New guti! Overheating ??

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batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

New guti! Overheating ??

Postby batman » Sat May 21, 2016 2:57 am

Howdy, somehow fortune shined upon me because I'm riding another Malaguti ;-) this one is lc f15 Ben Bostrum. Even better more powerful than the ac f10. Got it last year, ran great.

Too icy cold here in Colorado Rockies for winter riding. Runs a tad slower this season. Runs better first thing and then maybe it's overheating? Just gets slower and slower . . . I will check for air in the cooling system tomorrow. Any other ideas are appreciated. Big thanks in advance!

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Sun May 22, 2016 1:21 am

Did a flush with preston chemical cleaner bc there was some rust in there. Did not change a darn thing.

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Sun May 22, 2016 1:31 am

I probably need to do some work on the transmission? Are there any how to's here describing that?

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Areomyst
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Re: New guti! Overheating ??

Postby Areomyst » Sun May 22, 2016 7:39 am

Congratulations on the Malaguti! They are awesome scooters, as you know.

I don't have any write-ups on the CVT yet unfortunately. Do you know if the scooter has any aftermarket parts? If it gets slower as it heats up I would be inclined to check the compression etc. The last LC Malaguti that I had in the shop had an iron cylinder that rusted in the water jacket, which contaminated the coolant system pretty bad. After rebuilding the water pump and a thorough flushing the system was okay.

If the scooter has any aftermarket parts on it, it could just need to be tuned in better. Maybe it simply needs lighter roller weights or something simple.

~Josh
"The more a man learns, the more he realizes how little he knows."

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Sun May 22, 2016 6:06 pm

Thanks for the response! Should I run a compression check? Hot versus cold?

I just got through taking the malossi variator apart. The six weights were white. One was definitely stuck. Cleaned it out and now dry as a bone with no dust. Three of them had the center pin sticking out a little bit. I gently pressed then back into place with a vice. This is the first one apart for me. Do those pins migrate like that sometimes?

Another funny symptom: sometimes when it runs slow I can get it to catch, so to speak, by letting off the throttle and then grabbing all the throttle I can get.

If I need a new piston what do you think I should get? I would like to get the fastest street scooter around;-)

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Sun May 22, 2016 6:10 pm

I found a trick online for getting that nut off with out the hammer drill. Take out the spark plug and stuff a couple feet of paracord in it's this will stop the piston from moving. Pull it out when done. Seemed to work all right. Obviously leave yourself some slack so you can pull it back out.

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Mon May 23, 2016 9:16 am

And then I'm curious if the main jet on the carb might be funked up?

batman
Posts: 32
Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Mon May 23, 2016 9:32 pm

Compression check cold engine 60 psi
Warm 56psi

So I need help picking out a new cylinder piston kit? Any 70cc ideas? I've been reading all-out;-)

I keep coming across this term called mid race. Could be what I am after because I also want to be able to handle stop and go traffic

Sounds like I need a new crank matched to a 70cc piston matched to a carb and then the right exhaust. I think I have a local motorcycle mechanic who can do the labor for me. Yazuni exhaust seems great until I need a new kick stand? Is there a solid after market stand for these?

If you can help with any info here I would be grateful. I tried to order a belt and filter for the Malaguti f15 last year. Got ripped off twice and waited for a long time to get the right stuff.

After the local mechanic sets up the internal stuff I think I can handle installing the new variator and clutch. But who knows maybe I can haul the scooter to you in nc? Can you mountain tune?

batman
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Joined: Wed Mar 30, 2011 1:45 pm
Location: Glenwood Springs, CO

Re: New guti! Overheating ??

Postby batman » Sun Jul 03, 2016 1:02 pm

Just to be helpful. Any reply is infinitely better than no reply.

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Areomyst
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Re: New guti! Overheating ??

Postby Areomyst » Sun Jul 10, 2016 9:08 am

Sorry batman, I have been very very busy in my daily life and haven't been able to get on the forums much. I've been slugging away at my regular job while trying to do construction work on my shop at the same time... if you're interested in checking that out, see here:
https://www.facebook.com/media/set/?set ... ce5e861084

60 PSI is definitely low compression... As for your questions on a cylinder kit, I don't really recommend a midrace cylinder for a daily driver. It can certainly be done, but I think it's best to start off with an iron sport 70 kit. They are generally more forgiving to tuning mistakes, and can usually be cleaned an honed to near-new condition in the event that you damage the piston due to lean jetting, wrong plug, etc. If you are comfortable with plug chops, jetting, and generally listening/feeling what your engine is doing, then by all means, go with the midrace.

The important thing, is to find out WHY the engine failed in the first place. Otherwise, you could be wasting your time and money, because the new engine build can fail just as quickly if the original problem isn't solved. The rust in your coolant system could be an indicator that the radiator is partially blocked. That could certainly cause a failure... I would flush the system again and verify that the coolant is coming out clean. It is also possible that the rust has damaged the water pump. Make sure to use distilled water when you fill the coolant sytem back up. For coolant, I like to use Dextron coolant as it is made with specific corrosion inhibitors for aluminum engine components... that said, if there's a lot of rust in the system then you have the iron top-end. I guess that's one drawback to an iron cylinder kit! Heh. Anyway, if the engine can run, you can fire it up and let it get warm enough to circulate the coolant. Then feel the coolant hoses (carefully) to ensure that both inlet and outlet hoses are hot. Then you can check for cold spots on the radiator (best done with infrared gun, but you can touch it if you're careful). Cold spots indicate blockage. You can most likely flush the radiator out if that's the case. Radiator flushing is best done with the radiator removed. I used a drill-driven water pump and circulate hot radiator cleaning solvent (available at auto parts stores) through the radiators until the blockage is removed.

Whenever replacing the cylinder, I also like to check the oil pump. The plastic/nylon/whatever gear that drives the oil pump from the crankshaft is prone to failure, but I usually like to remove the oil pump and chuck it into a drill and spin it (counter clockwise) and watch the oil line to make sure that oil is dripping out of the line when you spin the pump. You can skip that step and just pre-mix fuel and oil if it suits you. On a side note, if you go with a big-bore kit, I do definitely recommend going pre-mix. You can mix at 32:1, 40:1, and even 50:1 if you have a high quality oil. I always use 32:1 as it's easy to mix and I've never had trouble with oiling at that ratio...

As far as the Yasuni exhaust, yes, you will loose the center-stand. I am not aware of a replacement centerstand, but I know that you can get a sidestand from Buzzetti for the F12 at least... I assume they have them for the F15 as well. The Yasuni Z and R may not require the center stand to be removed - I don't remember. I know that the C16 DOES require the stand to be removed.

I have built a lot of Minarelli engines over the years and used the stock crankshaft. This was against my recommendation to the owners of the bike, but they didn't want to take the financial plunge to have me install a crank... Some of those engines are still daily driven after years, and a few of them did have conrod bearing failures. It seems the higher RPM and higher power kits wear the cranks faster, for sure...

If you want to put a quick eye on the piston and cylinder, you can remove the exhaust and use a flashlight to look up into the exhaust port. I usually use a mirror as well, so I don't have to get my head underneath the scooter. :) You can easily see the exhaust side of the piston, and the intake side of the cylinder... It's not a perfect way to assess the damage, but it's quick and easy and can give you some insight as to what's up.

I'd write more, but I've got a few things to take care of this morning and I've got to get outta here. :) I hope that the above information is helpful to you!

Kind Regards,

~Josh
"The more a man learns, the more he realizes how little he knows."


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