Yamaha Star Stryker banner

Any guesses???

3674 Views 22 Replies 7 Participants Last post by  sfcmcgan
So.. My6 bike has a sever issue... I had to put it in the shop (Hinshaws motorcycle in Auburn).. it has the mech's baffled!!! Here are the symptoms:

1. rear cylinder has very little (i mean very little) exhaust. Kinda like when you breath fog on a window. the little it has gets very hot compared to the front cylinder. make a wierd "Psst, Psst Psst sound at idle.
2. engine light does NOT illuminate. But the fuel meter seems to be stuck at full bars even though I have less than a 1/4 tank fuel... this could be a different issue...not sure.
3. Rear cylinder has good compression... good spark.
4. using the Diagnostic mode... both injectors check out as good.
5. both cylinder run at approx 10 degrees diffrent from eachother... 201 -211.. these flux slightly... but nothing out of the ordinary. ( side note... if you measure either front or rear temps just below the plastic chrome covers... 1 side will be way warmer than the other... just FYI)
6. The bike still produces power and is totally ridable. there is power loss, but I could hit 60 fairly hassle free.
7. Gas is good (someone would ask)... drained all the fuel and replaced with fresh gas.
8. there is no strange internal sounds. Used a stethescope and listened.
9. there is no smoke coming out the oil filler hole... nor is there water in the oil.
10. no backfiring of any kind either thru the exhaust or intake.

Last thing... I completely disconnected the Cobra powerpro tuner and hooked up the stock config (much easier the 3rd time)... same issue...

My diagnoses is a bad fuel injector (I pray that is what it is!!!), but nobody at the shop had ever seen this particular issue.... I will let everyone know when I do... but your opinions are welcome!!!
1 - 8 of 23 Posts
11Stryker said:
You got it with the Injector! Good Compression, Good Spark, Very little exhaust means very little fuel.
Brother... I hope so!!! Could be an ECU issue... Injector is WAYYYY Cheaper!!
Urban... that is a possibility... I did not check it.. but they will I am sure....

Mentax... ECU has definately crossed my mind and I have not ruled it out... but I have no idea what the readings would be as far as an ocilloscope nor do I have one... but ... me being kind of gadgity... I might have to invest in one...

Another thought has crossed my mind sitting here thinking about it... could be as simple as a slightly clogged fuel line... but that should only be the case if it was the second injector in the line... Could someone check and see which injector gets fuel 1st?
SR71 said:
Straightjacket said:
It's really hard to troubleshoot without seeing the bike and being the one testing it. Knowing what the mech. has actually done? With that being said and how new the bike is, I would definately check the pipe for an ubstruction. A friends kid was trying to help him work on the bike by putting tools in his pipe, you never know? Someone else mentioned a broken baffle, I think it was the same pipes? You said you had spark, but is it at the right time? Or all the time? Maybe a bad pick up coil? Someone else also mentioned the coil wire on the rear cylinder being loose?
I don't think you would have a higher exhaust temp on that cylinder if it was a spark or fuel issue. Sounds like exhaust valve not opening (there are two per cylinder) or timing.
I am not going to say it is a "higher" temp... more like the heat is just lingering in the pipe due to lack of enough force to "thrust" it out.... But yes Valves are still on my list.

the broken baffle, and coil was my bike also... but the baffle was on the other pipe (by the way V&H sent me a new one free of charge). and the coil checked out fine via resistance test.... I have 5377 miles on the bike... No word yet from the service dept.
Straightjacket said:
Rear cylinders allways have a higher temp on a v-twinn, they get all the heat from the front cylinder on them. On a carberated version you would jet them different to compensate.
If I had rode the bike for any time when I took the readings I would agree... but it was cold when I started it and it never moved... just sat on my shop floor.
50ccRdRash said:
As a guess.... Cracked/broken or faulty injector..or maybe crank sensor..???
Hmmm... crank sensor... never thought about that! New possibilty....
So i took the bike into Hishaws... the techs looked it over and could find nothing wrong with the system other than it has freaky symptoms... UNTIL... a young mech decided maybe someone crammed a potato up the pipe... guess what??? Not a potato but a baffle that collapsed!!! Yes the baffle welds broke and allowed the part with the holes to slide down and stop up the exhaust!!!! You might remember I had an issue just a couple of weeks before with the other baffle welds breaking and it was rattling around.

The biggest issue was the severe backpressure could have caused several major failures in the engine!!! Fortunatly... My bike is fine!!!

So I call V&H and have the call Hinshaws motorcycle to get the facts from a certified mechanic... bottomline folks... there could be a recall on ALL of the following baffles:

21897 - Competition Baffle
21899 - Quiet Baffle

Not sure if V&H is going to pick up the tab... but I should find out tomorrow...

Suggestion: pull your baffles and check to see if the welds are loose and or broken....
See less See more
Straightjacket said:
"With that being said and how new the bike is, I would definately check the pipe for an ubstruction. A friends kid was trying to help him work on the bike by putting tools in his pipe, you never know? Someone else mentioned a broken baffle."

Ya we all thought it, just took awhile for the shop to check?
You said it brother!!! Good call!!
1 - 8 of 23 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.