Strada RX150 Won't go over 25mph!

[haveahotcarl]

Long time reader, first time poster. So please no flamage!

I have a 2005 Yamati Strada RX150CE with just under 1000 miles on it everything is stock. Recently i found that it won't go over 25-30 mph. It starts fine and idles without a problem but seems to bog out and have no power after hitting 25. It seems to be that I am running lean, but the plug has no white deposits.

I talked to a local Strada "dealer" and he suggested the auto fuel shut off. Replaced that, still sucks. Adjusted air/fuel, still nothing.

I also noticed that it is getting very hot very quickly. When i first noticed the problem the exhaust was hot enough to burn the rubber mounts and cause smoking. I opened the filter to find that there was some oil in the air box where the "breather" tube came in off of the head.

I am not the biggest expert on small engines so any help is appreciated. I am willing to do almost anything to the motor and am very mechanically minded.

Thanks!

[burnt_toast]

Definitely sounds like you're running lean somewhere. If everything else is stock, check for leaks somewhere in the intake tract, before and after carb. also pull plug and inspect, if its white or light colored that means its lean.

[EngineerBoo]

Yea, running hot can mean it's too lean.

Did you check the fuel lines for any clogs or the fuel filter? (That'd prevent the engine from sucking in more fuel to go faster.)

I had a small engine that would only run on low rpm's and I found some slime in the fuel lines because of a little gas that had been left in over the winter.

Good luck!

[haveahotcarl]

I'll try that. I thought it might be a clogged line. Any suggestions on the best way to clean the fuel lines? Would a good shot from the air compressor do it? or is there a cleaner that could help?

[burnt_toast]

I'll try that. I thought it might be a clogged line. Any suggestions on the best way to clean the fuel lines? Would a good shot from the air compressor do it? or is there a cleaner that could help?

why not just get new ones? its just standard fuel line you can get from most auto places, just take an old line off and match it up.

[haveahotcarl]

Alright, I got it running and seems to not be bogging out. I can still only get up to about 45. I was able to go much faster before and get there quicker. I also have the air/fuel higher than where it started. Any lower and it doesn't run well and bogs out.

I took the carb off and blew out all of the passages. I pulled the plug, cleaned it and checked the color after a short test run. It didn't show anything out of the ordinary, nothing light/white. I also re-gaped the spark plug to .024"<--seemed to do the most good. I checked the fuel filter as well and no flow issues there.

Maybe I am just beating the dead horse and I can't go any faster. I would really like to get the ~55mph that i had gotten before and of course get some ridiculous acceleration. I am also open to any mods that might help. New jets? air filter? all new carb?

[chubbyrockstar]

Have you tried removing the bottom carb bowl and rmeoving the jet and sprayer to clean them out?
could be just a small deposit not allowing enough fuel in.

I use a guitar string to clear my jet and sprayer every couple months on my Yamati Strada Rx150


this might sound a little stupid but perhaps your seat tub is crimping the fuel line? mines pretty close down there.

Any Fins on the fan broken?
Sounds like some friction going on, could be a plugged oil filter?