Repsol Honda riders Casey Stoner and Dani Pedrosa gave the 'completely new' version of the RC213V a mixed verdict during Monday's post-race test at Mugello.

The new engine and chassis, intended for 2013, was brought to Mugello to be evaluated as a potential race option for later this season.

HRC is battling to overcome chatter and front-tyre squashing issues with the latest Bridgestone rubber, as it seeks to get Pedrosa and Stoner back on terms with Yamaha's title leader Jorge Lorenzo.

The good news for Honda was that both riders liked the new engine. However only Pedrosa preferred the chassis and the Spaniard fell on just his third lap with the new bike due to a downshift error.

"We tested many things today and I'm happy because we found some positives with the new engine and also with the new chassis that can help us in the second part of the season," said Pedrosa.

"I was really hoping for some improvements after the issues we have had with the extra weight, chattering and the front tyres and in this test we made a step forward."

Both Pedrosa and Stoner set their best Monday laps on the 2012 bike. As in Sunday's race, Pedrosa was second to Lorenzo, with a best lap just 0.114s slower.

Pedrosa is hoping the new engine, at least, will be ready for the forthcoming Laguna Seca weekend and also seems open to trying the new chassis if available.

The Spaniard is currently 19 points behind countryman Lorenzo with nine of 18 rounds to go.

"Honda is working very hard and I'm sure they will do their best to be able to supply us the new parts for Laguna and the following races, but we'll see if it's possible with the engine allocations; anyway, it would be very good for us," said Pedrosa.

"The engine is better into the corner, the engine brake is smoother and the bike is not so sharp when you close the throttle, so this helps you to get into the corner.

"I made my best lap time on my current bike; it's normal as I'm used to it. With the new bike I made a mistake shifting gears and I had a small crash on my third lap, so I couldn't do a longer run, but the feeling was also positive".

Reigning champion Stoner - who has gone from the joint title lead to 37 points from Lorenzo in the space of two races - hopes to fit the new engine into the present chassis for the US Grand Prix.

"We had a new engine and new chassis to test today. With the engine we found some improvements, a little smoother and some more power. As far as chassis goes I didn't find any real benefits, we tried many different things but couldn't get a better feeling," declared Stoner.

"There were a few small areas that improved but nothing in terms of performance or for the lap time, just a marginally better feeling under braking."

Stoner, who struggled throughout the Mugello weekend and finished eighth after running off track in the race, admitted he had been hoping for more.

"It wasn't really the test we were looking for, we had hoped to find something to help us get rid of the chatter and give us some more feeling in the middle of the corner but unfortunately we didn't find this," he said.

"If we can have the new engine with the current chassis, it's the best combination, but we're not sure if we can have it in time for Laguna Seca, we'll have to wait and see".

Stoner was third quickest at the test, lapping within 0.116s of Lorenzo on his 47th and final lap of the day.

HRC executive vice president Shuhei Nakamoto pledged to do all he can to make the new engine available for the first American round from July 27-29.

"Both riders gave positive feedback with the new engine and we will do our best to provide it to them already next week in Laguna Seca," he said.

"The new chassis has good points and bad points, Dani seems to like it and we will do our best to bring it for him at the next round. Casey doesn't find what he was looking for in this new chassis; to reduce the chatter.

"We have some more ideas to solve this and we will continue working to improve our machine but we can be reasonably happy of today's result."