Morini doesn't cruise smoothly

GoldenMotor.com

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
I recently acquired a boxer frame with a Morini. If it's the 6 or 9 hp I have yet to find out, either way it's more than enough power, it's scary fast.

Well anyway I was riding around with fatdaddy and also discussing a group ride for the summer.

This is first time I tried to go cruising in the on the street, I noticed that when I tried to maintain a nice cruising speed it wouldn't maintain a constant speed.

It will pull hard for second, and then slow down for a second, and accelerate

Idk how else to explain it, hope it's so that the experts understand my questions.
 

Goat Herder

Gutter Rider
Apr 28, 2008
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Fuel flow problem? This happening at lower speed or a higher speed. Here is a link about the fuel flow if it helps? http://motorbicycling.com/showthread.php?t=24880.. On my goped tank I had two problems.

The stock fuel petcock that my machine came with , The rubber parts in the valve distorted enough to hamper my fuel flow. I still have not sourced a new petcock. As everything I found was not attractive looking and difficult to mount to the bike frame. I actually used a white bic pin sleeve to join my tubing. Ends pulled of it. Necessity being the mother of invention never had to do anything with it after that. My carb has never ever over flowed . The valve in it is way better than any typical H.T. Carby

As for fuel flow at my Goped tank I made ''very small'' discrete holes at the under side of my gas cap. Solved that problem for mine when I had it.
 
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ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
It's more like in the mid range.
But I'm also bogging a little at the top end. I need to do a plug reading and lean out my fuel mixture, I think I'm running at 40:1 non synthetic

I'm either puttering along at 10mph or I'm full acceleration till I top off... Doesn't like to do mid range crusing.

I'm gonna follow your advice about the fuel problem along with checking my oil bath/clutch shoes and replacing it with belray 80w I believe.

I'm not quite sure but does the carb have fuel to air ratio adjustments?

... The bike has quite a few kinks that I need work out, bit man is full suspension a blast to ride, I don't think I ever wanna go to non suspension china girl lol
 

Goat Herder

Gutter Rider
Apr 28, 2008
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If you have the 19mm PHBG carb it is supposed to bog a tad at full throttle . That is your safety zone at red line as that carb lets a lot of flow through it! The Air/Fuel mix has to be properly charmed.. . ''very important'' So you do not burn your motor up. The generic term I have heard it by is tuning for altitude. You are going to reach your top RPM' s and have all the power you need when tuned this way.


This is how the PHBG tuning tutorials I read ALL said to do it....

When I am just getting into a hill or aggressive hole shotting from a stop the added richness helps me with needed extra power nicely . When getting to full RPM I simply back the throttle off just a tad and the motor just does that so00 beautiful song and hum!:) At this stage of established acceleration if I do not slightly back off from full throttle the bike mine will stumble. These are racing motors and the tutorial on the PHBG carb from moped army even says to tune this carb this way!;)

http://www.mopedarmy.com/wiki/How_To_Tune_PHBG_Carburetors

I have tuned it by way of main jet before to see if I could more speed. It is not worth it and you do not magically get more speed with this PHBG model carb..


You are at sea level so really doubt you need to reject your carb? All carbs come generically jetted for sea level.. I also don't know what all these carbs are coming with jet wise stoke, and have never run at sea level?

Think 90 main jet Mebbe at second needle notch? 50 pilot a W9 needle with a 262 AU atomizer and a 60 choke jet for stock sea level... ??? No body ever say's what they are using on a 19mm PHBG??



This full throttle deal only happens for me after full acceleration and the motor is not seeing that load of acceleration. Humming along a full speed. Liken to 4 stroking..

There is a static idle adjustment and then a fuel adjustment screw on your carb. The fuel adjustment screw represents the first half roughly.. 1/3 of the lower throttle dynamic. Put a hotter plug in it to. I run a NGK B8EGV Stock is a 10 on the S6S engine..

Have had the recent opportunity to to work on a lot of 2 stroke trimmers and chainsaws lately. Tuning them for altitude is the same way I have been taught . On those particular carbs they had a high side and a low side adjustment. I set the high side to where the motor sings it's best at wot then go a turn back and set it richer. ''Safety Zone!''
 
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ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
Hmm, information sounds very helpful but I'm lacking some experience and mechanical lingo to fully comprehend.
Or maybe it's just to late... I'll look at it again tomm, I'm gonna be doing a couple things like changing the plug, sealing my exaust manifold with high temp silicone sealer ( bit of leak), my fuel flow issues, clutch oil, and tightened up my rear spokes.
The spoke like to get loose in the back rim, second time I will have to retightened them.

Sounds like a busy day tomm and not much riding lol :-||
 

Goat Herder

Gutter Rider
Apr 28, 2008
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How does the O ring on your manifold look? Mine actually has never leaked. Careful not to over do the RTV. That stuff in excess will wind up in the motor at the exhaust port. Where it will turn to a hard carbon before it digests.

I get some exhaust residue in that area. 2 stroke mix. I always wipe the bike down after couple rides and has never been bad for me that way..

The new custom wheel I built over the winter has never come loose. Something was weird with my first rear wheel and rim combo ? I had to maintain the spokes. It worked good for me but in the end my new spoked rim combo has been perfect. Built the wheel and never touched it again yet so far. Spokes look as tight as day one.
 

ocho ninja

Member
Jan 14, 2012
564
2
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San Jose, CA
It looks okay but it is split at point.
Also do u know what the torque for the spark plug should be, I have a bit of blow by coming out.

Yea my rear wheel is weird. I'm thinking of re tightening the spokes and then putting a small amount of locktite to keep their
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
Thais for the site and info
Were can I get some replacement gaskets?
Checked my plug, its lighter brown, not real choclately ( starting to crave to chocolate fudge cake lol)

Replaced it with NGK, showed my stock one at the auto parts store and the pretty lady cross referenced it

Fixed my slight leak with some epoxy

Used some of the rtv on the outer edge of the exaust, hopefully it doesn't go inside

Checked my fuel petcock, I'm gonna drill some small holes to get better venting also

Still need to change my clutch fluid and give a run... Went to the auto parts store and was a little unsure of which oil will work for my clutch, confused about the multiple oil weighs and viscosities.
 

Goat Herder

Gutter Rider
Apr 28, 2008
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Get Maxima MTL or Belray wet clutch fluid. In light of my own recent experimenting with motor oils etc. I will stay with Max 85 wt . Not sure what others are using? I will no longer experiment with oil again myself.. Gonna have to go to a motorcycle shop to get it... My plug is actually light tanish in color with my D.H... Scares me a little but it has been has run fine for ever now. My own observations of how the motor loads up at a prolonged idle I just mix up how I throttle mine a little and I know I am oiling.

To go clear across town redlined and not mix my throttle positions up a little kinda goes against my nature of thinking. Got my carby currently on the cutting edge of safe lol. Have not had a single problemy yet.

Why do you need gasket paper? I have reused my original clutch gasket for ever now. Can get gasket paper at the automotive supply you will have to take your time and cut out a new gasket from scratch. Order a gasket set from Herdan . I have never had to fix any kind of leaks with epoxy ether. What the heck is that on?
 
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ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
Yea I found a shop near my work that deals bel ray oil, gonna drop by tomm

... Yea I don't drive flat out all the time, just get to a certain point and let off.
By any chance do you know the max revs on these motors. I'm gonna install a tach tomorrow also.

What is this safety zone you talk about, how do u adjust that on the carb?

I fixed a small leak on my gas tank, it was big enough to let of a drop every other min

I was talking about the rubber like o ring on the exhaust, do you where I can find those?
 

Goat Herder

Gutter Rider
Apr 28, 2008
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I never did find a O ring I liked my exhaust leaked on my first motor until I got the right one from Herdan. Got me a bunch of spare ones last go around that I have not needed yet. To understand the safety zone just read the carb tutorial at the moped army link.

You never said what carb you had?
 
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ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
I look at the carb tommorow. I let you know
Also posted some more pics of what I got.

And by any chance for how much would you send me o rings?
 

ocho ninja

Member
Jan 14, 2012
564
2
16
San Jose, CA
I looked trough his website, didn't see anything for th o rings.

I finally looked at my carb and the only numbers I saw was deloroto SHA 1412L

What does that tell you about my motor, any tunning tips?
 

DFlanagan

New Member
May 23, 2011
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0
Colorado Springs, CO
Yea I found a shop near my work that deals bel ray oil, gonna drop by tomm

... Yea I don't drive flat out all the time, just get to a certain point and let off.
By any chance do you know the max revs on these motors. I'm gonna install a tach tomorrow also.

What is this safety zone you talk about, how do u adjust that on the carb?

I fixed a small leak on my gas tank, it was big enough to let of a drop every other min

I was talking about the rubber like o ring on the exhaust, do you where I can find those?
I have to chime in here. If you have a ACE Hardware store around you, that is the place to get your exhaust O rings and kickstart shaft O ring. That's where I got my replacements from. They have a huge selection. Standard and Metric.
 
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Old Reliable

New Member
Feb 21, 2012
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Santa Ana
Goat herder, I respect your knowledge of small two stroke engines. You always have good advice. Ive done two rebuilds on my s6c. The engine runs great until I hit max rpm, and it tends to be sluggish at the top end. Ive already replaced the crank hakves gasket, so I doubt I have a leak there. The bike used to scream at 70, now struggles at 60 and strikes fear at seizing the piston. . Do you have any advice on what could be a solution to this problem?