Shop was rejetting and seized my engine!!??

[GASGAS300HP]

Hey all thank in advance for reading my post. I took my Gas Gas 300 Wild Hp ( 2 Stroke ) quad into a local shop today because I hear rejetting is very necessary with these quads running rich from the factory. They dynoed my quad once and said it was fine; the second run after supposedly only cleaning the air filter my quad siezed/locked up?
I guess I'm at a loss according to the owner but I'm not so sure thats ok with me. My quad had maybe 10-20 hours tops on it; all bone stock. Ran great before It was taken to the shop but it had a tendency to drown out plugs if the fuel or choke was on long before starting. Any suggestions for me on how to deal with the shop or I guess ultimately on ordering new parts to rebuild this? ( I didn't sign any release saying it was ok if something happened if that matters?! ) Ughh I hate this but again thanks for reading!

 

[MattR]

Sorry to hear your unfortunate luck. I don't have any personal experience with dynos nor the risks potentially associated with them. I do my jetting old school style by ride-and-feel.

Does the shop have any policies for this type of matter? I would think if you brought it to them for the sole purpose of jetting and they seize your engine for "poor jetting" then shame on them. I would think they should stand behind their lack of expertise and correct their mistakes. That's just me talking from an integrity standpoint.

Now if you brought it to them for "only" horsepower/torque dyno runs, then the jetting was your fault and not theirs. So it really depends on the real situation... how you approached them for their services and what the expectations were for the paid services.

As a side note, you indicated that the first run went "fine" according to them. Did they have a fuel:air ratio meter installed during the run? How did they come to this conclusion? This may give you some ground to stand on since you were relying on their expertise. In the end, it still comes down to their shop's policies and their integrity as a shop to stand behind their work.

Worst case scenario... they won't replace any parts and just claim it's your fault. In which case, I would leave and never return to their shop again... nor recommend them to my friends. Most times our lessons learned come at a price. Good luck!

 

[mountain thumper]

sorry to hear that!
i would definately toll them either make it right or id seek legal council.
im the kind of person that would freak first and go in and threaten the guy with bodily harm... thats why i do all my own work, because you never know when something like that will happen, and i know if anything breaks theres noone to blame but myself, plus im very poor and cant afford professional work

 

[GASGAS300HP]

More detail

Sorry I'm so frustrated and sick to my stomach after today. So he first dyno run was what they called a base dyno run. They did have a air fuel mixture they showed me quickly. I'll get a copy of all this tomorrow; should have today but I was almost at a loss for words. The second run was supposedly after only cleaning my air filter. One thing I learned tonight from talking with dynojet owners and shops dynoing a two stroke you have wind down off the throttle not just drop off dead from a redline hard pull. Letting go of the throttle will seize the engine by cutting off lubrication! Hence 2 stroke; I have video of these guys doing exactly this! Anyway I guess tear down will show evidence. To answer one previous question my quad was none stock sent in for rejetting. Not just for horsepower dyno runs; good point and thanks for your support in the replies.

 

[SpeedyManiac]

Sounds like the shop should be rebuilding your quad.

 

[rpduc]

I have never seen the air filter set-up on a quad but... a thought about them cleaning the air filter. Maybe they didn't get it seated properly when they reinstalled it so it was sucking air?? That would make it run lean too no?

 

[wence]

Surely the air filter was clean before going to the dyno???
Sounds to me as they are looking for excuses.
Make the ba--ards pay I say.
Cheers Mark

 

[GASGAS300HP]

Links to my Dyno Video footage on You Tube..

If interested in helping me build a case or diagnoses here is some video that was taken at the shop; I requested this on each dyno pull and left my camera there. I Hope these links work; I've never used you tube. Funny thing is the videos on my cam corder were only about 45 seconds apart? Seems my 2nd Dyno wasn't recorded?!!

http://www.youtube.com/watch?v=yEX_euuFE_k
http://www.youtube.com/watch?v=Mi2FkJDY1aw

 

[RBD]

There are two things I see in the video;

1) It does not look like there is enough cooling air passing over the bike. The operators pant legs and long sleeve shirt are not flapping in the breeze (so to speak).

2) I am not real fond of the way the operator would throw power down and then back off with the throttle (looks like he closed the throttle) without pulling the clutch and a little free revving before pulling another load.

In my opinion (and I do not know if they were used or not) when putting a engine on the dyno, you definitely need a EGT, CHT and even a coolant temp monitoring. It is very hard to seize an engine when using these types of gauges. In other words, if you pay attention to these gauges, the operator can stop an engine before it blows up. Again, just my opinion.

Ron

 

[ferguscawley]

I run my own dyno shop her in Ireland and run a Dynojet 250i dyno. I agree with Rons comments and would like to add some more :

The air/fuel ratio is unlikely to have been the cause of your seizure. There seems to be plenty of 2 stroke smoke from that exhaust, even at full chat. That tells me that the bike was getting plenty of fuel, assuming your premix ratio was not stupidly oily. My guess is ther seizure was due to an over-heating problem. As RBD mentions, there is no sign of cooling fans active during those runs.

Another thing is that the dyno appears to have an inneffective brake. Usually after I do a power run, I hit the brake on the dyno to bring rear wheel speed down immediatley. On a 2 stroke, I pull in the clutch and apply dyno brake and then blip the throttle during the decel to keep the crank & piston cool. The electric brake on the dynojet 250i dyno will bring the 500kg dyno drum/roller from 170 mph to zero in less than 4 seconds. The drum on this particular dyno seems to run on with very little retardation.

Just my 2 cents


Fergus

 

[bukwheat]

Was this done at a GasGas dealer's shop???? If so, they owe you a rebuild.
If its not, they still owe you a rebuild but good luck getting it.

 

[mountain thumper]

Sounds like the shop should be rebuilding your quad.

lolz paying for a competent shop to do it any way

 

[GASGAS300HP]

I got a dyno sheet from them finally!

Sorry for my later reply all. The shop was not a Gas Gas dealer no. I live in Oklahoma and we don't have one in the area that I'm aware of. This is a company that I've heard was reputatible and has done alot of 2 stroke work.

I called the shop Friday morning at 7am asking for a copy of the dyno; hard and electronic. ( didnt know if they could have tweaked a copy over night; the quad siezed up last Thurs. is this possible?! ) Anyway at noon I called back with no replies or emails yet from them. They said they would have me a copy late that afternoon; I replied kindly I would like it sooner than late that afternoon! By 2:00pm with no reply from them my wife whom is also sick with this incident drove over there and picked up a hard and electronic copy. Turns out our electronic copy isn't working!?

However we had a hard copy that says they did 7 runs on the quad. Max power was 37.85 horsepower.
My copy says operating temps range from 53.23 degrees farenheight to 56.70 degrees farenheight. 56.70 being when it locked up last run. My air/fuel mixture was around 10 during peak power which is why I took the quad in for jetting I heard they were rich from the factory. My gas was mixed at the factory ratio recommended of 50:1. My redlines during each pull were ran to about 10 thousand rpms.

I'd scan the dyno report in but cant from home. Anyway I hope this helps in identifying if the shop did anything incorrectly. At this point I guess it could have been a freak happening on their time but I'm not 100% after reading some of the things everyone has posted. Will this help anyone to help me determine if anything was abnormal or am I just out of luck?

Thanks for your support everyone and I really appreciate the help! One thing I have going for me is I havent signed any waiver; if in fact its their fault I'll go for legal assistance!

 

[GASGAS300HP]

Fergus,

Thanks for your input on this matter. Could the drum not being slowed down by a brake on the dyno cause significant problems or lead to the seizure that happened such as in my quad? I was thinking this would be an overheating issue until I saw the mid 50 degrees farenheight dyno report. ( I posted stats on this in the original discussion ) I have heard that blipping the throttle on after a pull is necessary also which they didn't do. Could that cause any significant damage such as my engine seizing up? Thanks very much for your imput again sir. When owning a dyno does some one like "Dynojet" have recommendations on how to dyno a typical two stroke application? I'd be curious to see if there are any procedures that were or weren't followed in studying these videos. Thanks again!

 

[HydroDog]

My copy says operating temps range from 53.23 degrees farenheight to 56.70 degrees farenheight. 56.70 being when it locked up last run.

I hope those temps were the ambient air temps and not the coolant temps. If they are the coolant temps then you could be looking at a start of a cold seizure problem on there first run.
But after watching the video if they were running it up to 10,000 and cutting the throttle like that and waiting for the dyno drum to slow down, that is a lot of rev's with no lubrication.

 

[ferguscawley]

Fergus,

Thanks for your input on this matter. Could the drum not being slowed down by a brake on the dyno cause significant problems or lead to the seizure that happened such as in my quad? I was thinking this would be an overheating issue until I saw the mid 50 degrees farenheight dyno report. ( I posted stats on this in the original discussion ) I have heard that blipping the throttle on after a pull is necessary also which they didn't do. Could that cause any significant damage such as my engine seizing up? Thanks very much for your imput again sir. When owning a dyno does some one like "Dynojet" have recommendations on how to dyno a typical two stroke application? I'd be curious to see if there are any procedures that were or weren't followed in studying these videos. Thanks again!

On a 2 stroke, it is not a good thing to have the engine spinning at max revs on a closed throttle for an extended period of itme. The engine's lubrication comes from the oil that is pre-mixed with the fuel. If the engine is doing 10000 rpms and the throttle is closed and the engine allowed to coast for a prolonged period of time, then the engine's moving parts are not getting the recommeded amount of lubrication that the higher revs require. (Normally, higher revs are only attained with the throttle well open, especially under load, i.e. real world conditions)

On the road, this rarely happens but on a dyno with a 500 kg (1200 lb) rotating drum, this situation can easlily happen. Therefore, after a full speed power run on a dyno, the operator should either apply the dyno brake or pull in the clutch to prevent prolonged coasting on closed throttle.

Was I ever taught this at dynojet 'school' ?. No. All my training with Dynojet was based around 4 strokes. However, a decent mechanic / dyno operator should understand the principles and differences between 2 stroke and 4 stroke engine configurations.

Hope this helps.

Fergus

 

[stay_upright]

+1 if they didn't de-clutch after hitting max rpm and they returned the throttle to idle that's a recipe for a seize.

If it were me i'd ring 'em up, tape the conversation and ask the operator what he does after a run i.e. does he de-clutch or brake the dyno to a full stop very quick but i'd try and do it so not to sound like you're asking him if he doesn't do something that he should - you want an honest answer.

Maybe you can pick out drag torque from the print out or electronic data they gave you of earlier runs - i'm very suspect about them not recording the run where they broke it! (or erasing all data....) . Drag torque may show of they declutched or not.

I don't think cleaning the filter will make the bike run lean, though running out of fuel could be disasterous (and would show up on the dyno run as a sudden loss of power) thugh of course you won't know this as the data *mysteriously* dissappeared. How much fuel was in the quad when you dropped it off/got it back - is the premix oil the same color as you use - i.e. have they filled it them selves to cover something up?

 

[GASGAS300HP]

I scanned the Dyno from the shop!

I hope this helps everyone see the temps recorded and ect..Not sure what they measured if engine temp or coolant? How can I tell from reading this sheet!? Stay upright thanks for your feedback; if you saw the video links I posted on youtube there was no clutch pull that I recall seeing. I left my quad at the shop incase I ran into legal issues. Also their supposed to be looking into my engine and what happened this week. Thanks for your help everyone.

 

[ferguscawley]

The temperature displayed on that graph is ambient temperature (ie - the temparature in the dyno room). This is standard info on the dynojet dynos - they have their own built-in temp and humidity sensors so that the software can use those figures to calculate a correction factor for the hp figure, based upon ambient conditions.

The dyno runs show the quad to be running overly rich. On the dynojet dynos, the air/fuel meter will not register accurately below 10 parts air to 1 part fuel. It is designed to show accurate A/F ratio between 10 and 18 parts air to 1 part fuel. Realistically, when the dyno shows an A/F ratio of 10, then the engine is way too rich at this point.

Do not confuse the term 'rich' with premix ratio. They are 2 totally different things. A bike can be carburating rich (ie too much fuel and not enough air to give a clean efficient burn) but can still cause a seizure if the gas was not mixed with the 2 stroke oil properly to begin with.


My guess is bike was seized due to improper dyno technique and poor cooling (as mentioned in earlier posts) or possibly because of neat petrol being used instead of pre-mixed fuel accidentally.


It will be difficult to prove though. Best of luck.

 

[GASGAS300HP]

No response from Shop since last week,

Fergus, Upright, Hydro, Thumper and all others! Thanks so much for your input on this all. I havent heard from the shop since last week; supposedly their tearing down my quad to see what went wrong some time this week. I believe I'll go by their shop today or call them...Should I be concerned with them trying to hide anything or cover up anything internally?

When rebuilding this engine do I have any options to make it faster or better with different parts?