dies at WOT... thoughts needed

[minimotos95]

if i go WOT for a mile or more my spree will die and i can't start it unless it sits for a few minutes and the first time it backfired(or the opposite)... i have 2 thoughts that it could be...
1. a clog somewhere in the fuel supply that doesn't allow enough fuel through to go WOT and it runs the bowl dry... i can't think how that would cause the backfire though
or
2 it's running extremely rich at WOT and floods.... but it doesn't blow blackish smoke just blue(and only when cold) and if it was running that rich the plug would have fouled already

it runs fine cruising at 3/4 throttle but not WFO
anything else that could cause this before i go tearing the scooter apart?

EDIT
of course i have a VM20 sitting in the garage i have been wanting to put on something which i might do along with a dual tank set up just for the extra range and so i know it's not starving the carb. which could solve all the problems unless it's somehow ignition related...
hmm i guess i should pull the plastics off tonight and read the plug

[Bear45-70]

Sounds more like it is running lean and soft seizing.

[minimotos95]

possible
wow, i pulled the plastic/fairing off, the carb is covered in gunk... open up the airbox and see no filter... i took an old torn filter from my 144 and put it in there going to take it for a spin and get a new plug on my lunch break tomorrow
i pulled the plug and it's red? which according to my research is usually due to it running to hot or it's additives... not very normal but then again i and the PO were running normal aircooled premix in it not the redline i run in my 144



i don't know about soft seizing i have never even heard of it until now, if it was doing that there would be a noticeable compression drop wouldn't there? my first thought when it did it was that it blew the top end but when i reached down and turned the flywheel it still had great compression.

[Bear45-70]

The Spree is "OIL INJECTED" and you run straight gas in the gas tank and injection 2 stroke oil in the oil tank, NOT pre-mix.

[minimotos95]

what's the difference between oils sold as "injector oil" and as ones sold as "premix"? viscosity seems the same and lubrication difference is minimal if any. so to me no mater what it goes in it's called premix oil even if it goes in an oil injected bike like the spree or a ke100.

all forms of 2 cycle oil = premix even if it goes in a tank instead of pre mixed with the fuel... it could be a regional thing though.

now back on topic, thoughts on the red plug? it's more red then the picture looks

[Bear45-70]

what's the difference between oils sold as "injector oil" and as ones sold as "premix"? viscosity seems the same and lubrication difference is minimal if any. so to me no mater what it goes in it's called premix oil even if it goes in an oil injected bike like the spree or a ke100.

all forms of 2 cycle oil = premix even if it goes in a tank instead of pre mixed with the fuel... it could be a regional thing though.

now back on topic, thoughts on the red plug? it's more red then the picture looks

You would be wrong in your oil theory, but hey do whatever you think is best.

The red plug is caused by the brand of gas and oil that has been used. A red pug is not a sign of overheating.

[abreen89]

what's the difference between oils sold as "injector oil" and as ones sold as "premix"? viscosity seems the same and lubrication difference is minimal if any. so to me no mater what it goes in it's called premix oil even if it goes in an oil injected bike like the spree or a ke100.

all forms of 2 cycle oil = premix even if it goes in a tank instead of pre mixed with the fuel... it could be a regional thing though.

now back on topic, thoughts on the red plug? it's more red then the picture looks

just use a good injector oil BECAUSE ITS BEING INJECTED.. is probably the best answer for why......... i like the GN2 injector oil that i get at my honda dealer for 6$ a quart. and then just run normal gas in the tank. also you not having an airfilter could have been the cause for the soft seize. I would check compression (with a compression tester) just to be safe. When you get your spark plug if you havent already dont settle for an autolite get ngk they just plain work better and longer.

[minimotos95]

hmm i just looked up my favorite oil and saw this

This Red Line two-cycle racing oil provides improved power and perfect cleanliness. Power improvements of 3 to 5 percent have been obtained in dyno tests. Its high-temperature stability prevents deposits in even the hottest upper ring and piston crown areas. Two-cycle racing oil is suggested for use at 50:1, but can be used richer or leaner, up to 100:1, depending on the type of engine and its operating conditions. It provides unequaled protection in motorcycles and marine engines as premix or injection oil

i guess i will order a gallon when i pick up my irc mb38s
if i was going to buy specifically "injection oil" it would be redline snow/marine or PJ1 silverfire
yes i do run normal low octane(85) gas in the tank then i have some junk ace brand air cooled oil in the oil tank

right now it has some champion plug from the PO, all i ever buy is NGK.

i'll see how the test ride goes tomorrow i can do a compression test after i put my new tires on(ordered monday from parts unlimited so they should be here soon)

[breaze]

hmm i just looked up my favorite oil and saw this

This Red Line two-cycle racing oil provides improved power and perfect cleanliness. Power improvements of 3 to 5 percent have been obtained in dyno tests. Its high-temperature stability prevents deposits in even the hottest upper ring and piston crown areas. Two-cycle racing oil is suggested for use at 50:1, but can be used richer or leaner, up to 100:1, depending on the type of engine and its operating conditions. It provides unequaled protection in motorcycles and marine engines as premix or injection oil

i guess i will order a gallon when i pick up my irc mb38s
if i was going to buy specifically "injection oil" it would be redline snow/marine or PJ1 silverfire
yes i do run normal low octane(85) gas in the tank then i have some junk ace brand air cooled oil in the oil tank

right now it has some champion plug from the PO, all i ever buy is NGK.

i'll see how the test ride goes tomorrow i can do a compression test after i put my new tires on(ordered monday from parts unlimited so they should be here soon)

Don't see PJ1 Silverfire mentioned in here often - I use it simply because that is what my local cycle shop carries - almost no smoke or odor - seems to be good stuff.

If you were runing without a filter, seems like that would back up what Bear is saying about running lean and may be your main problem. However, seems like you may have other things which should be of concern. Why would you run a cheap non-injection oil thru the pump (by putting it in the oil tank) when Honda and everyone on this forum suggest only 2-stroke injector oil? Along with a new air filter and plug, you should probably switch that out and check the operation of your pump. You mentioned that you were putting cheap 'ACE' brand oil in the tank - are you also pre-mixing with the fuel in the fuel tank? You may be right that once the oil reaches the crank-case, it is all "pre-mix", but it has to reach the crank-case by going thru the pump - I believe this is where the injector type oil is necessary so that the pump is not clogged up and remains operational.

Good luck

[abreen89]

hmm i just looked up my favorite oil and saw this

This Red Line two-cycle racing oil provides improved power and perfect cleanliness. Power improvements of 3 to 5 percent have been obtained in dyno tests. Its high-temperature stability prevents deposits in even the hottest upper ring and piston crown areas. Two-cycle racing oil is suggested for use at 50:1, but can be used richer or leaner, up to 100:1, depending on the type of engine and its operating conditions. It provides unequaled protection in motorcycles and marine engines as premix or injection oil

i guess i will order a gallon when i pick up my irc mb38s
if i was going to buy specifically "injection oil" it would be redline snow/marine or PJ1 silverfire
yes i do run normal low octane(85) gas in the tank then i have some junk ace brand air cooled oil in the oil tank

right now it has some champion plug from the PO, all i ever buy is NGK.

i'll see how the test ride goes tomorrow i can do a compression test after i put my new tires on(ordered monday from parts unlimited so they should be here soon)

Cheap ace brand oil????? you might as well run the cheap gas with water in it too. If your going to buy something and expect it to run right and last a long time you need to atleast put the propper fuels and oils in it. These arent 4 strokes that you can throw anything at.. theses are high performance 2 strokes and without the proper oil and fuel you will have a chance to test it again with the proper variables in place. Oh and btw you can check engine compression without tires being mounted.

[SuprasNsprees]

Don't see PJ1 Silverfire mentioned in here often - - almost no smoke or odor -

I LOVE the smoke/smell! especially when you have a tank of hot fuel


i also use the GN2 (600+ HARD miles on my build with LONNG WOT pulls)
sometimes use the Lucas when in a pinch


dont sweat the "gunk" ON the carb. its purely cosmetic

[minimotos95]

High performance? Stock It's low revving low compression air cooled engine ported for fuel economy that tops out at 30... the gunk on the carb and lack of an airfilter tells me the PO had no clue what he was doing... my lunch is 2 hours I will let you know how the test ride goes... IMO pj1 and redline are the top oil brands they both have minimal smoke and little residue

[Trafficjamz]

The gas tanks get pretty rusty on these little scooters.

There is a filter inside the tank that gets clogged and cant supply enough gas to the carb bowl.

Make sure the air box filter and lid are in place, or else it will bog at WOT from a too lean mixture.

These little engines are very sensitive to intake / exhaust changes

[Trafficjamz]

You must make sure that the oil you choose is rated for air cooled engines.

Air cooled engines run at much higher temps than H20 cooled ones.

And if you are using the stock injection system, you must make sure the oil is designed for injection and not for premixing.

[minimotos95]

going by that i really need redline all sport, designed for air cooled. premix or injected

wasn't able to get more plugs but i ran it up and down the street, no problems. 27mph now

and yes i have to wait until i get my tires to compression test it and start DDing the NQ instead of my 240sx. because i have to have my tools at work and at home with me until i get the tires

I'll work on it more when i get home