Valve Stem Seals, or maybe throw in the towel

[KiwiAlfa156]

Sounds like its running on three cylinders. Check the temp of the header pipes.

[Baatfam]

Thanks, Bob. I’ll consider it. Harbor freight has a few that are reasonably priced. But how do I know if they have the right adapter to fit the threaded hole in my intake port?

There is really nothing special about the Suzuki spark plug threads, as far as I know, but you can google it.
The craftsman kit has covered everything I've tried it on.

[Rich82GS750TZ]

Rich, I sorta remember seeing a bit of smoke last time we were riding. Compression tester is a very good tool to have. Helps you figure out if you need valve stuff or ring stuff. I'd get one.

Yeah, I’ve been on borrowed time.

Rich, I have a Craftsman compression tester, (#47089 if you want to google it).
Send me a PM if you want to borrow it. We'll have to check on shipping each way, but otherwise it's yours to use.

Thanks, Bob. I’ll consider it. Harbor freight has a few that are reasonably priced. But how do I know if they have the right adapter to fit the threaded hole in my intake port?
https://www.harborfreight.com/quick-connect-compression-tester-62622.html?utm_source=google&utm_medium=cpc&utm_ca mpaign=12144811130&campaignid=12144811130&utm_cont ent=117789278878&adsetid=117789278878&product=6262 2&store=830&gclid=CjwKCAjw6p-oBhAYEiwAgg2PguHcessS93VmR_aMK6M15_UoBG_tUWHOA4WvI dibSC-W1vCdkNeAIRoCcakQAvD_BwE

I just put in 4 new B7EA plugs, went for a 1/2 hour ride. No change. Here’s a video of what she sounds like. After the bike cools down I’ll pull the plugs and post a pic. I think it’s just about beer:30.

[KiwiAlfa156]

Just my 2 cents worth as the owner of a GS650 that is drinking oil and smoking a little on cold start up and when being ridden hard. I restored it about 3 years ago and dismantled the top end and barrels. The ports tidied up, new valve seals, valves and seats redone, everything measured and reassembled. I (mistakenly it turns out) gave the barrel a hone and didn't replace the rings. After running in the engine, all four pots showed excellent compression but oil consumption wasn't good and hasn't improved. The engine makes really good power. I pulled the plugs and they looked a lot like yours with a crust of ash (but no carbon fouling) on all 4 plugs from burning oil. My theory is that the hone has seated the compression rings which had enough meat on them, but wore out the oil control rings which may be did not. It got fresh viton valve stem seals, so the likelihood of it being stem seal related is slim. It smokes on cold start up which according to the 'internet' is a classic sign of worn stem seals... although badly functioning oil control rings and the bigger clearance of cold motor might, to my mind, yield the same results. Compression and leak-down testing will give you some clues on the state of your compression rings and valve seats, but won't tell you anything about the oil control rings. I'm on the cusp of ordering fresh rings and gaskets.

[Baatfam]

Rich, I have a Craftsman compression tester, (#47089 if you want to google it).
Send me a PM if you want to borrow it. We'll have to check on shipping each way, but otherwise it's yours to use.

[Eli69]

Rich, I sorta remember seeing a bit of smoke last time we were riding. Compression tester is a very good tool to have. Helps you figure out if you need valve stuff or ring stuff. I'd get one.

[Suzukian]

You can make your own compression tester by drilling out a spark plug from the plug wire connector end, all the way through till it comes out the other end. By using various hoses till you get to the right thickness, you buy a cheap pressure gauge that goes up to 200 lbs., and voila, you have a compression tester for maybe $15 bucks. if you use a Harbor Freight gauge. You just need one to tell you relevant pressures between the cylinders.

[93Bandit]

I will stop at the local Hardware store, MC shop, autoparts, places after work until I find D7EA plugs. Will put 4 new plugs in tonight and go for a 1/2 hour ride or so. See how it runs, Then pull plugs, take more pics and report.

I don't own a compression tester. Suppose I could look for one. I'm sure it's a useful tool to have. I don't have any friends that ride that would have one to borrow.
Recommendations on a Compression Tester with links would be appreciated if we think that's necessary at this point.

I agree with the others. Throw some fresh new plugs in and ride. Monitor oil consumption over a 1,000 mile period if you can. I wouldn't tear it down until you have an exact figure that warrants it. The plugs on my 850 look similar to yours, although not quite as bad. But I don't know how many miles you put on those plugs. I put about 7k miles on mine by the time they got that cruddy. I burn about a quart per 1,500 miles if I keep speeds below 70mph. If I ride the interstate at 80mph, I go through a quart per 800 miles.

As for compression tester, I bought this one years ago, probably 15 or so. I think I bought it at O'Reilly's, it was hanging on the pegboard behind the counter. I think I paid around $50 for it at that time, no idea what it costs today. I've been very happy with it, good enough quality for my needs. It's got adapters for most common plug threads and a couple adapters for hard to reach plugs. I've used it on cars, bikes, small engines etc. https://www.boschdiagnostics.com/pro...ression-tester

[rphillips]

Funny how different folks are. No question do what said and all should be good.... Kind'f embarrassing, but my Honda CB1100F uses appx. qt. of oil every 3 or 4 tanks of gas, has been using oil since I got it, appx 20 yrs. ago, but usage has about doubled within those 20 yrs. Appx 6 yrs. ago it burned a couple of valves, due to lack of maintenance, had the head reworked and put it back on, hoping the new seals may help the oil thing. No, nothing changed, Of course, looking back, I should have gone through the whole thing but too late after it was back together. Still riding it like it is, just make a point to top off the oil while at home so none of my buddies see me, I don't want to put up with them poking at me about my old worn out Honda.

[Nessism]

500 miles/quart of oil is a lot.

I wouldn't bother with a compression or leak down test. I'd just plan on a teardown, and measure everything when it's apart. New rings, gaskets & seals, at a minimum.

[rphillips]

Around here parts stores AutoZone, O'Rileys, Federated Auto Parts, will loan things like compression testers, you put down a deposit and when you bring it back undamaged, they give all your deposit back. Great deal for most folks, How often have you needed one within the past 10 yrs.

[Rich82GS750TZ]

Ditto on the compression/leakdown test. Listening at the dipstick hole would also give you some indication if no. 4 has a ring issue, or, more of a ring issue than the other cylinders.
I can't begin to understand how I could possibly know what I'd be listening for, but willing to learn. We can circle back to this concept.

P.S. Valve stem seals are at their worst under high vacuum. As in deceleration. You weren’t backing off going up that hill so those HDs could keep you in sight, were you?

No, not intentionally. This was at the start of about a 5 mile stretch of twisty roads with no turn-offs. I had intended to wait for them at the next stop sign. This is what I deserve, I guess.

If having to put a qt. of oil in with every tank of gas, yes, probably time to think of something more drastic. If a qt. of oil in 1000 mi., may get it back running like before last Sat. and be good to go again, like the past 2 yrs.... I've always been taught simplest easiest things FIRST... Wondering, do you have a guess on the oil consumption?

My best guess would be about a quart every 500 miles, roughly.

I will stop at the local Hardware store, MC shop, autoparts, places after work until I find D7EA plugs. Will put 4 new plugs in tonight and go for a 1/2 hour ride or so. See how it runs, Then pull plugs, take more pics and report.

I don't own a compression tester. Suppose I could look for one. I'm sure it's a useful tool to have. I don't have any friends that ride that would have one to borrow.
Recommendations on a Compression Tester with links would be appreciated if we think that's necessary at this point.

I'll have to read up on leak-down test. I have never done that before. But I'm open to anything really.

But that's getting ahead of myself a bit.

The power loss happened about 60 miles into the 250 mile ride. I'm sure I didn't do my bike any favors by completing the poker run when my bike was telling me to just head home.


Thank you all for the help so far.

[rphillips]

If having to put a qt. of oil in with every tank of gas, yes, probably time to think of something more drastic. If a qt. of oil in 1000 mi., may get it back running like before last Sat. and be good to go again, like the past 2 yrs.... I've always been taught simplest easiest things FIRST... Wondering, do you have a guess on the oil consumption?

[pdqford]

I'd do a compression test, preferrably a leakdown test too.
Maybe that will give you more info to go on when deciding whether to take the head off or not.

Ditto on the compression/leakdown test. Listening at the dipstick hole would also give you some indication if no. 4 has a ring issue, or, more of a ring issue than the other cylinders.

When I first looked at the plug pictures, I thought no. 1 plug also looked marginal. Interestingly, both 1 and 4 are “outside” cylinders, AND are both fired by the Sam coil. When it went down on power was it misfiring? Continuing to nurse it along may have loaded up no 4? If no. 4 bridged, would that mess up the spark quality of the companion cylinder?

P.S. Valve stem seals are at their worst under high vacuum. As in deceleration. You weren’t backing off going up that hill so those HDs could keep you in sight, were you?

[Nessism]

Ed, plugs are D8EA per the owner's manual. Could you explain to a numpty what one step hotter plug I would look for? I'm thinking that tonight I'll wire brush 1-3 and put the new good spare D8EA in # 4. See how she runs.

D7EA is hotter, which means the plug electrode itself will run hotter, which will help burn off any oil residue that collects on the plug. A hotter plug does not make the engine run hotter. The idea is to keep the plugs from fouling.

Those plugs look to have a lot of carbon on them, even down around the electrode where your wire brush won't reach. I'd get new plugs if you can...