Ok, You all know this is obviously not my bike...
But I get tired of not having anything to work on as I own all Honda's So I decided to help my friend get his Warrior running.

Heres the problem.... 87 warrior, Supertrapp pipe. Got bike with engine in a box. tab was broke that holds chain tensioner at timing chain.
Got tab welded checked everything else out and reassembled motor. started bike up, ran pretty well but noticed exhaust pipe at head was glowing red. Not good.... Remembered that owner had said something about stage 2 jetting.... So disassembled carb to see what main jet was in it, 152.5 main jet
stock is 145 here is the question ... do you think that running that rich of a jet could cause overheating? In my opinion overheating comes from too lean of jetting. Put a new spark plug in to try and get some kind of idea but as the engine gets so hot so fast I don't want to run it that long, Spark plug looks brown from the short time it ran. Any ideas? Other steps I have taken are: replaced oil filter, Checked air filter ( it has a K&N filter) replaced gas in tank.
checked the timing , which I really don't know why because you can't adjust it anyway but thats what the manual said to do.( timing was fine) compresion is 120 which is within specs. Heres an interesting note: the manual says that a clogged air filter can cause overheating.... If the airfilter was cloged would this not create an over rich condition? ( I.E lack of air) so then is it plausible that too big of a main jet could cause overheating?
I'll probably go get a 145 main jet tommorow and try it but thought I would get some feedback as to if ya'll think I'm going in the right direction here. Thanks Oh yea ... the needle jet is on the bottom clip place thingy

Running from a 145 to a 152 is not that much of a difference to make it overheat. How does it ride? Maybe something internally is rubbing like the piston slap is too much or something is getting ready to let go. Tell us what you came up with and we need to play some more pool.

I HAD A VERY SIMILAR PROBLEM WITH MINE....LUCKLY I GOT RID OF IT BEFORE IT BLEW UP.........CAUSE IT DID.

Hey Leadfoot good to see your still around, Pool sounds good... How bought boardmansville on thanksgiving? You goin out? You think a worn top end would cause overheating? I did not replace the top end as all was within spec's.

Taco yea thats probably right it would blow up if I continued to run it this way. But I gotta believe that even a Yamaha with proper maintanence/repair will run as it should....

My 86 250R is still running strong.

Does anybody that has a warrior know how hot they generally get? I know a glowing pipe within 5 min. of running can't be right. I'll most likely end up taking it to Jeff Smith in Murrietta ( great mechanic) to help me figure it out, But it p's me off I can't figure it out.

my first thought was that the timing is retarded. a rich condition generally wont caue the pipe to glow red, a lean condition might, but most of the time its retarded timing. could also be an issue with the cam timing since you say there was a problem with the timing chain tensioner. also check for any restrictions in the exhaust, a plugged exhaust could casue the pipe to glow too somtimes.

put some coolant in the radiator

Thanks Kevin,
The bike has a Supertrapp pipe which has plates on the end .... Maybe too much backpressure?
How is the cam timing differ from regular timing? Do you mean that the chain was improperly installed? It starts right up ... I'll try and see if I can mess with that supertrapp a bit maybe take the plates off and see what happens... besides my neighbors yelling at me

Radiators full esco

the cam need s to be in time twith the crankshaft. it could be off by one tooth on the sprokets and still run, but wot run right or very well. normal timing your are refering to is ignition timing, the time at which the plug fires. cam timing is getting the valves to open at the right time.

Hmm well the CDI controls the timing so I cant.t do much about that.... Besides I checked the timing with a timing light and it was right on the money. Thats not to say the chain isn't off a tooth but the bike runs too good for that I think... I'll keep you posted

I would lean towards what Kevin said about your valve timing being retarded. If I remember correctly the timing is triggered by the crank and you would time correctly but stiil could be out of time on the chain.

[ 11-07-2002, 12:01 PM: Message edited by: Oldman ]

Double checked the chain alignment. and its where the manual says it should be. Someone put a 152.5 main jet in this thing stock is 145 I'm going to get a 147.5 and see it this makes a difference pilot jet is stock, needle is in stock position ( If this is the stock needle) ...Mech thinks it is way to rich... Kinda goofy if you ask me...Danm Yammy's

well if a smaller jet fixes it that'll be a first for me, never heard of the exhaust pipe glowin red forma rich condition before

Tres, I will be there for thanksgiving for sure. I do not know about playing pool in G though. I would rather ride while I am there. Maybe some taco tuesday? I have never been to one of those.

Check the valves... They come out of adjustment too...

I would look for the blocked tailpipe (remove almost all of the plates) or...

You have an air leak.
Is it hard to get to idle steady?

Check at the intake and around the base and head gaskets... spray with ether (starting fluid). You'll know right away if you have an air leak.

My dad owns a Warrior that I ride quite often. It's an air cooled bike so it does get hot... but not red hot.

Vor

[ 11-07-2002, 06:20 PM: Message edited by: Voice of Reason ]

Sounds to me like your timing chain is loose. Have you adjusted it properly. If it's loose the exhaust port open at the wrong time and it acts like a blow torch when the exhaust hits the pipe.

Thanks for the replies...
After a thorough grilling by the guy at the yamaha shop ( while buying main jets etc. ) the guy asked me what kind of pipe I have and how many plates are on it. I told him its a supertrapp pipe and I didn't know how many plates there are. So he told me that that would be his first guess and that there should be at least 8 plates , The fewer the plates the more back presure. When I got home I checked and sure enough there are only 4 plates . So I removed them all even the plug on the end ...Of course I had to put the stock main jet in that I bought... So I then started it up and the pipe glowed red.. Then I ran the bike with the choke on and voila the pipe almost instantly lost its red glow. Ah ha I says to myself I should of left that other larger jet in and just removed the plates.. So thats were Kevin and Vor are correct it wasn't so much an over rich or lean mixture I believe but too much back presure. Now my task is to try and match a proper jet. When I had the choke on I believe that was a little to rich (Maybe a lot) because my spark plug now is black. So what I need to do is go up in size from the stock jet to richen the mix but not as much as what the choke was doing Are you still with me? To compound this problem is that it was getting that hot while at an idle So the main does not really come into play ... So does this mean I should go up on the pilot jet? and I guess the first thing I should do is get a hold of another 4 exhaust plates and install them before I start rejetting.
As I will have to reinstall them at some point ( Although I kinda like the sound ) Anyway thanks for all your input. Whats amazing is that I looked at an 03 warrior at the dealer and there has been very little change to these bikes in 15 years! Hello, yamaha engineers, ever hear of a thing called "Water Cooling?" what a novel idea...
Anyway I'll keep ya'll posted on the progress.
Thanks again

Please let us know your final results with the Warrior.

Hey Oldman,
This is what I've deduced so far......
What I have figured out is that I had too few spacer plates in my supertrapp creating too much backpresure ... I had 4 I need 8-10
also my jetting was incorrect. The correct jetting with the pipe should be :
147.5 Main 50 Pilot 2 turns out on the air screw clip in the third (middle) position . Stock jetting is: 145 main 42.5 pilot 3rd clip pos. 2 turns out on the air screw. Thanks to Alba yamaha ( Team Alba) for helping me figure this out! Oh yea they also suggest driling 3, 1" holes in the airbox.
I'm still dialing the thing in and will post any deviations to this once I get it just right.

Thank you for the information. I keep information like this in a file on my computer.

D.L.

Tres, it's not a honda so you don't have to assume there is anything wrong with it to begin with. Four strokes will make the head pipe glow red at an idle. My bike will idle for close to a minute before the pipe glows cherry. You need to ride the thing to get it moving through the air to cool it. With the jetting that came with it and all the discs installed, run it up and down your street after it's been warmed up and check the plug. Same as on a two-smoke, your looking for a cocoa brown color. You can try going up a size or two on your idle jet which might slow down the heat a bit but it's still going to get hot. To think your buddy let a honda guy work on his Yamaha! I really don't think there is anything wrong with it unless the pipe glows all the time, even when it's ridden at a decent pace.

Hey Ben it's all good only if you ride a Honda.

Tres, Ben gave TACO the same kind of advice when he had a Warrior. The Damn thing never worked right so he finally gave up. So what's he ride now? Oh yeah a Honda 400ex and now he's a happy little camper. Another Yamaha rider see's the light. Ben it's time for a change, Ride HONDA.

yep, And I guess it was my imagination that the engine blew up the first time
One thing about that it sure was quiet ... Course it didn't go very far either
BTW I did go up on the "Pilot" jet and the bike can now sit at an idle without the pipe glowing.
You might give that a try on your bike and then sell it and buy a dependable HONDA!!!

quote:

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Originally posted by treshombre:
started bike up, ran pretty well but noticed exhaust pipe at head was glowing red. Spark plug looks brown from the short time it ran.

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If the thing was brown with the original main jet, then it was jetted in properly. Hello! It's an 87! That's 15 years old man! Probobly on the original piston and rings too right? Can Tom's Honda boast that? I didn't think so! D

Glad you got things straightened out. I was gonna have to come down and fix it for you if you didn't.