RD350F tricky to start

[Andy J]

So, the RD that I bought in August has a niggly little fault. If left for a few days it's a bugger to start. It needs multiple kicks to get it fired up, sometimes taking a minute or two of kicking. Once running however it will play nice all day, starting first or second kick every time. It will even start ok the following morning. But leave it a few days and it's back to square one.

So, any pointers as to where to look? I've checked the vacuum tap and on on and res it seems to not leak with the engine off and flows well on prime. Had new plugs in August.  

I just thought while the bodywork is off at paint it might be prudent to get it sorted.

[Superdunc]

1 minute ago, Andy J said:

So, the RD that I bought in August has a niggly little fault. If left for a few days it's a bugger to start. It needs multiple kicks to get it fired up, sometimes taking a minute or two of kicking. Once running however it will play nice all day, starting first or second kick every time. It will even start ok the following morning. But leave it a few days and it's back to square one.

So, any pointers as to where to look? I've checked the vacuum tap and on on and res it seems to not leak with the engine off and flows well on prime. Had new plugs in August.  

I just thought while the bodywork is off at paint it might be prudent to get it sorted.

Is the battery holding a charge? first minute of kicking might be topping the battery up.

[Tom Mac]

is the choke circuit on the carbs working?

are you opening the throttle whilst kicking?

any evidence of petrol coming out of the end cans when it does start?

[Andy J]

Well the choke clicks out but it doesn't seem to make any difference to the running if it's out or not. Not tried it when it warmed up to see if it runs rough with the choke out.

I've tried both no throttle, full throttle and all points in between. When it does run it seems to be on a tiny bit of throttle or none at all.

Not looked for fuel but I will.

Not had 2 stroke for about 30 years so I'm very out of touch with it all and not had carbs since my GSXR1100 about 10 years ago!

[Andy J]

2 hours ago, Superdunc said:

Is the battery holding a charge? first minute of kicking might be topping the battery up.

Battery was flat before I bought it but it was charged and seems to be holding charge. If I put the ignition on the powervalve cycles and the lights come on and the neutral light. It didn't do this when the battery was flat. It wouldn't hurt to put it on charge for a couple of hours to rule that out.

[trackdaybob]

Stick new plugs in. Can't do any harm. 

[bogman]

Reed petals

[bogman]

A sign of poor starting 

[Andy J]

4 hours ago, trackdaybob said:

Stick new plugs in. Can't do any harm. 

Had new plugs in August. Its only done maybe 200 miles since.

[Andy J]

2 hours ago, bogman said:

A sign of poor starting 

All the time or only when it's been standing? Starts fine if it's been run in the last 24hrs.

[bogman]

Cold starts mainly 

[CRM]

My N1 was similar. 
Loads of boots perhaps 10 or 15 to get it to fire then it would lethargically wheeze into life and be fine for days on end.

£3k later, turns out centre crank seal was goosed and mains were also pretty knackered pattern items.
Ok so there were plenty of other faults (rebuilt averagely with no care for measurements and liberal use of pattern parts) in the 3k bill, but the difference is going from barely 48 bhp at the wheel to now a healthy 61 with zeel ignition still on stock pipes and setting up. 

Now starts within 3 - 4 kicks after a couple of weeks lay up.

Ensure the fuel tap and vacuum is healthy, carbs are not pissing fuel into the cylinders, reeds, plugs and caps are genuine NGK items (those horrible pattern OEM items from Yambits will rob you of loads of power) 

[Andy J]

5 hours ago, CRM said:

My N1 was similar. 
Loads of boots perhaps 10 or 15 to get it to fire then it would lethargically wheeze into life and be fine for days on end.

£3k later, turns out centre crank seal was goosed and mains were also pretty knackered pattern items.
Ok so there were plenty of other faults (rebuilt averagely with no care for measurements and liberal use of pattern parts) in the 3k bill, but the difference is going from barely 48 bhp at the wheel to now a healthy 61 with zeel ignition still on stock pipes and setting up. 

Now starts within 3 - 4 kicks after a couple of weeks lay up.

Ensure the fuel tap and vacuum is healthy, carbs are not pissing fuel into the cylinders, reeds, plugs and caps are genuine NGK items (those horrible pattern OEM items from Yambits will rob you of loads of power) 

Bike is on 14k so it could be due an engine refresh. Fuel tap seems ok. It shuts off fine on on and res and seems to flow OK on prime. Is it worth rebuilding the tap while the tank is off for paint?

Is it worth putting aftermarket Boysen/Hytech type reeds on?

I've bought a couple of bits from Yambits but there seems to be a lot of folk on the RDLCcrazy forum that really don't rate them,not sure why? What are Wemoto like for stuff like plugs, caps etc?

I've read very good reports about Banshee coils as a good upgrade which helps with starting. While the bikes naked and the bodywork away at paint maybe worth putting some on? It looks pretty straightforward although mine is one coil with 2 outputs whereas Banshee coils are a pair with a single output? I've not really looked in to it too much yet.

[CRM]

Andy getting someone who knows them inside out like Dave at Mutts Nuts in Wetherby won't be a cheap job and get in the queue, he has a 12 month lead time at the moment i think. 
However results are good, workmanship is excellent and you pay for his knowledge. 
Mine needed a lot and i added to the bill with Zeel ECU and a few other things to make sure it was 100% right. 

genuine plugs and NGK aftermarket caps are worth doing. 
The gap on the pulse coil is important too, check the gap is not too large

[Andy J]

3 hours ago, CRM said:

Andy getting someone who knows them inside out like Dave at Mutts Nuts in Wetherby won't be a cheap job and get in the queue, he has a 12 month lead time at the moment i think. 
However results are good, workmanship is excellent and you pay for his knowledge. 
Mine needed a lot and i added to the bill with Zeel ECU and a few other things to make sure it was 100% right. 

genuine plugs and NGK aftermarket caps are worth doing. 
The gap on the pulse coil is important too, check the gap is not too large

Funnily enough I've just been looking at his site (again!) I am tempted to throw caution to the wind and have a full engine rebuild/check over but I fear it won't be cheap!

[mattyam]

there a piece of piss to work on really. if you do the labour yourself and send the crank/barrells off you will save a good few quid.first and foremost though eliminate the simple things. make sure plug caps are secured properly, the ht leads arent broken internally and so on.check the float heights, the float valves not leaking and pilot jets are clear. an ultrasonic clean wouldnt hurt. the choke does sound dubious though if it makes no difference to running. then id be looking a leaky crank seals.  to check the reeds takes 10 minutes to get the out. fit some boyesens, there not expensive

[mattyam]

ps im pretty sure they run without a battery but its been a few years since i had powervalves

[Andy J]

8 hours ago, mattyam said:

ps im pretty sure they run without a battery but its been a few years since i had powervalves

This one did. It would fire up and run with a flat battery but funnily enough there was no neutral light. I got the seller to charge the battery and I went back a few days later to ensure there was indeed a little green light and that the powervalves did their little dance when the ignition was turned on.

[Jenny Pryde]

Yep. Charged battery not required.