Temp guage floating By usmarine112 (Read 1,833 times)

[usmarine112]

Hello everyone!! Well I'm back with another problem.. For starters, let me say that I have a 2007 JCL MP250A (linhai version)... My scoot currently has 4500 miles on the speedo and was wondering if anyone has had there engine bogged down after cruising about 70 mph for more than 5 minutes??? I can't figure out what the problem is... My temperature guage is also floating and it never did that before... When I come to a complete stop, it'll stop floating (at least a little) but I'm not sure if it's giving an accurate reading. As I cruise on the highway, the fan is always on so I assume that that is working properly... I just don't know, is the engine bogging down because it's getting worked to hard and starting to overheat or is it something else?? I checked coolant level and it is where its supposed to be. Just recently (200 miles ago) did a valve adjustment and changed the spark plug with a standard NGK DR8EA + an oil change with Mobil 1 synthetic motorcycle oil 10W40... If anyone knows what the problem is please let me know.. My engine doesn't cut off at all it just boggs down after cruising 70 mph+ for more than five minutes... The bogging is getting worse everyday and I'm fearing that soon my engine will just die. I ride my scoot daily to work and the round trip totals 77 miles (all highway). Thanks for the help!!! Hope everyone is doing better than me!!

[ce]

Sounds like you have a loose connection to the temp sending unit, it's on the right side of the engine, kinda below the intake manifold.

And you're losing vacuum to the fuel pump, prolly a loose hose clamp or a cracked hose end. put new fuel and vacuum lines, with new T's or Y's.

You've had enough heat and vibration to loosen a lot of stuff, so check it all out.

[scooteraddict]

My two suggestions are 1) check the connection at the temperature sending unit. You might have to crimp the connection tighter.

2) As far as the bogging, check the float level in the float bowl. My scooter acted the same way when I adjusted my float. When I put it back to the same height as it was, no bogging.

[usmarine112]

Thanks guys for the suggestions... Took a look at all your suggestions and yes there was a loose wire / connector for the temp guage... Was able to take care of that without a problem... The bogging though.... different story.. I checked all the fuel / air lines, float, valves and all in great condition... I have noticed that when it boggs, if I release the throttle and pull it again - the bogging stops for a while... I'm also starting to get low fuel delivery when I begin to take off... Will take off good from start, then lose fuel pressure for a sec then continue strong... Is it possible that the vacuum fuel pump is starting to go bad?? How about changing the oem fuel pump for a Mikuni??? I do still have the OEM vacuum pump installed, could this be the problem?? Thanks for everyone's help!!

[scooteraddict]

if you release the throttle, the carb has enough time to allow the bowl to fill. Once you go back to full throttle, you empty the bowl out to the point that the gas will not keep up. Checking the float just will not work. you must raise the float up one more millimeter. this will keep enough gas in the carb bowl were you would not drop below the jet height.

trust me. i lowered the float height on my carb and it acted the same but only when i was full throttle on hills. after i returned the float to the previous height, no problem.

[usmarine112]

Took apart the carb and cleaned it... Wasn't too dirty at all.. Also checked measurement on float and it was already at 19mm... After putting it all back together, took it for a spin... I cruised a while at 75, longer than normal then it suddenly started again!!! I'm thinking that I'll just change the fuel pump because this is what I've seen others have issues with when it came to losing fuel delivery at high RPM's... It seems that I lose fuel delivery up and down hills... Also, I live in AZ - not too many hills in the valley.... Lots of flat ground.. If I order the Mikuni single fuel pump, is there any adjustment I have to make on it before installing or do I just take it out of packaging and connect it the way the old pump was... Anyone know?? I'm not sure and any help would be appreciated.. Thanks everyone!!! Oh yeah, now that I'm thinking about it.... There is one thing that I changed recently and if I really think about it - my troubles began from that point... I recently replaced the spark plug with one that was originally in the scooter (NGK DR8EA)... However, when I first got the scooter, I replaced the original spark plug and only used (NGK D8EA) - no resistor... So basically, after adding 4,000 miles, I went back to using the original recommended spark plug.. Is it possible, that the change of spark plug could cause this issue??? Just a thought...

[catrell92]

I scoot on a storm 250, everything I know now, I have taught myself lol. I had the EXACT same problem as you, the first thing I would check is an intake leak, I had a really bad leak by my airboxand just sealedit up with silicone, you can usually tell if your bike jumps a lot or has "surges". I was really nervous about removing the crb because I'm new to scoots and didn't want to mess uo anything, I removed the float bow and evrything was good, jets weren't clogged, ect. But what I did notice when I was opening the throttle with the carb out is that this black plunger looking thing in the middle of the carb that had a silver rod going vertically throught it, was stuck. The rod had residue which I cleaned and played around a bit with till it when up and down smoothly. Haven't had a problem since. I'm guessng it has something to do with fuel regulation because my bike would bog a lot for like 5mins then if I kept pulling on the throttle it would run normal, here's a pic if your confused as to what I'm talking about.

[Alleyoop]

From the symptoms my guess is the pump is not able to keep up with the fuel demand. The diaphram in the pump is probably a little weak and not pumping as strong since there is less Vacuum created at higher rpms.
Alleyoop