Valve Stem Seals, or maybe throw in the towel

[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.

[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

[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.

[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.

[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.

[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.

[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.

[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.

[KiwiAlfa156]

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

[Rich82GS750TZ]

Sounds like it’s running on three cylinders. Check the temp of the header pipes.

Agreed. I have no way currently to measure the actual temperature. # 4 is hot, but not as hot as the other 3.

[Nessism]

Check from a cold start. Very carefully touch the headers right after a cold start. You should be able to quickly figure out if number 4 isn't firing... If it isn't, visually check spark next, with the plug held against the engine.

[Rich82GS750TZ]

Ed, before installing the new plugs, I did check spark on each against the head. All 4 sparked.

After my first cold startup with the fresh new plugs shown in the video above, only running for the 3 minutes of the video, I touched each header pipe at the top bend. # 4 was hot but I could keep my thinly gloved hand on it for a few seconds at least. 1-3 were much hotter in comparison. I could touch them but but only very briefly.

Here’s the new plugs after 1/2 hour ride.


Close-up of # 4

[KiwiAlfa156]

Check the carb diaphragm on number 4. I'm having something similar on the 750 Kat and I've discovered some holes in mine. I was doing a WFO main jet plug chop and it suddenly felt like something 'gave' and the performance degraded somewhat, which sounds very much what you describe in your OP. Anyway the story is all here https://www.thegsresources.com/_foru...on-the-kat-750

[Rich82GS750TZ]

Interesting. Hmm, tomorrow evening I’ll take the lid off # 4 carb and inspect the diaphragm.

[Redman]

Rich,
I suggest when checking the exhaust header pipe temperatures, do it about 3/4 minute after cold start up, and again after a couple minutes, before the head and cylinders heat up.
Oh, and just tap the pipes with back of fingers (skin is thinner on back of fingers, if use finger tips the skin is thicker there and delays your detection and then skin is already heated up oww oww. Old boiler operator guy taught me that decades ago.).

That is all I got to help.

(I was expecting new plugs to clear up the symptoms.)