Triumphrat

entropy · 03-01-2005

hello all,

last night i pulled my carbs and airbox on my '98 tbs and noticed what i think is an absurd amount of build-up on all six intake valves. now having just bought the bike last august this is my first big endeavor into the mechanics of the thing. my plan is to: oil change, coolant flush, clean and adjust carbs, clean air element...blah, blah...anyway the point is i have a pretty good mechanical background but i'm looking for advice as to what i should do with this build-up. having never really dealt with anything like this before and not wanting to go deeper into the engine what kind of options should i explore. btw, i plan on removing the pipes tonight just to get a look at the other side of the head. i can also try to post a pic if anyone cares to see what the valves look like..

thanks

benthepaint · 03-01-2005

I have a 98 TBS as well, what kind of build up is it, when i got my bike (used 2790 miles) it started every time straight off, at the 6k service i had three shims that needed replacing and it had become difficult to start, i had in my ignorance used easy-start to get it going which gummed up the air filter and also coated the valves with a sort of tar, this might be the same sort of problem you are experiencing, do you know if the previous owner used anything like easy-start it might be worth a phone call to find out, it was easy to sort out once i knew what the problem was, THROW AWAY ALL MY TINS OF EASY-START and get a new air filter, the valves were easily cleaned with thinners, Hope this is of some help.

ride safe Ben :-g

Guttermonkey · 03-01-2005

I would suggest starting with quality fuel. Chevron, Texaco, Shell. Then you may want to add some Techron. Techron is meant to be added to an automotive fuel tank. So don't add the whole bottle. I'm in the auto service biz. When we have carbon build up problems, the common thread seems to be people that try to save a few bucks by buying the cheapest fuel they can find. Pay me now, pay me later. There are top end cleaners. I would go with one from the auto manufacturers. GM has a good line of chemicals. Since we are a Honda dealer we use their stuff. It is top of the line stuff.
JR

jimmyj900 · 03-01-2005

Carbon build-up on the intake valves would be a very bad thing.

It would mean that combustion was taking place on the inlet side, so unless you've got backfiring through the carbs or your carbs regularly catch fire that's probably not it.

The other possibility for carbon build-up there would be leaking valve seals and very hot valves. If the exhaust is not smoking at an idle (when vacuum is highest) then it's probably not leaking valve seals.

That basically leaves fuel deposits as the source of build-up.

What are you running for fuel?

Jim

mecscc · 03-02-2005

Unless you are just desperate to tear into the bike, why not run about three or four tanks of MMO, at ratio described on the bottle, through the gas? It is a good solvent and should remove the buildup - and clean out any gunk (scientific term) in the carbs while you are at it. I run a few tanks of MMO in all the bikes every spring anyway, just to clear out the buildup over winter, even though I run Stabil in the bikes all winter long. Don't laugh. MMO works; and has for over 50 years.

Monte

entropy · 03-02-2005

unfortunately, with the camera i have none of the pics i took turned out that great. nonetheless, having got the bike in early september w/ shifty tires and not much time to ride i tacked on only 300 miles to the existing 3000 and having only filled the tank a handful of times it was always at least 93 octane. however, having shipped the bike from washington state to michigan the previous owner drained the fuel and i had a tough time starting it until i used starter fluid (which i assume is the same as easy start) and then again recently after it sat for at least three weeks.

as far as backfiring through the carbs, they really don't show any sign of that. at idle the exhaust popped (which i found is common) also at deceleration but i don't recall any smoke ever from the pipes, the tips aren't even black or sooty.
fyi the build-up looks crusty or flaky

my pics won't work but this is pretty close to what mine look like (not quite as bad though)

http://www.wrightrace.com/VET157.JPG[/IMG]

thanks again

entropy · 03-02-2005

that's actually a great idea, i had read some old posts on mmo a while back and forgotten about it, thanks for reminding me. anyway, pulled the pipes and the exhaust side looks "normal". also about an hour ago i put a dental pick to one of my valves and the carbon seemed to flake and come off fairly easily. also wondering if there is anything else i should do while i am at this point. by the way what is the deal to adding the k/n pod filters to an otherwise stock bike..

thanks once again

jimmyj900 · 03-02-2005

Quote:

my pics won't work but this is pretty close to what mine look like (not quite as bad though)

http://www.wrightrace.com/VET157.JPG[/IMG]

That's got to be an exhaust valve in the picture -- after the rings or valve seals have gone bad or the engine has been running extremely rich.

My best guess on what you describe on the intakes would be dried wax/tar from really cheap gas and the suggestion of adding cleaners (fuel injector cleaner, carb cleaner, etc.) to the gas is a good one.

Before you do that, remove a float bowl and take a look inside. If it's not clean and shiny in there, remove all the float bowls and clean them before you add the cleaner to the fuel.

If you've got varnish and gunk in the bowls a cleaner can knock this loose all at once and clog hell out of your carbs (personal experience!) so clean the bowls first and save yourself a major headache.

Jim

entropy · 03-02-2005

i will do that as soon as i get home today, thanks for the advice.