Howitt 150cc GY6

[rocko]

Hey , I am a new member and live just north of New Orleans and I have a Crossfire 150R that I got from a neighbor for a good price but it's starting to be a money pit , it was used very little as it still had the little rubber tits on the tires but set up for 3 or 4 years ---------------the problem I am having from the get go is it feels like a rev limiter sets in about 3/4 throttle and the engine don't rev up and won't take the gas , the carb was cleaned 5 times then a new carb was bought off the net and a 128 jet installed in it because I changed the air cleaner set up , replaced the intake manifold , the coil , and have had 3 different CDI 's on it , the last one being a no rev limit one , replaced the piston and cylinder and compression is at 155 psi , set the valves numerous times and have the timing right on and it still does the same thing it sounds and runs perfect till you get the rpm's up to between 1/2 and full throttle then it like shuts down ------------- any ideas that I may have missed

[ckau]

there may be nothing wrong. you possibly could be running out of gear.Whats the top speed you can achive? any idea of the max rpm's you can turn? have you checked the throttle cable adjustment to insure your completely opening the carb?

[rocko]

Thanks for the reply ---I don't know my top speed , no speedometer , I have a hand held GPS but never did try to see the speed , I'd guess 15 -20 mph ----------but that isn't it as when you get to about 3/4 throttle the motor like shuts down and doesn't produce any power and starts sputtering and spitting and you start slowing down , when you let your foot off the throttle it will fire back up and start running again , it really seems like a rev limiter but I have tried 2 no limit CDI's on it with the same exact results

[jetboy300]

Have you increased the fuel line size? Just a thought, you might not be getting enough gas. Also check fuel filter for restriction.

[metalstudman1]

I agree with Jetboy300-this sounds like a fuel delivery issue. Replace the fuel lines with 1/4" clear ones (cheap @ hardware store),verify fuel filter is clear and check the tank for something/trash blocking the outlet.

[rocko]

No I have not changed the fuel line diameter , and I will try that this weekend , I am going to flush the tank while I am at it and fill it up with premium fuel as I was burning regular and was told by a few people the GY6 runs better on good fuel ---------- I want to pull the flywheel this weekend and check the key way , but doubt that it sheered as the timing marks are right on , don't think it's the stator or trigger and it's always the same 3/4 throttle shut down ------------the GY6 had this same problem since I got it , I thought for sure it was the carb , it is a new carb on it now , new coil new intake elbow , 155 compression on new piston , cylinder jug and rings rejeted the carb to 128 ( I am at sea level ) , new air cleaner ( ran it with and without aircleaner , original and after market all the same results , new choke coil and checked it sevseral times but really don't like it I read where someone replaced it with a primer rubber button but lost the thread -----------seems I read somewhere that a kill switch or igintion switch will do whats going on with me but have not tried to by pass it yet ---------------what ever it is thats wrong nothing I have done so far has any effect on the problem , it always acts and sounds exactly the same ----------- thanks for the reply , Don

[metalstudman1]

Well the tank and fuel lines are as they were when you got it right?!!!! Maybe you'll have a CHEAP fix!!!!!

[GX150]

In addition to fuel lines, check the petcock for good flow and the gas cap for venting.

[rocko]

Cleaned tank and petcock , changed fuel filter , new fuel lines and fresh premium gas and still have the same issue ----------it is really crazy as you turn the key and it fires right up and after a couple of minutes , I'd guess after the choke warms up it drops some rpm's and runs just as smooth as can be , lots of power till rpm's get up to a little more than half way and then it drops out , let your foot off the throttle and rest it below 1/2 throttle and it runs great ----------------------do you'll think a stator , the trigger or the voltage regulator will malfuntion at high rpm's and not at lower rpm's cause thats about the only parts I have not changed yet

[SYCARMS]

Have you checked the cvt out yet?

TOM

[SYCARMS]

Also since it has set up that long mice and dirt dobbers love making the exhaust home. A restricted exhaust will surely cause your problem. The pickup will either work or not work. Stator is a possibility if it pops at high rpm.

TOM

[rocko]

What is the CTV , not sure on that one ---------

[SYCARMS]

The cvt (constant velosity transmission) is under the cover on left side if engine and consists of the drive belt, clutch, and variator. There could be flats on the rollers keeping them from rolling all the way up the ramps. Weak or broken torque spring.

TOM

[rocko]

Had a 4 day weekend and didn't get to spend any time on the cart as a tropical dpression moved through the area and it rained 15 inches of rain in 4 days straight ------------- I really don't think it is a transmission related problem as it seems to be more electrical shut down or maybe fuel starvation , but who knows ----------I have a new no limit CDI on the way and hope to get it this week and give that a try

[ckau]

while your waiting on that new cdi.. you can improve the electrical system and possibly solve some issues by simply running a ground jumper. The negitive lead from the battery is normaly run up and connected under the metal plate that all the electrical stuff, cdi, starter solonoid and the wiring connections are mounted to. As the system is in stock configuration, the motor recieves ground through the motor mounts! not real dependable. Run a jumper from the negitive connection point to one of the starter bolts. this will insure the starter a good ground for cranking and give the motor block a solid connection for the coil. Then replace that cheap p.o.s. on/off switch with something of better quality. that switch is notorious for giving problems.

[rocko]

Thats some good ideas that I will try , I had read somewhere that the on/off switch could be a problem by never presued it ======= did alot of work to it , need to get a fresher pic , something I have done was to widen the wheel base back and front by flipping the front and back rims around and adding 2 inch spacers to the rear , on the front I had to drill another hole and move the valve stem to the outside as it hit the caliper ,to fill the existing hole on the inside the rim I used a valve stem that you can unscrew the stem out of it and put a plug into the threads that the stem was screwed in making it flush , after flipping the rims Cragar hub caps worked , I added a rack on the front to hold a 12 pack coller and gear , a top off an EGO golf cart , a rear view mirror , custom air cleaner with mounts and inlet hose , coil , carb , CDI , piston , rings , jug , lapped the valves , custom tail light assembly ----------------- I have been dreaming of moving the seat , steering and controlls to the middle and making it a one seater and been looking for a good bike engine like a 350cc or up water cooled and using a gas golf cart rear axle I have which has reverse to drive the wheels

[SYCARMS]

Instead of the ign switch, replace with waterproof toggles one double throw for the ignition and a momentary for start. If someone wants to steal it they generally won't need the key's since they will just push it up on to a trailer. If your concerned about someone just jumping in it to drive without permission you can add a hidden toggle to cut power to the main switches. Now you don't have to worry if you get to your place to ride and forgot your keys and these switches will last a lifetime. They won't be cheap $15.00 and $19.00 but well worth it. These are available thru Summit and Jegs.

TOM

[GX150]

Marine supply stores also have nice sealed switches.

[rich1]

This problem really sounds like a stator going bad.

[SYCARMS]

Could be a stator, however seems lately I am getting equiptment in my shop somebody found a great deal on but it either don't run or runs poorly.I have worked on 2 buggies and 1 2 cycle atv which had no top end at all. The buggies had the same problem for they would idle fine and even ran well at low throttle but put the pedal to the metal and they would fall on their butt. One turned out to have massive dobber nests in the muffler the other had a rats nest in the muffler. The 2 cycle would not run at all with exhaust attached it also was plugged with dobber nests. These had all sat up for a couple years in some out building. All you have to do is loosen the exhaust at the head and try to accelorate, if it runs you know the muffler is plugged. Easy and takes no time to check.

TOM

[rocko]

I know the exhaust is ok , first reason was that the exhaust broke all the way off at the flange while riding it a while back , I had to run it home with no exhaust for about a mile and it still did it , had my buddy heli-arc it back together and ordered a new exhaust , put the welded one back on till the new one came in , then installed the new exhaust and it still did it , I probally should have left the welded one on as it is probally a lot stronger than the OEM part as when he welded it he put three little triangle gusits from the flange to the pipe -------------I am thinking the stator also as it is about the only part I have yet to mess with ---------------I have not got to mess with the cart now for a while as we had a storm two weekends ago and last weekend I started another project for work that is going to tie me up for a few weekends ----------the no limit CDI came in and is sitting on the desk here but I have not tried it yet , really don't think this is going to make a difference ------------ whats really crazy about this problem is it runs so good till you hit the 5/8's max rpm mark , low speed power is there , idles and starts like a clock , I'd like to hook up some kind of tack to see what rpm's it falls out at

[edroden]

I was thinking, to eliminate the RPM limit idea from the equation, take the chain off and rev it up and see if it still cuts out at the same rpm range.

It really does sound like it's starving for fuel at high rpms.
If it is starving for fuel, it should rev pretty high before it starts to die, since it won't be pulling any load.

[the_law_man01]

If you check the stator and it's fine, I am still running stock fuel line on my Yerf 3206 GY6 just fine, but my brother has a Schwinn scooter with the GY6 150cc on it. It has an inline fuel pump that is ran off of a vacuum hose just below the fuel tank. I'm guessing that it is because the motor will be ran at higher RPMs for longer duration while on the highway?

Anyway, I think the scooter also comes stock with an 8 pole stator and I thought I read on Buggy Depot that the GY6 on the buggies has a 6 pole. Not really sure as I'm new to all this, but I made these observations in the last couple days.

If you wind up needing a fuel pump for it, all the engine parts from that scooter seem like they will work on my buggy. Same engine, different application.

Hope you can get it figured out.

Joe

[GX150]

1. That is most likely a vacuum operated petcock on the scooter unless the tank sits lower than the carburetor.

2. Depending on buggy or scooter, the GY6 engine may have come with a 6-pole or 8-pole stator. There is no way to really tell unless you pull the flywheel. These are easily changed, but you must have a matching flywheel for your stator to work properly.

3. Gravity feed is sufficient to get fuel to the carburetor, but many vehicles have restrictive petcocks, filters and lines. Replacing the hardware and upgrading to 1/4" line will help flow. The tank also has a breather vent typically in the fuel cap. if this vent is clogged, it will cause poor fuel flow.

[SYCARMS]

Good point GX150 made about checking the fuel cap for venting. Not sure of the crossfire but the ASW buggies have an issue with the ethanol in fuel reacting with the plastic of the fuel cap. On several ASW buggies and just a handfull of Kinroads the fuel caps due to the ethanol content seemed to melt the insides if the cap blocking off any ventilation of the fuel tank.If totally blocked you will run until engine runs out of fuel then after 5 minutes or so it will start again and run, but if restricted it will act as if it is running out of fuel at high speeds but run fine at idle and lower throttle speeds. It blocks it enough slowing the rate of fuel.

TOM

[rocko]

Thanks for all the tips ----------- I have the Crossfire 150 R , the tank is above the engine with a petcock on the bottom so it doesn't have the fuel pump , it has a cap made of hard plastic with a vent hole , the hole is clear and I have run it before with the cap loose to see if it was a vacumm problem , I got a boat and been bite with that one before , there is a really good clean gravity flow of fuel when I let it flow into a clean container --------- I did a little bit of readiing on the different number of pole stators and have not had a chance to take the flywheel off yet to see whats in there ---------------I was wondering if the problem could be in the choke , I have tested it several times with a ruler and the measurement come out right on , and have tried a couple of different choke coils with the same results , but still wonder as I am not a fan of the electric choke set up , I had read some where that someone had replaced the electric choke with a primer bulb with good results , finding the right part seems hard ------

[SYCARMS]

if you cheched the choke and it checks fine then it's fine. A bad choke will make you run rich and not lean.

Tom