Possible Valve problem?

[Anonymous]

The jets should be screwed all the way in - and tight.

You could have a cam that skipped a tooth.

Cool that is good to know. I couldn't find anything about adjusting the jets in my namual and that is why I questioned doing it.

The bike was beat bad before I got it and I figured it is most likely a cam is out at this point. Hell the bike had studed dirt tires on it when I got it. I'm suprised the bike is in as good of condition as it is.

[Anonymous]

The worst of luck

Well everyone. Here is my story from last night. SO... I get home from work and tear the top off the engine. No big supprise. The last goon to work on the engine had set the cams up for the GS450 (18 pins) instead of a GS425 (20 Pins). So I tear out both cams, adjust everyting put it all back together. Guess what. The engine sounds tons better. But still less power than it had. So I figure OK something else must be off. Check the timing. Hmm. still good. Balance the Carbs. Those were way out but I figured they would be. Ok Whats left. Valve shims. Not getting done due to lack of revenue at this point in time. No oil change either, Might try that tonight. I think I might have to much oil in the engine. Can't tell becuase the stupid window is fogged on the bike.

So I decide Hell I'll take it for a ride and see if it gets better. Let the engine idle for a bit while I put on some riding gear. Get on and take off. Well engine wont get above 3 grand under load. And after about 5 minutes of riding I couldn't get above 2 grand. Yeah that was unsettleing. Being exhausted due to the fact it was 10 PM I put my bike away and turned my attention to my car that also needed repair again last night [stupid money pit].

At this point I'm out of Ideas. I figure that most people are going to say timing or coils. Well I checked the timing, and I have no idea about the coils. If that is what It is then it gets added to the project for next summer. $50 left in the budget and school only 1.5 months away. Time to get busy saving.

If anyone else has any other ideas let me know please.

[Anonymous]

Oil makes no difference

I did the oil change yesterday. No difference noticed in the preformance of the engine. Still under 3 grand. I'm going to bring home an oscilliscope and a current probe tonight and check the coils. At this point I'm not sure where else to check. Although I probably should look at my plugs now and see if they are the color that they should be.

No matter what I find it will be storage time for the old bike. At least if I find it is the coils I can continue my repaint job this winter. Otherwise why waste my time on a bike that doesn't run.

[Anonymous]

Found the culprit. It is the condesers that are mounted with the coils. So those are on order and all will be good.

[DMPLATT]

Wow, I'm impressed. What a nightmare huh?
Keep us posted when you get the condesers.

[Detman101]

Wow, you got lucky. If it was the carburetors I was going to start praying for you. Everything else on the bike is easy.

Dm of mD

[Anonymous]

More good news today. My plates came. Went for a ride today. At a wopping 25MPH. I know it isn't that fast but hey I got to ride it on the road for once (legally at least). But I though I would share that. Oh yeah condesers already shipped and on their way.

[Anonymous]

Firday: So the condesers came and I eagerly installed them. Engine still wasn't running right but was more responsive. So I took it out. Got about 2 miles in before it started to take a dump again. So I limped it to where I was headed and let it cool for a while. Sat with my girl for a while and then had her follow me home with her hazards going. good thing too. Becuase I had to push the thing up some hills. Big hills that it clonked out on. Got home and saw oil dripping to the ground. Engine was almost red hot and couldn't get it above 2 grand. Even donw hill. So I poped the oil cap and found no oil left in the engine. It had pushed it all out of the breather hose for the crank case. So I poured oil in and turned the enigne a few times and let it cool over night.

Saturday: So I get up and decide to see if the bike will still run. Great it does. But the oil cap which takes like 4 turns to screw on blows off the engine(it wasn't tight but spun most the way down) and past my head and oil spews from the engine like and oil well. Well I guess my crank case is getting preasurized. That expains the oil in the air box. So it looks like an engine rebuild job, Rings, Head gasket, and possible a valve seat job this winter if time and money permit. That is of course unless anyone knows what the problem is. I've never had to do this type of work on an engine and have no idea what could be causing it, but I'm willing to investigate and try a rebuild. I will probably buy a real leakdown tester and retest the engine first. Not to sure how well the homade version I have works.

[jonr]

Andy,

Your endurance and committment to this 425 is amazing! I hope you get it fixed soon. The story about the oil cap blew my mind (and apparently it almost blew your head off!). I took interest in your story because I fear the valve shim job myself. Don't know if I need it or not at this point and I don't like getting into the engine if I don't have to. Kudos and good luck!

-jon

[Anonymous]

I'm with you on the valve clearance, I was going to take the old GS1100 out to Oregon from southern Idaho, but he was starting to give problems at cold temps. Then i rode with no helmet for a couple of miles and the top end seemed to noisy. Decided to get my hands dirty and pull the cover off and check me some valves.

Got the thing apart, and it went slow. The Vetter fairing was the worst thing, with u clamps going right up against the motor, no room for a socket so that took some time. like a goof ball I didn't understand the instructions in my manual, so i adjusted every valve to the specs (yes, even the ones with the cam down). But I figured it out, and got everything to where it sould be (by the way, get the tool suzuki has for the screws, five dollars is nothing compaired to the pain of a leatherman). Got the gasket on, then got it on again, then finaly got all the holes lined up right (had mine backwards and upside down ) then started to put it back together.

Then with the bike looking like it did in the first place i fire it up. "clink clink, clink" went my bike. Though it was one of my screws on number four that was too lose so i did the valves on number four again. in the end the same thing is going on. I talked with a couple of mechanics both said cam chain. The guy at the Suzi dealer told me that my bike was realy old and not worth the money of breaking the motor for the cam chain. now what struck me as odd was that the guy said my bike was realy old, 1980 gs1100 with about 40k or 41k miles on it. Odd, heard of some bikes getting up to 200k on them.

at least other than that BEEP noise, the motor sounds REALY good

But anyway, conclusions that i have reached:
1. get a silicon gasket form real gasket (wishing i did)
2. check cam chain tension while you do the job
3. look at the cam chain guide in the valve cover ( :twisted: i think thats my problem)
4. after your all done - relax, have a home brew!

[Anonymous]

Determination with this bike is correct. Unfortunatley this will be shelved for a while. School starts in a month and all money must be diverted to money for school at this point. No one wishes that this bike would run more than I. I have wanted a bike since I was real little and my uncle used to take me out on his kawasaki dirtbike. I finally got this one and had hoped to have it running by the end of the summer. Unfortunately money has been tight with my car eating 1500 this summer and the bike which was free now at 600 with title and plates and the new front end from the tire to the handlebars. Time has been tough as well. I fell madly in love with a girl just after I got this bike and spend as much time as I can with her. She will ride once she gets a HD. Her mother was in a HD gang growing up and gives me *@%^$*@%^$*@%^$*@%^$ about my GS not being a HD all the time. to qoute myself "I ride what I can afford, if you want me on a Harley you buy me one." But yeah I was hoping to ride into the Dells next weekend with my friends when we go there to celebrate all of our 21st birthdays. But like all good things one must wait and be persistant before the payoff is worth it. That first ride when it does run will be sweeter than it could have been this summer. So for this winter or possibly next summer, if I don't have time or money, is an engine rebuild. First time to ever take an engine aprart completely but I don't think it will be that bad. I don't have to pull the crank to hone the cillinders and change the rings. and I don't have to pull the engine from the bike. HUGE+ I don't think the labor will take me more than a couple of Saturdays but I have to see what parts are going to cost. Then find a place to tear the thing apart and not have to worry about inconvienecing anyone...Mom and Dad like to have their grage... So that is the update for now. I will try to update this as I get stuff done. And to everyone who has posted and posts that I have looked at elsewhere on this site. Thank you.

[Anonymous]

I personaly think that pulling the engine would be the way to rebuild it. I think that you could have the engine out of the frame in a couple of hours, time that i'm almost certain that you would make up for in other areas. I've read some about the Yamaha Ventures 2nd gear problem and one guy talked like he liberated the engine in less than a day (for perspective think goldwing).

I'm not sure how many different parts you should replace but ones that i would pull even if they looked perfect is the cam chain guides. might just be me and my experiance, but i think they could be trouble makers and are not a very pricey part.

well, good luck on your motor building and good luck in school. by the way, what is your magor?

Mark "Q" Tanner

[Anonymous]

To tell you the truth my major has changed for Computer/Robotic Engineering to Management Buisness Administraton (IT Managment). But I'm a true tinkerer at heart. There is almost nothing that can't be fixed with a little time and TLC. Last summer I fixed up and old 86 Accord, and this summer was the GS. But I'm not done yet. I will fix it up, besides chix dig cycles 8) , and I am a Cruiser type of guy myself. Heck a crotch rocket would be great but they scare me, to much power and to heavy and expensive for a first bike. I do ride my pocket rocket (86 Honda Spree) whenever I go out and don't need the use of my car. It isn't all that fast but I do learn alot about how much of a dick people in cars can be. I try to practice my riding skill on that. Hopefully it will help once I get my bike running. But for now school starts on Friday. $2500 investment this semester. Man I work and work all summer and I come out broke everytime. LOL oh well, hopefully it will pay off eventually.

[Dink]

Have you removed the smaller cover on the head cover to be sure that breather is clear, fairly obviously this is likely to be the main culprit for your cases pressurising. You also say your plugs are running black, have you adjusted your idle mixture screws at all? this may also be part of the reason it wont rv out , it would be so rich it cant fire, as the plugs are carboning up from extra fuel, this process would take about the 2-3 minutes you mention.
The motor sounds relatively healthy, especially as it is recording 140psi on a compression test, I would not be pulling it down a this stage. It sounds like you are in need of further fine tuning, it may be just mixtures and timing, it may be more than that but I do not think that tearing it down is necessary yet. Plus adjusting and fine tuning is free apart from time, you do mention your tight budget.
The pressurising of your crankcases is the main concern as far as I can see as it will also stop the bike revving freely, once that it found and solved you will only need to finish fine tuning the rest and away you go.
Dink

[Anonymous]

Dink

What you are saying is that all it could be is that my breather is cloged. I removed the cover on it when I did the timing and looked at it. There are just 2 little screens in there. SHould I take those out and clean them somehow and then put them back in. Or should I try and run without the breather cover on and see if it runs better. The thing that concerns me is that all the oil was getting pushed out the breather hose. I know this is normal if you overfill the engine, But as my case was it pushed all the oil out of it. But now that you mention it since I had the breather cover off when i fixed the timing it never reved as high. When the timing was off I got it up to 6 grand. I'll try that if I get some time tonight.

I have not adjusted the mixture screws. They are still under the factory plugs.