggest valve stem seals is fairly common which would explain this....the head needs to come off for this I understand. How do you feel about a project spokes? Haha I'm not sure! Engines are full of wizardry ;-)


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Plugs are oily? Can be done without pulling the head but not recommended. Again Ive not seen inside one of these. I would guess its pretty straight forward though.

Im just selling one project as no time to do it. But could pop round the odd evening and laugh at you doing it.

[Icemaestro]

Yup plugs are a bit oily and been advised that the deposit things are oil ish. Haha I asked the mechanic if it could be done without doing the head, he said no :-p

What's your project? The cbr? Haha thanks! I'd probably do it if I had a garage and not a long under deck carport with power/lighting


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[nzspokes]

Yup plugs are a bit oily and been advised that the deposit things are oil ish. Haha I asked the mechanic if it could be done without doing the head, he said no :-p

What's your project? The cbr? Haha thanks! I'd probably do it if I had a garage and not a long under deck carport with power/lighting


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Yeah we sold the CBR. Have some projects around the house that need sorting. 4 bikes should really be enough.

And i want to do motor work on the VTR, cams and head work etc.

They are just a 600 single dirt bike type motor? Take one evening to pull the head, another to do the seals and lap the valves then a third to refit. Then the cost is oil and a head gasket set.

[neels]

It's been for 6 runs or so, problem comes down to the plugs it keeps killing. Smoking didn't seem to decrease, time it runs for does though
If it's getting worse not better, then it's probably not going to come right by itself.:weep:

Normally smoking on overrun is caused by worn valve guides or stuffed seals, smoking on acceleration or constant running piston/rings/bore, either way it's head off to find out.

[nzspokes]

If it's getting worse not better, then it's probably not going to come right by itself.:weep:

Normally smoking on overrun is caused by worn valve guides or stuffed seals, smoking on acceleration or constant running piston/rings/bore, either way it's head off to find out.

To be fair I would do the whole top end to be sure.

[neels]

To be fair I would do the whole top end to be sure.
If I was planning on keeping it, so would I.

[Icemaestro]

I'm uncertain on keeping haha but tbh if I'm going to put money like this into it I should!

Spoke to him today and I'll take it back into him as an engine only which will keep costs down a whole lot :-). He'll pull the head off and take a look, then let me know what has to, should be and might as well replace while there with estimates for each option :-).

Next is to find a car paint place that will paint it for me fairly cheapish (do car places usually use 2k paint?), and then while the engine is out need to polish up the side covers that the clear coat has started to go on. Any idea about what I can do about this? Buff back with wire until the finned part and then put polish on it? Or should I/is it possible to get high temp clear coat?


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[nzspokes]

If you are going to take the motor out, you may a well rebuild it in the lounge in front of the TV.

[Icemaestro]

Lol! Here I was thankful my wife bought me my first bike, and lucky to have three! Struggling to get a garage over the line, let alone turn the lounge into a garage ;-). I might give it a go if I had a garage and someone to give me some pointers at tricky bits and lend me a couple of the specific tools I hear one needs.


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