Starting problem P200E - Very strange

I have got a Polini 208 engine, which is newly rebored so the cylinder and piston are as new.

Cylinder Polossi W5 cylinder with new type 2 ring Polini piston, cylinder head MMW Polini 208 type.

New SitoPlus Exhaust.

I use a 24/24E carb with DRT float mechanism , 2mm outlet and a 3mm DRT float chamber spacer.

Jetting is 65/100 starter jet, 180 air jet, BE3 , 128 main, 48/160 slow running jet - P200E airfilter with 4mm holes above the jet stacks.

It has 18 degree timing ( I have also tried 19 - 21 degree with no difference), B7ES plug , Ducati CDi.

 

Heres the problem:-

It starts from cold and drives really well, pulling hard in all gears - no nasty noises etc.

But even after just 5 mins , if I switch her off she is a nightmare to restart. I have checked for fuel supply and electrical problems but everything seems to check out. I am beginning to suspect a fractured casing maybe , but really am starting to guess.

Any suggestions guys ? I use the scooter for work transport as well as fun so its really important to get some relaibility.

 

 

 

 

 

 

 

Hi!

Might consider changing plug as well.

 

7 is maybe to cold? -try 8 or even 9.

 

Do some plug-checks and see what is best.

Hi

 

Sounds interesting !

Do you have a link ?

 

 

cheers

[quote user="Hamer"]

Is it this?

http://cgi.ebay.co.uk/Extreme-High-Temperature-Carbon-Black-Exhaust-Paint_W0QQitemZ120539708961QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item1c10b9fe21

 

Yes, thats the stuff ! Excellent so far in my opinion.

 

[quote user="hannes"]

does every cilinder need a paint job or is it just for that kind of cilinder?

i would think that an un-painted cilinder would transfer the heat quicker that a painted one?

 

thanks, hannes.

[/quote]

 

I always paint the cylinder and head flat black, it dissipates the heat much more efficiently.

 

[/quote]

Nice idea, i'll paint my cylinder and head too [:)]

Svint - the  B7ES is one grade colder than standard , so an 8 or 9 would be colder again. NGK numbers run low to high / hot to cold - 6 is hotttest and they burn cooler from there on.

Congratulations [:D]

 

What paint do you used for the cylinder, something special ?

 

 

 

cheers

Keep us posted as to how the scooter is going. I want to set up a Polini based engine and use it for long distances every day. How much case modification did you apply? Are you using reed valve intake?

Is it this?

http://cgi.ebay.co.uk/Extreme-High-Temperature-Carbon-Black-Exhaust-Paint_W0QQitemZ120539708961QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item1c10b9fe21

 

Yes, thats the stuff ! Excellent so far in my opinion.

 

[quote user="hannes"]

does every cilinder need a paint job or is it just for that kind of cilinder?

i would think that an un-painted cilinder would transfer the heat quicker that a painted one?

 

thanks, hannes.

[/quote]

 

I always paint the cylinder and head flat black, it dissipates the heat much more efficiently.

 

Fixed ! . . . . I think  . . . . . I hope !

 

The carb was the original 1977 Del'Lorto, the body had a series of fine cracks running thru it - I changed it for another Italian body and everything seems to work fine. Really disappointed to lose the original carb, it only lasted 33 years !! [;)]

I used a special liquid paint from a UK Classic Bike specialist, its applied by sponge and cures harder as more heat is applied. So the hotter it gets the longer it lasts, the exact opposite of standard style heat paints.

They sell on eBay at £10GBP for a very small bottle, very small but enough to fully coat the sitoplus at least 8 times !

Is it this?

[url]http://cgi.ebay.co.uk/Extreme-High-Temperature-Carbon-Black-Exhaust-Paint_W0QQitemZ120539708961QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item1c10b9fe21[/url]

does every cilinder need a paint job or is it just for that kind of cilinder?

i would think that an un-painted cilinder would transfer the heat quicker that a painted one?

 

thanks, hannes.

The scooter seems A1 now , maybe running a little rich but a dyno check soon will correct that. Its running with rotary valve standard induction and all seems good. Loads of torque and enough rev out ( due to the Worb 5 porting) to give me a really good top end flexibility also. I have to be carefull as the rebore is still quite new but it smoothly and quickly reaches 80+ kmh at about half throttle. I have changed the plug to B8ES with 0.5mm gap , and painted the cylinder with black engine paint.

All feels perfect at the moment.