Thanks for reply. Exaust repacked. I have spoken with Nigel Birkett today and he has given me some setting to do with the carb. Apparently these 2015 300s were problematic regards getting the carburation right.
Hi there, just wondering if anyone might have any suggestions that I might try to resolve my issue.
the bike is a 2015 Scorpa 300 twenty model. I bought it earlier this year and have had a few issues, so I will list what I have changed so far trying to sort the bike. It s running a keihin carb.
crank seals replaced, Reed valves and inlet block changed, new barrel and piston as it seized, new CDI, I also have set carb float height and tried a no3 slide, but it’s back on the standard 3.5 slide. It’s currently running a 128 main jet.
The bike runs fine at low revs, but if you try to open it up say in a hill climb or over the moor then it runs poorly and starts pinking. I have a 130 main jet that I am going to try, but if anyone has any other ideas what could be the problem that would be great as I’ve now spent so much trying to get this bike sorted out it’s doing my head in.
maybe I should have tried the bigger main jet before posting here, but I will try it this week. Someone I ride with said had the new CDI been mapped to the bike, but I’ve never heard about that and don’t know if that is a requirement of installing one.
During the lock down I’ve been constructing a section in the back garden. Still a bit to go but getting the base laid in then will start making alterations to make it more challenging.
closest area is also going to double a steps down into garden steeper than the photo makes it look.
Hi there just wondered if anyone has experienced a problem like I’m having.
my 15 repsol starts fine and runs away fine, but after a bit it starts dropping the engine speed on shutting off the throttle and it goes below idle speed and stalls. It will immediately start again and idle away fine, but drive the bike again and it will drop the idle speed and stall.
So it’s happy idling from start up, but drops off from shuttling the throttle off. Seems to be once it’s warm. While running it takes full throttle and seems fine, but once shutting off it will stall.
I have cleaned the throttle body main venturi butterfly passage and the air passage that is in use when idling. There had been an alteration done to the bike prior to me buying it and the head breather oil catch tank had been moved to under the seat and wasn’t doing it’s job and oil was getting into the airbox then going through the throttle body. I have put a small breather filter up under the headstock.
Its my first montesa 4rt so not really that well read on the injection setup.
Hi Guys. Was out again today. Had changed plug,checked coolant. Slackened off the throttle cable and brought the idle speed up, but it continued to do the same and drop the idle speed on shutting off throttle. I’ve taken the tank off to check it. Looks spotless inside. Is the teabag type filter in the small sump below the pump? Lifting the gasket I ca see a green mesh. Is it within the mesh. I will attach a photo.
Any advice welcome I was thinking to get the throttle body off and see if it needed cleaning. It’s all new to me as I’ve been a Gasgas/ carb user until this bike being my first fuel injected so it’s all a bit of a mystery to me??
Hi there can anyone recommend a company in the uk that do rebores. My 198A 250sherpa is in need of a rebores and wondered if anyone could advise on who to use and estimated cost of he rebore.
What year is the bike? Might give some more insight to what could be the problem...
Might consider that plug change you indicated, always wort roiling out the small stuff.
Other considerations, low on coolant so might be heating up the fuel, valve clearance, water pump same as coolant... just some things off the top of my head.
Hi there, can anyone shed some light on what could be causing my 4rt to start dropping it’s idle speed when it’s hot. It’s fine for the first hour or so then after it’s been revving when shutting off throttle the engine speed drops below idle speed and stalls. The bike otherwise is fine. I changed the air filter prior to going out on Sunday, thinking it may have been a dirty air filter.
but it did the same after it had been running for a while.
Could it be the plug starting to fail. I’ve never done anything with the fuel system. Ie throttle body or fuel tank, but wondered if it could be one of those causing problems.
Thanks Bondy, yeh it’s going to be stripped down. The detent plunger is quite worn looking so will replace it while am at it. It’s turning over freely now but I’d say the bearings sound a little rough. It’s getting a pretty much full rework of the bike as I bought it unseen but complete and it’s needing a reasonable bit of work doing to it all. I had a 199A a few years ago that I restored, but it was almost too nice to ride, it was sold to a collector p, but this one is going to be ridden for sure hopefully have it done for the new 2 day in September in Kinlochleven if I can get an entry
Well after soaking the crank in I noted deblock oil over night it was feeling that there was more movement at the crank. Worked it gently back and fore and it has come free so it’s been a frozen crank ?. So full strip and rebuild required for sure.
Haha. Yeh might be better to get her to have a crack at it. The barrel is off the bike. I bought the bike a couple of months ago. And am sure it was turning over when I got it as a mate picked it up for me so it was unseen. Though my brother in law who had told me about it said it was supposed to have been a runner.
I did try selecting neutral while it was removed and as you say I might have locked it up. Bugger.
Hi there, I’m just setting about a restoration of a Sherpa 250 198A. I’ve drained the oils which were not in a good way. But I went to turn the engine over and it seemed as though it was jammed. Lots of head scratching, and eventually left it and went back into the house. Was speaking with my wife and she said what had I done exactly and was there anything that was not in place. My thoughts are that the detent plunger bolt is removed.
Poor mid to top end performance Scorpa 300 twenty
in Scorpa
Posted
We can only get 95ron fuel where I live. I’ve just tried some octane booster, but didn’t help.